Who's left in the E6 biz?

Robert Vervoordt wrote:

On Thu, 16 Sep 2004 15:33:26 GMT, Donald Qualls
wrote:


Robert Vervoordt wrote:


In any event, your ideas are interesting, and so should be your
results.

Thanks, I'll have to try a high-solvent developer for negatives once I
get a roll of the Fomapan R to test.


Remember, the Silver solvent used for the finely formed anti-halo
layer in reversal processes is usually a Thiocyante or some other,
proprietary, item. These are very powerful. and are not usually
equalled by high Sulfite formulations. I know this from experiments
with D-76, even using up to 180 grams in the first developer. I had
to add Thiocyanate to get control over the AH layer. When you do
experiment, look into the use of small additions of Iodide to the
first developer to keep the solvent from aggressively attacking the
upper layers of the emulsion, itself. If uncontrolled, the results
will be Blueish, tending toward Cyan, or even Green, if it is very
severe. The Iodide will retard the stronger Thiocyanate's action,
working from the topmost layer downward. It warms things up, but
requires initial testing to nail the right amounts for your process,
if you are compounding, or using some unusual emulsion. This was
patented by Ansco a long tome ago and seems to have been adopted by
all other E6 manufacturers, subsequently. Look into the literature,
it should be clear. This is a consideration for color reversal, not
monochrome.

So essentially, we'd have a weak bleach in conjunction with first
development -- doesn't this tend to weaken highlights in the final
reversed image (or weaken the shadows in a negative)? Or does this
contribute to the increase in film speed of the reversal compared to the
same film developed as a negative? My concern would be dissolving away
the image as well as the AH layer; I think I'd be more comfortable with
a C-41 based process to get a negative, even though it would require
adding dye couplers to the color developer; other than the dye coupler,
all that would really be required is a straight C-41 process with
temperature reduced to avoid emulsion damage, and let the bleach and fix
take care of the silver and unexposed halide.

I'm not the least interested in fooling with alterations to color
development; if/when I get into developing my own color, I'll plan to go
with straight C-41 and/or E-6 using a commercially made chemical system.
I have done a little work with my own B&W developer modifications,
including a monobath based on HC-110 and commercial rapid fixer and
cofee-based Caffenol and Caffenol LC (the latter a POTA replacement for
microfilm type emulsions).


The Fomapan R is probably best kept for its intended use as a reversal
film; I can see situations where reversal would be very useful, frex in
duplicating 35 mm negatives with a modified camera for contact exposure
or making positive masks in 35 mm.


Things do get complicated when we are using a film for more than one
application, but using one film cuts out a number of other issues as
well as cost. Yuu know your needs better than anyone. Your
experiments should provide some new aspects for many of us; me, for
sure.

For use in my subminiature cameras, having a film that's already in 16
mm width is worth a lot compared to slitting, but my current system for
developing that film has limitations, too; some upgrades are in order
before I undertake a process that involves more than 3-4 baths. Film is
held in the homebuilt tank by masking tape, and the tape sometimes lets
go (based on development, generally after fixing but before completion
of wetting agent treatment); that can cause damage, of course. A film I
can develop directly as a negative is good, and one that doesn't require
anything more exotic than Caffenol LC or a high dilution of HC-110 is
more welcome than needing to mix thiocyanate into the developer; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?), but the Kodak emulsions
don't require special handling to develop as negatives, and further are
reported to give more speed as negatives compared to Kodak's recommended
low-contrast reversal process for movie film -- the Tri-X Reversal at or
close to the 320-400 range of ordinary Tri-X, and the Plus-X Reversal at
100-125.

The main original attraction of the Fomapan R was the $8 price for a 25
foot roll in Double 8 format (directly usable in 10x14 mm subminiature
cameras); if I have to go through a bunch of rigamarole to get a
negative from it, I'm better off using multiple films for multiple
purposes, as I already do (Tri-X in 35 mm, TMY in 120, and Copex Rapid
in 16 mm).

FWIW, Foma's recommended process uses Fomadon (which seems to be a
generic MQ developer approximately similar to D-76) for both first and
second dev, and depends on the bleach step to remove the AH layer.


That's a bit different from the usual procedure. Most reversal
processes use a vigorous first developer and impart a speed and
contrast boost to the usual negative emulsion used as a basis. The
image is formed from the remaining Silver left after first development
and as a result, there is a net gain in the ratio of speed to
graininess, while the contrast is elevated to a level suitable for
projection viewing. It's one of those win-win situations we rarely
get to enjoy.

I could have misremembered the Fomapan R process -- specifically, the
first developer might in fact contain an admixture of thiocyanate or
other bleaching agent. I'd have to go back to the data page to verify,
but I've already pretty much decided against the Fomapan after learning
I could still get the Kodak emulsions in either 16 mm single perf or
Double 8.

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

Robert Vervoordt wrote:

On Thu, 16 Sep 2004 15:33:26 GMT, Donald Qualls
wrote:


Robert Vervoordt wrote:


In any event, your ideas are interesting, and so should be your
results.

Thanks, I'll have to try a high-solvent developer for negatives once I
get a roll of the Fomapan R to test.


Remember, the Silver solvent used for the finely formed anti-halo
layer in reversal processes is usually a Thiocyante or some other,
proprietary, item. These are very powerful. and are not usually
equalled by high Sulfite formulations. I know this from experiments
with D-76, even using up to 180 grams in the first developer. I had
to add Thiocyanate to get control over the AH layer. When you do
experiment, look into the use of small additions of Iodide to the
first developer to keep the solvent from aggressively attacking the
upper layers of the emulsion, itself. If uncontrolled, the results
will be Blueish, tending toward Cyan, or even Green, if it is very
severe. The Iodide will retard the stronger Thiocyanate's action,
working from the topmost layer downward. It warms things up, but
requires initial testing to nail the right amounts for your process,
if you are compounding, or using some unusual emulsion. This was
patented by Ansco a long tome ago and seems to have been adopted by
all other E6 manufacturers, subsequently. Look into the literature,
it should be clear. This is a consideration for color reversal, not
monochrome.

So essentially, we'd have a weak bleach in conjunction with first
development -- doesn't this tend to weaken highlights in the final
reversed image (or weaken the shadows in a negative)? Or does this
contribute to the increase in film speed of the reversal compared to the
same film developed as a negative? My concern would be dissolving away
the image as well as the AH layer; I think I'd be more comfortable with
a C-41 based process to get a negative, even though it would require
adding dye couplers to the color developer; other than the dye coupler,
all that would really be required is a straight C-41 process with
temperature reduced to avoid emulsion damage, and let the bleach and fix
take care of the silver and unexposed halide.

I'm not the least interested in fooling with alterations to color
development; if/when I get into developing my own color, I'll plan to go
with straight C-41 and/or E-6 using a commercially made chemical system.
I have done a little work with my own B&W developer modifications,
including a monobath based on HC-110 and commercial rapid fixer and
cofee-based Caffenol and Caffenol LC (the latter a POTA replacement for
microfilm type emulsions).


The Fomapan R is probably best kept for its intended use as a reversal
film; I can see situations where reversal would be very useful, frex in
duplicating 35 mm negatives with a modified camera for contact exposure
or making positive masks in 35 mm.


Things do get complicated when we are using a film for more than one
application, but using one film cuts out a number of other issues as
well as cost. Yuu know your needs better than anyone. Your
experiments should provide some new aspects for many of us; me, for
sure.

For use in my subminiature cameras, having a film that's already in 16
mm width is worth a lot compared to slitting, but my current system for
developing that film has limitations, too; some upgrades are in order
before I undertake a process that involves more than 3-4 baths. Film is
held in the homebuilt tank by masking tape, and the tape sometimes lets
go (based on development, generally after fixing but before completion
of wetting agent treatment); that can cause damage, of course. A film I
can develop directly as a negative is good, and one that doesn't require
anything more exotic than Caffenol LC or a high dilution of HC-110 is
more welcome than needing to mix thiocyanate into the developer; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?), but the Kodak emulsions
don't require special handling to develop as negatives, and further are
reported to give more speed as negatives compared to Kodak's recommended
low-contrast reversal process for movie film -- the Tri-X Reversal at or
close to the 320-400 range of ordinary Tri-X, and the Plus-X Reversal at
100-125.

The main original attraction of the Fomapan R was the $8 price for a 25
foot roll in Double 8 format (directly usable in 10x14 mm subminiature
cameras); if I have to go through a bunch of rigamarole to get a
negative from it, I'm better off using multiple films for multiple
purposes, as I already do (Tri-X in 35 mm, TMY in 120, and Copex Rapid
in 16 mm).

FWIW, Foma's recommended process uses Fomadon (which seems to be a
generic MQ developer approximately similar to D-76) for both first and
second dev, and depends on the bleach step to remove the AH layer.


That's a bit different from the usual procedure. Most reversal
processes use a vigorous first developer and impart a speed and
contrast boost to the usual negative emulsion used as a basis. The
image is formed from the remaining Silver left after first development
and as a result, there is a net gain in the ratio of speed to
graininess, while the contrast is elevated to a level suitable for
projection viewing. It's one of those win-win situations we rarely
get to enjoy.

I could have misremembered the Fomapan R process -- specifically, the
first developer might in fact contain an admixture of thiocyanate or
other bleaching agent. I'd have to go back to the data page to verify,
but I've already pretty much decided against the Fomapan after learning
I could still get the Kodak emulsions in either 16 mm single perf or
Double 8.

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

On Fri, 17 Sep 2004 17:38:37 GMT, Donald Qualls
wrote:

Robert Vervoordt wrote:

On Thu, 16 Sep 2004 15:33:26 GMT, Donald Qualls
wrote:


Robert Vervoordt wrote:


In any event, your ideas are interesting, and so should be your
results.

Thanks, I'll have to try a high-solvent developer for negatives once I
get a roll of the Fomapan R to test.


Remember, the Silver solvent used for the finely formed anti-halo
layer in reversal processes is usually a Thiocyante or some other,
proprietary, item. These are very powerful. and are not usually
equalled by high Sulfite formulations. I know this from experiments
with D-76, even using up to 180 grams in the first developer. I had
to add Thiocyanate to get control over the AH layer. When you do
experiment, look into the use of small additions of Iodide to the
first developer to keep the solvent from aggressively attacking the
upper layers of the emulsion, itself. If uncontrolled, the results
will be Blueish, tending toward Cyan, or even Green, if it is very
severe. The Iodide will retard the stronger Thiocyanate's action,
working from the topmost layer downward. It warms things up, but
requires initial testing to nail the right amounts for your process,
if you are compounding, or using some unusual emulsion. This was
patented by Ansco a long tome ago and seems to have been adopted by
all other E6 manufacturers, subsequently. Look into the literature,
it should be clear. This is a consideration for color reversal, not
monochrome.

So essentially, we'd have a weak bleach in conjunction with first
development

The bleach is not involved in this discussion. The bleach is just
used the same way that it would be in a ny E-6 or BW reversal
process. The modifications I'm talking about are for the first
developers only.


- doesn't this tend to weaken highlights in the final
reversed image (or weaken the shadows in a negative)? Or does this
contribute to the increase in film speed of the reversal compared to the
same film developed as a negative? My concern would be dissolving away
the image as well as the AH layer;

That's what the manyfacturer's testing determined. The aggressive
solvent gets rod of the AH layer Silver in a very short time, long
before it can attack any image forming Silver. It works, they made
sure.


I think I'd be more comfortable with
a C-41 based process to get a negative, even though it would require
adding dye couplers to the color developer; other than the dye coupler,
all that would really be required is a straight C-41 process with
temperature reduced to avoid emulsion damage, and let the bleach and fix
take care of the silver and unexposed halide.

I can't repeat often enough that a suitable negative developer will
not be up to the demands of a reversal process, unless it is quite
seriously modified. But go ahead and try out C-41. I never used it,
so I will find your results to be new info, even if I am expecting a
disaster. The fun is in the details,

Going house hunting now, so I'll catch up tonight.

Good luck and never forget to have fun.



Robert Vervoordt, MFA

On Fri, 17 Sep 2004 17:38:37 GMT, Donald Qualls
wrote:

Robert Vervoordt wrote:

On Thu, 16 Sep 2004 15:33:26 GMT, Donald Qualls
wrote:


Robert Vervoordt wrote:



I'm not the least interested in fooling with alterations to color
development; if/when I get into developing my own color, I'll plan to go
with straight C-41 and/or E-6 using a commercially made chemical system.
I have done a little work with my own B&W developer modifications,
including a monobath based on HC-110 and commercial rapid fixer and
cofee-based Caffenol and Caffenol LC (the latter a POTA replacement for
microfilm type emulsions).

I followed those threads.

The Fomapan R is probably best kept for its intended use as a reversal
film; I can see situations where reversal would be very useful, frex in
duplicating 35 mm negatives with a modified camera for contact exposure
or making positive masks in 35 mm.


Things do get complicated when we are using a film for more than one
application, but using one film cuts out a number of other issues as
well as cost. Yuu know your needs better than anyone. Your
experiments should provide some new aspects for many of us; me, for
sure.

For use in my subminiature cameras, having a film that's already in 16
mm width is worth a lot compared to slitting, but my current system for
developing that film has limitations, too; some upgrades are in order
before I undertake a process that involves more than 3-4 baths. Film is
held in the homebuilt tank by masking tape, and the tape sometimes lets
go (based on development, generally after fixing but before completion
of wetting agent treatment); that can cause damage, of course. A film I
can develop directly as a negative is good, and one that doesn't require
anything more exotic than Caffenol LC or a high dilution of HC-110 is
more welcome than needing to mix thiocyanate into the developer

Any reversal film can be developed as a negative. In point of fact.
all reversal films are developed as negatives, before they are
*reversed*.

; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?),

No, as a method of clearing extremely fine Silver from the highlights.
This is only a consideration for reversal processing and the nead for
very clear highlights in projection. When it comes to negatives and
printing, the slight density in the highlights may be actually an
advantage as it would limit the range of negative densities slightly.

but the Kodak emulsions
don't require special handling to develop as negatives,

Neither do the others. they are all very much the same animals.

and further are
reported to give more speed as negatives compared to Kodak's recommended
low-contrast reversal process for movie film -- the Tri-X Reversal at or
close to the 320-400 range of ordinary Tri-X, and the Plus-X Reversal at
100-125.

No, no no! That's all wrong. The emulsion that is called Tri-X
Reversal is actually Plus-X Negative at its core. Since reversal
processing gives about a stop and a third more effective speed, along
with finer grain in the final image, Kodak can get away with the
renaming. Actually, leaving aside the confusion the renaming causes
when going into the considerations we are discussing, it serves a
purpose in use as the similarly named films are suited for similar
uses.

I listed this before, but here it is again:

Panatomic-X, XT-Pan, Background-X = Plus-X Reversal
Plus-X Pan, Plus-X Negative. = Tri-X Reversal
Tri-X Pan, Double-X Negative = Four-X Reversal

Now, check out the speeds.

Pan-X 25, Plus-X Rev 80
Plus-X Neg 80, Tri-X Rev 200
Double X neg 200, Four-X Rev 400

In effect, using any negative emulsion in a reversal process will
generate an effective sp0eed increase for exposure considerations.


The main original attraction of the Fomapan R was the $8 price for a 25
foot roll in Double 8 format (directly usable in 10x14 mm subminiature
cameras); if I have to go through a bunch of rigamarole to get a
negative from it,

You don't. Just use it as the slower negative it is, no matter what
name the maufacturer uses for it. The principles apply whether it's
Kodak, Foma, color or monochrome.

I'm better off using multiple films for multiple
purposes, as I already do (Tri-X in 35 mm, TMY in 120, and Copex Rapid
in 16 mm).

Maybe not. Kodak's naming just bollixed up the whole concept of how
emulsions are applied to reversal processes. Works fine for the
exposure part of the application, though.

FWIW, Foma's recommended process uses Fomadon (which seems to be a
generic MQ developer approximately similar to D-76) for both first and
second dev, and depends on the bleach step to remove the AH layer.


That's a bit different from the usual procedure. Most reversal
processes use a vigorous first developer and impart a speed and
contrast boost to the usual negative emulsion used as a basis. The
image is formed from the remaining Silver left after first development
and as a result, there is a net gain in the ratio of speed to
graininess, while the contrast is elevated to a level suitable for
projection viewing. It's one of those win-win situations we rarely
get to enjoy.

I could have misremembered the Fomapan R process -- specifically, the
first developer might in fact contain an admixture of thiocyanate or
other bleaching agent.

Keep working on getting this straight. The /Thiocyanate is a Silver
solvent, not a bleach. It is used in the developer. The leaching
agent is different and used in the bleach, not the developer, of a
reversal process.

I'd have to go back to the data page to verify,
but I've already pretty much decided against the Fomapan after learning
I could still get the Kodak emulsions in either 16 mm single perf or
Double 8.

Isn't Fomapan cheaper and more available?

Robert Vervoordt, MFA

On Fri, 17 Sep 2004 17:38:37 GMT, Donald Qualls
wrote:

Robert Vervoordt wrote:

On Thu, 16 Sep 2004 15:33:26 GMT, Donald Qualls
wrote:


Robert Vervoordt wrote:



I'm not the least interested in fooling with alterations to color
development; if/when I get into developing my own color, I'll plan to go
with straight C-41 and/or E-6 using a commercially made chemical system.
I have done a little work with my own B&W developer modifications,
including a monobath based on HC-110 and commercial rapid fixer and
cofee-based Caffenol and Caffenol LC (the latter a POTA replacement for
microfilm type emulsions).

I followed those threads.

The Fomapan R is probably best kept for its intended use as a reversal
film; I can see situations where reversal would be very useful, frex in
duplicating 35 mm negatives with a modified camera for contact exposure
or making positive masks in 35 mm.


Things do get complicated when we are using a film for more than one
application, but using one film cuts out a number of other issues as
well as cost. Yuu know your needs better than anyone. Your
experiments should provide some new aspects for many of us; me, for
sure.

For use in my subminiature cameras, having a film that's already in 16
mm width is worth a lot compared to slitting, but my current system for
developing that film has limitations, too; some upgrades are in order
before I undertake a process that involves more than 3-4 baths. Film is
held in the homebuilt tank by masking tape, and the tape sometimes lets
go (based on development, generally after fixing but before completion
of wetting agent treatment); that can cause damage, of course. A film I
can develop directly as a negative is good, and one that doesn't require
anything more exotic than Caffenol LC or a high dilution of HC-110 is
more welcome than needing to mix thiocyanate into the developer

Any reversal film can be developed as a negative. In point of fact.
all reversal films are developed as negatives, before they are
*reversed*.

; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?),

No, as a method of clearing extremely fine Silver from the highlights.
This is only a consideration for reversal processing and the nead for
very clear highlights in projection. When it comes to negatives and
printing, the slight density in the highlights may be actually an
advantage as it would limit the range of negative densities slightly.

but the Kodak emulsions
don't require special handling to develop as negatives,

Neither do the others. they are all very much the same animals.

and further are
reported to give more speed as negatives compared to Kodak's recommended
low-contrast reversal process for movie film -- the Tri-X Reversal at or
close to the 320-400 range of ordinary Tri-X, and the Plus-X Reversal at
100-125.

No, no no! That's all wrong. The emulsion that is called Tri-X
Reversal is actually Plus-X Negative at its core. Since reversal
processing gives about a stop and a third more effective speed, along
with finer grain in the final image, Kodak can get away with the
renaming. Actually, leaving aside the confusion the renaming causes
when going into the considerations we are discussing, it serves a
purpose in use as the similarly named films are suited for similar
uses.

I listed this before, but here it is again:

Panatomic-X, XT-Pan, Background-X = Plus-X Reversal
Plus-X Pan, Plus-X Negative. = Tri-X Reversal
Tri-X Pan, Double-X Negative = Four-X Reversal

Now, check out the speeds.

Pan-X 25, Plus-X Rev 80
Plus-X Neg 80, Tri-X Rev 200
Double X neg 200, Four-X Rev 400

In effect, using any negative emulsion in a reversal process will
generate an effective sp0eed increase for exposure considerations.


The main original attraction of the Fomapan R was the $8 price for a 25
foot roll in Double 8 format (directly usable in 10x14 mm subminiature
cameras); if I have to go through a bunch of rigamarole to get a
negative from it,

You don't. Just use it as the slower negative it is, no matter what
name the maufacturer uses for it. The principles apply whether it's
Kodak, Foma, color or monochrome.

I'm better off using multiple films for multiple
purposes, as I already do (Tri-X in 35 mm, TMY in 120, and Copex Rapid
in 16 mm).

Maybe not. Kodak's naming just bollixed up the whole concept of how
emulsions are applied to reversal processes. Works fine for the
exposure part of the application, though.

FWIW, Foma's recommended process uses Fomadon (which seems to be a
generic MQ developer approximately similar to D-76) for both first and
second dev, and depends on the bleach step to remove the AH layer.


That's a bit different from the usual procedure. Most reversal
processes use a vigorous first developer and impart a speed and
contrast boost to the usual negative emulsion used as a basis. The
image is formed from the remaining Silver left after first development
and as a result, there is a net gain in the ratio of speed to
graininess, while the contrast is elevated to a level suitable for
projection viewing. It's one of those win-win situations we rarely
get to enjoy.

I could have misremembered the Fomapan R process -- specifically, the
first developer might in fact contain an admixture of thiocyanate or
other bleaching agent.

Keep working on getting this straight. The /Thiocyanate is a Silver
solvent, not a bleach. It is used in the developer. The leaching
agent is different and used in the bleach, not the developer, of a
reversal process.

I'd have to go back to the data page to verify,
but I've already pretty much decided against the Fomapan after learning
I could still get the Kodak emulsions in either 16 mm single perf or
Double 8.

Isn't Fomapan cheaper and more available?

Robert Vervoordt, MFA

Robert Vervoordt wrote:
On Fri, 17 Sep 2004 17:38:37 GMT, Donald Qualls
wrote:

For use in my subminiature cameras, having a film that's already in 16
mm width is worth a lot compared to slitting, but my current system for
developing that film has limitations, too; some upgrades are in order
before I undertake a process that involves more than 3-4 baths. Film is
held in the homebuilt tank by masking tape, and the tape sometimes lets
go (based on development, generally after fixing but before completion
of wetting agent treatment); that can cause damage, of course. A film I
can develop directly as a negative is good, and one that doesn't require
anything more exotic than Caffenol LC or a high dilution of HC-110 is
more welcome than needing to mix thiocyanate into the developer


Any reversal film can be developed as a negative. In point of fact.
all reversal films are developed as negatives, before they are
*reversed*.

Surely, but with Fomapan R, the negative is impossible to see because of
the (not yet removed) silver AH layer. If I develop Fomapan R in, say,
HC-110 Dilution B, I'll get a solid black strip of film. In a reversal
process, the bleach step would remove that layer. I'm unclear on what
you're saying happens in the developer (or first dev, for reversal).
More on that question below.

; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?),


No, as a method of clearing extremely fine Silver from the highlights.
This is only a consideration for reversal processing and the nead for
very clear highlights in projection. When it comes to negatives and
printing, the slight density in the highlights may be actually an
advantage as it would limit the range of negative densities slightly.

Okay, fine silver in the highlights (after reversal) *is* fog, is it
not? It's a high Dmin in a film that ought to have a very low Dmin;
that sounds like fog to me.

but the Kodak emulsions
don't require special handling to develop as negatives,


Neither do the others. they are all very much the same animals.

No, anything with a silver AH layer requires *something* different from
conventional B&W development to produce any kind of usable negative,
because the AH layer won't wash out the way antihalation dyes do in
conventional negative films (we often see them as purple or pink color
in the used developer).

and further are
reported to give more speed as negatives compared to Kodak's recommended
low-contrast reversal process for movie film -- the Tri-X Reversal at or
close to the 320-400 range of ordinary Tri-X, and the Plus-X Reversal at
100-125.


No, no no! That's all wrong. The emulsion that is called Tri-X
Reversal is actually Plus-X Negative at its core. Since reversal
processing gives about a stop and a third more effective speed, along
with finer grain in the final image, Kodak can get away with the
renaming. Actually, leaving aside the confusion the renaming causes
when going into the considerations we are discussing, it serves a
purpose in use as the similarly named films are suited for similar
uses.

I listed this before, but here it is again:

Panatomic-X, XT-Pan, Background-X = Plus-X Reversal
Plus-X Pan, Plus-X Negative. = Tri-X Reversal
Tri-X Pan, Double-X Negative = Four-X Reversal

Now, check out the speeds.

Pan-X 25, Plus-X Rev 80
Plus-X Neg 80, Tri-X Rev 200
Double X neg 200, Four-X Rev 400

In effect, using any negative emulsion in a reversal process will
generate an effective sp0eed increase for exposure considerations.

Okay, I never saw that list before, but it was my understanding that
(for instance) Plus-X Reversal was pretty much the same as Plus-X Neg
and Plus-X Pan still photo emulsion, but movie films were expected to be
processed to much lower contrast, which lowers speed. I have heard
previously about speed increases with reversal processing of B&W
negative films like Panatomic X (EI 80 for reversal, 25 for negatives).
I didn't realize that the confusion with speeds and names in Kodak
movie stock was due to Kodak renaming the same emulsion just because of
the speed increase -- but what I'm hearing is that if I buy Tri-X
Reversal, and process it as negative film, I'll get something more like
Plus-X Pan than like Tri-X Pan, and if I want/need EI 400 for a
subminiature camera, I'm stuck slitting 400TX or TMY (or similar Ilford
or Agfa products); none of the existing movie stocks will give EI above
200 in D-76. Or does the above equivalence of Tri-X Pan with Double-X
Negative movie film suggest that the Double-X Neg is subject to speed
reduction by the low contrast movie negative development, and just gets
back to Tri-X speed with the "boost" of reversal?

This is all very confusing, and none of it would be necessary if I could
just buy ISO 400 B&W negative film in 16 mm (preferably Tri-X Pan, aka
400TX, which gives a very usable EI 1600 without much if any grain
increase when developed in Diafine).

The main original attraction of the Fomapan R was the $8 price for a 25
foot roll in Double 8 format (directly usable in 10x14 mm subminiature
cameras); if I have to go through a bunch of rigamarole to get a
negative from it,


You don't. Just use it as the slower negative it is, no matter what
name the maufacturer uses for it. The principles apply whether it's
Kodak, Foma, color or monochrome.

I do; at a minimum, I have to add thiocyanate to my developer to
dissolve the AH silver. And if I have to give up a stop or more from
the rated EI 100 as reversal film, giving EI 50 or even 32 as negative,
I'm better of with the EI 100 I'm already getting from Copex Rapid
(probably with finer grain as well), without any developer shenanigans
other than diluting HC-110 a lot or diluting Bath A of Diafine by 1:50.


I could have misremembered the Fomapan R process -- specifically, the
first developer might in fact contain an admixture of thiocyanate or
other bleaching agent.


Keep working on getting this straight. The /Thiocyanate is a Silver
solvent, not a bleach. It is used in the developer. The leaching
agent is different and used in the bleach, not the developer, of a
reversal process.

Okay, clarify this for me -- if something dissolves metallic silver, to
me, that's a bleach; it'll dissolve image silver and latent image specks
just as readily as it will remove a silver AH layer. As a result, it
seems it ought to eat up shadows in a negative and reduce speed, both by
killing the weakest/sparsest latent image specks before they can be
developed, and by dissolving away the least dense areas of the image
just as it dissolves the AH silver.

Silver is silver -- chemically, if you dissolve silver metal one place,
you'll dissolve it anywhere else in the same bath, and dissolving silver
*has to* cost you shadow speed in the negative.

If, OTOH, I develop in C-41 with added black dye coupler, I'm likely to
see a speed increase (over the same film in conventional B&W chemistry)
via dye amplification -- and the bleach step that's necessary anyway to
remove the silver from the dye image will remove the AH silver as well.
I'd just need a C-41 kit that doesn't require 100 F to work, though
color shifts aren't of concern for B&W; it might be sufficient just to
compensate the color dev time for normal contrast.

I'd have to go back to the data page to verify,
but I've already pretty much decided against the Fomapan after learning
I could still get the Kodak emulsions in either 16 mm single perf or
Double 8.


Isn't Fomapan cheaper and more available?

The last time this came up, someone (who, IIRC, had purchased it direct
from Kodak) said the Kodak stock was cheaper per foot (though it was
only available in something like 200 foot rolls, and only in 16 mm
single perf, as opposed to 25 feet of Double 8). That's a lot of film
for one guy with three working Minolta 16 format cameras and four
cassettes. But even J and C Photography can't seem to verify that
Fomapan R can be developed to a negative -- I asked them about it a
couple months ago, got an answer suggesting use of E-6 bleach, and when
I asked how to avoid bleaching the image as well as the AH layer, never
got a reply (they were waiting for information from Foma, and seemingly
never got it). The E-6 bleach would be perfect for reversal processing
-- but not much use if you want a negative.

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

Robert Vervoordt wrote:
On Fri, 17 Sep 2004 17:38:37 GMT, Donald Qualls
wrote:

For use in my subminiature cameras, having a film that's already in 16
mm width is worth a lot compared to slitting, but my current system for
developing that film has limitations, too; some upgrades are in order
before I undertake a process that involves more than 3-4 baths. Film is
held in the homebuilt tank by masking tape, and the tape sometimes lets
go (based on development, generally after fixing but before completion
of wetting agent treatment); that can cause damage, of course. A film I
can develop directly as a negative is good, and one that doesn't require
anything more exotic than Caffenol LC or a high dilution of HC-110 is
more welcome than needing to mix thiocyanate into the developer


Any reversal film can be developed as a negative. In point of fact.
all reversal films are developed as negatives, before they are
*reversed*.

Surely, but with Fomapan R, the negative is impossible to see because of
the (not yet removed) silver AH layer. If I develop Fomapan R in, say,
HC-110 Dilution B, I'll get a solid black strip of film. In a reversal
process, the bleach step would remove that layer. I'm unclear on what
you're saying happens in the developer (or first dev, for reversal).
More on that question below.

; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?),


No, as a method of clearing extremely fine Silver from the highlights.
This is only a consideration for reversal processing and the nead for
very clear highlights in projection. When it comes to negatives and
printing, the slight density in the highlights may be actually an
advantage as it would limit the range of negative densities slightly.

Okay, fine silver in the highlights (after reversal) *is* fog, is it
not? It's a high Dmin in a film that ought to have a very low Dmin;
that sounds like fog to me.

but the Kodak emulsions
don't require special handling to develop as negatives,


Neither do the others. they are all very much the same animals.

No, anything with a silver AH layer requires *something* different from
conventional B&W development to produce any kind of usable negative,
because the AH layer won't wash out the way antihalation dyes do in
conventional negative films (we often see them as purple or pink color
in the used developer).

and further are
reported to give more speed as negatives compared to Kodak's recommended
low-contrast reversal process for movie film -- the Tri-X Reversal at or
close to the 320-400 range of ordinary Tri-X, and the Plus-X Reversal at
100-125.


No, no no! That's all wrong. The emulsion that is called Tri-X
Reversal is actually Plus-X Negative at its core. Since reversal
processing gives about a stop and a third more effective speed, along
with finer grain in the final image, Kodak can get away with the
renaming. Actually, leaving aside the confusion the renaming causes
when going into the considerations we are discussing, it serves a
purpose in use as the similarly named films are suited for similar
uses.

I listed this before, but here it is again:

Panatomic-X, XT-Pan, Background-X = Plus-X Reversal
Plus-X Pan, Plus-X Negative. = Tri-X Reversal
Tri-X Pan, Double-X Negative = Four-X Reversal

Now, check out the speeds.

Pan-X 25, Plus-X Rev 80
Plus-X Neg 80, Tri-X Rev 200
Double X neg 200, Four-X Rev 400

In effect, using any negative emulsion in a reversal process will
generate an effective sp0eed increase for exposure considerations.

Okay, I never saw that list before, but it was my understanding that
(for instance) Plus-X Reversal was pretty much the same as Plus-X Neg
and Plus-X Pan still photo emulsion, but movie films were expected to be
processed to much lower contrast, which lowers speed. I have heard
previously about speed increases with reversal processing of B&W
negative films like Panatomic X (EI 80 for reversal, 25 for negatives).
I didn't realize that the confusion with speeds and names in Kodak
movie stock was due to Kodak renaming the same emulsion just because of
the speed increase -- but what I'm hearing is that if I buy Tri-X
Reversal, and process it as negative film, I'll get something more like
Plus-X Pan than like Tri-X Pan, and if I want/need EI 400 for a
subminiature camera, I'm stuck slitting 400TX or TMY (or similar Ilford
or Agfa products); none of the existing movie stocks will give EI above
200 in D-76. Or does the above equivalence of Tri-X Pan with Double-X
Negative movie film suggest that the Double-X Neg is subject to speed
reduction by the low contrast movie negative development, and just gets
back to Tri-X speed with the "boost" of reversal?

This is all very confusing, and none of it would be necessary if I could
just buy ISO 400 B&W negative film in 16 mm (preferably Tri-X Pan, aka
400TX, which gives a very usable EI 1600 without much if any grain
increase when developed in Diafine).

The main original attraction of the Fomapan R was the $8 price for a 25
foot roll in Double 8 format (directly usable in 10x14 mm subminiature
cameras); if I have to go through a bunch of rigamarole to get a
negative from it,


You don't. Just use it as the slower negative it is, no matter what
name the maufacturer uses for it. The principles apply whether it's
Kodak, Foma, color or monochrome.

I do; at a minimum, I have to add thiocyanate to my developer to
dissolve the AH silver. And if I have to give up a stop or more from
the rated EI 100 as reversal film, giving EI 50 or even 32 as negative,
I'm better of with the EI 100 I'm already getting from Copex Rapid
(probably with finer grain as well), without any developer shenanigans
other than diluting HC-110 a lot or diluting Bath A of Diafine by 1:50.


I could have misremembered the Fomapan R process -- specifically, the
first developer might in fact contain an admixture of thiocyanate or
other bleaching agent.


Keep working on getting this straight. The /Thiocyanate is a Silver
solvent, not a bleach. It is used in the developer. The leaching
agent is different and used in the bleach, not the developer, of a
reversal process.

Okay, clarify this for me -- if something dissolves metallic silver, to
me, that's a bleach; it'll dissolve image silver and latent image specks
just as readily as it will remove a silver AH layer. As a result, it
seems it ought to eat up shadows in a negative and reduce speed, both by
killing the weakest/sparsest latent image specks before they can be
developed, and by dissolving away the least dense areas of the image
just as it dissolves the AH silver.

Silver is silver -- chemically, if you dissolve silver metal one place,
you'll dissolve it anywhere else in the same bath, and dissolving silver
*has to* cost you shadow speed in the negative.

If, OTOH, I develop in C-41 with added black dye coupler, I'm likely to
see a speed increase (over the same film in conventional B&W chemistry)
via dye amplification -- and the bleach step that's necessary anyway to
remove the silver from the dye image will remove the AH silver as well.
I'd just need a C-41 kit that doesn't require 100 F to work, though
color shifts aren't of concern for B&W; it might be sufficient just to
compensate the color dev time for normal contrast.

I'd have to go back to the data page to verify,
but I've already pretty much decided against the Fomapan after learning
I could still get the Kodak emulsions in either 16 mm single perf or
Double 8.


Isn't Fomapan cheaper and more available?

The last time this came up, someone (who, IIRC, had purchased it direct
from Kodak) said the Kodak stock was cheaper per foot (though it was
only available in something like 200 foot rolls, and only in 16 mm
single perf, as opposed to 25 feet of Double 8). That's a lot of film
for one guy with three working Minolta 16 format cameras and four
cassettes. But even J and C Photography can't seem to verify that
Fomapan R can be developed to a negative -- I asked them about it a
couple months ago, got an answer suggesting use of E-6 bleach, and when
I asked how to avoid bleaching the image as well as the AH layer, never
got a reply (they were waiting for information from Foma, and seemingly
never got it). The E-6 bleach would be perfect for reversal processing
-- but not much use if you want a negative.

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

On Mon, 20 Sep 2004 00:40:48 GMT, Donald Qualls
wrote:

Robert Vervoordt wrote:
On Fri, 17 Sep 2004 17:38:37 GMT, Donald Qualls
wrote:

For use in my subminiature cameras, having a film that's already in 16
mm width is worth a lot compared to slitting, but my current system for
developing that film has limitations, too; some upgrades are in order
before I undertake a process that involves more than 3-4 baths. Film is
held in the homebuilt tank by masking tape, and the tape sometimes lets
go (based on development, generally after fixing but before completion
of wetting agent treatment); that can cause damage, of course. A film I
can develop directly as a negative is good, and one that doesn't require
anything more exotic than Caffenol LC or a high dilution of HC-110 is
more welcome than needing to mix thiocyanate into the developer


Any reversal film can be developed as a negative. In point of fact.
all reversal films are developed as negatives, before they are
*reversed*.

Surely, but with Fomapan R, the negative is impossible to see because of
the (not yet removed) silver AH layer. If I develop Fomapan R in, say,
HC-110 Dilution B, I'll get a solid black strip of film.

Oooh, nasty! That Is quite a bit different from all the other BW
reversal films I encountered or heard of.

In a reversal
process, the bleach step would remove that layer. I'm unclear on what
you're saying happens in the developer (or first dev, for reversal).

I got that wrong, alright. Still, if the AH layer is very fine
colloidal Silver, it might be capable of removal during development in
a normal negative developer with some small amount of Thiocyanate
added. Such layers are "usually" susceptable to quick dissolution by
Thiocyanate long before it would attack any Silver Halides or even
developed Silver grains. A quick test would reveal if that were so.

More on that question below.

; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?),


No, as a method of clearing extremely fine Silver from the highlights.
This is only a consideration for reversal processing and the nead for
very clear highlights in projection. When it comes to negatives and
printing, the slight density in the highlights may be actually an
advantage as it would limit the range of negative densities slightly.

Okay, fine silver in the highlights (after reversal) *is* fog, is it
not?

No. it's not fog. it's much more severe. As experienced by you, with
Fomapan R it's a completely developed layer of colloidal Silver, and
not something an anti foggant would be likely to have any significant
effect upon.

It's a high Dmin in a film that ought to have a very low Dmin;
that sounds like fog to me.

See above.

but the Kodak emulsions
don't require special handling to develop as negatives,


Neither do the others. they are all very much the same animals.

No, anything with a silver AH layer requires *something* different from
conventional B&W development to produce any kind of usable negative,
because the AH layer won't wash out the way antihalation dyes do in
conventional negative films (we often see them as purple or pink color
in the used developer).

and further are
reported to give more speed as negatives compared to Kodak's recommended
low-contrast reversal process for movie film -- the Tri-X Reversal at or
close to the 320-400 range of ordinary Tri-X, and the Plus-X Reversal at
100-125.


No, no no! That's all wrong. The emulsion that is called Tri-X
Reversal is actually Plus-X Negative at its core. Since reversal
processing gives about a stop and a third more effective speed, along
with finer grain in the final image, Kodak can get away with the
renaming. Actually, leaving aside the confusion the renaming causes
when going into the considerations we are discussing, it serves a
purpose in use as the similarly named films are suited for similar
uses.

I listed this before, but here it is again:

Panatomic-X, XT-Pan, Background-X = Plus-X Reversal
Plus-X Pan, Plus-X Negative. = Tri-X Reversal
Tri-X Pan, Double-X Negative = Four-X Reversal

Now, check out the speeds.

Pan-X 25, Plus-X Rev 80
Plus-X Neg 80, Tri-X Rev 200
Double X neg 200, Four-X Rev 400

In effect, using any negative emulsion in a reversal process will
generate an effective sp0eed increase for exposure considerations.

Okay, I never saw that list before, but it was my understanding that
(for instance) Plus-X Reversal was pretty much the same as Plus-X Neg
and Plus-X Pan still photo emulsion, but movie films were expected to be
processed to much lower contrast, which lowers speed.

Yep. That's why the Tri-X emulsion, which is named Double-X Negative
in motion picture use, is rated at 200 or 250 in daylight. Ilford has
or had a Mark 5, which was the same as HP-5. I used both in still
camera work and found them to be the same as the still versions when
developed as suc.

I have heard
previously about speed increases with reversal processing of B&W
negative films like Panatomic X (EI 80 for reversal, 25 for negatives).
I didn't realize that the confusion with speeds and names in Kodak
movie stock was due to Kodak renaming the same emulsion just because of
the speed increase -- but what I'm hearing is that if I buy Tri-X
Reversal, and process it as negative film, I'll get something more like
Plus-X Pan than like Tri-X Pan,

That's right

and if I want/need EI 400 for a
subminiature camera, I'm stuck slitting 400TX or TMY (or similar Ilford
or Agfa products); none of the existing movie stocks will give EI above
200 in D-76.

Four-X reversal is actually the same as Tri-x or Double-X negative.
If developed as you would Tri-X Pan, it will have the same speed and
image chacteristics.
..
Or does the above equivalence of Tri-X Pan with Double-X
Negative movie film suggest that the Double-X Neg is subject to speed
reduction by the low contrast movie negative development, and just gets
back to Tri-X speed with the "boost" of reversal?

Not exactly, Double-X or Tri-X will get to the speed of Four-X
reversal with reversal processing. When processed as a still
negative, the extra processing time will boost speed and contrast over
the results obtained in the motion picture formulae's time and temp,
as well as its different formulation.

This is all very confusing, and none of it would be necessary if I could
just buy ISO 400 B&W negative film in 16 mm (preferably Tri-X Pan, aka
400TX, which gives a very usable EI 1600 without much if any grain
increase when developed in Diafine).

Get some 16mm Double-X and treat it the same as your still fim, tri-X,
and all will be as you desire.


The main original attraction of the Fomapan R was the $8 price for a 25
foot roll in Double 8 format (directly usable in 10x14 mm subminiature
cameras); if I have to go through a bunch of rigamarole to get a
negative from it,


You don't. Just use it as the slower negative it is, no matter what
name the maufacturer uses for it. The principles apply whether it's
Kodak, Foma, color or monochrome.

I do; at a minimum, I have to add thiocyanate to my developer to
dissolve the AH silver. And if I have to give up a stop or more from
the rated EI 100 as reversal film, giving EI 50 or even 32 as negative,
I'm better of with the EI 100 I'm already getting from Copex Rapid
(probably with finer grain as well), without any developer shenanigans
other than diluting HC-110 a lot or diluting Bath A of Diafine by 1:50.

Sounds like Copex Rapid is a better choice, then.


I could have misremembered the Fomapan R process -- specifically, the
first developer might in fact contain an admixture of thiocyanate or
other bleaching agent.


Keep working on getting this straight. The /Thiocyanate is a Silver
solvent, not a bleach. It is used in the developer. The leaching

I meant "bleaching". My typo.

agent is different and used in the bleach, not the developer, of a
reversal process.

Okay, clarify this for me -- if something dissolves metallic silver, to
me, that's a bleach; it'll dissolve image silver and latent image specks
just as readily as it will remove a silver AH layer. As a result, it
seems it ought to eat up shadows in a negative and reduce speed, both by
killing the weakest/sparsest latent image specks before they can be
developed, and by dissolving away the least dense areas of the image
just as it dissolves the AH silver.

The AH Silver is of a different form than the Silver that forms the
image. It is already reduced, and blackened. That is how it works as
an AH layer during exposure. The Thiocyante can attack it
immediately, as it is much more finely formed than any Halide or
Silver grain that will form the image. If this were not the case, it
wouldn't work the way it does in a reversal process.

Silver is silver -- chemically, if you dissolve silver metal one place,
you'll dissolve it anywhere else in the same bath, and dissolving silver
*has to* cost you shadow speed in the negative.

No, it would do that in a reversal developer, as well, if that were
so. You can safely assume that since it works in a reversal first
developer, it can work in a negative developer in the same fashio.
While there are differences in the energy of reversal and negative
developers, they are not enough to make much difference. I did it and
it worked with something I used.

If, OTOH, I develop in C-41 with added black dye coupler, I'm likely to
see a speed increase (over the same film in conventional B&W chemistry)
via dye amplification -- and the bleach step that's necessary anyway to
remove the silver from the dye image will remove the AH silver as well.

Makes sense, if there is significant Dye amplification.

I'd just need a C-41 kit that doesn't require 100 F to work, though
color shifts aren't of concern for B&W; it might be sufficient just to
compensate the color dev time for normal contrast.

Good to know if it works out.

I'd have to go back to the data page to verify,
but I've already pretty much decided against the Fomapan after learning
I could still get the Kodak emulsions in either 16 mm single perf or
Double 8.


Isn't Fomapan cheaper and more available?

The last time this came up, someone (who, IIRC, had purchased it direct
from Kodak) said the Kodak stock was cheaper per foot (though it was
only available in something like 200 foot rolls, and only in 16 mm
single perf, as opposed to 25 feet of Double 8).

Single perf won't work?

That's a lot of film
for one guy with three working Minolta 16 format cameras and four
cassettes.

I see your point.

But even J and C Photography can't seem to verify that
Fomapan R can be developed to a negative -- I asked them about it a
couple months ago, got an answer suggesting use of E-6 bleach, and when
I asked how to avoid bleaching the image as well as the AH layer, never
got a reply (they were waiting for information from Foma, and seemingly
never got it). The E-6 bleach would be perfect for reversal processing
-- but not much use if you want a negative.

I know that you're up to the experiment, just sacrifice a roll or two
and see if it suits you. Thiocyante should be easy to obtain.

I'm smiling just thinking of the commotion at Foma hunting down the
one guy who can answer your questions.



Robert Vervoordt, MFA

Robert Vervoordt wrote:

On Mon, 20 Sep 2004 00:40:48 GMT, Donald Qualls
wrote:

Surely, but with Fomapan R, the negative is impossible to see because of
the (not yet removed) silver AH layer. If I develop Fomapan R in, say,
HC-110 Dilution B, I'll get a solid black strip of film.


Oooh, nasty! That Is quite a bit different from all the other BW
reversal films I encountered or heard of.

Exactly. Fomapan R is a dedicated movie stock, completely unrelated to
Foma's still film emulsions, AFAIK. Silver AH is apparently common in
color movie stocks that will be bleached in processing, but Fomapan is
the only B&W stock I've heard of that has it.

In a reversal
process, the bleach step would remove that layer. I'm unclear on what
you're saying happens in the developer (or first dev, for reversal).


I got that wrong, alright. Still, if the AH layer is very fine
colloidal Silver, it might be capable of removal during development in
a normal negative developer with some small amount of Thiocyanate
added. Such layers are "usually" susceptable to quick dissolution by
Thiocyanate long before it would attack any Silver Halides or even
developed Silver grains. A quick test would reveal if that were so.

Yeah. "Might be."

As you say, a quick test would show this, though I'd be tempted to try
judicious overfixing first; I've acheived visible bleaching using rapid
fixer with additional acetic acid added (though it took a long soak),
and would expect to get results on a silver AH layer more quickly.

More on that question below.


; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?),


No, as a method of clearing extremely fine Silver from the highlights.
This is only a consideration for reversal processing and the nead for
very clear highlights in projection. When it comes to negatives and
printing, the slight density in the highlights may be actually an
advantage as it would limit the range of negative densities slightly.

Okay, fine silver in the highlights (after reversal) *is* fog, is it
not?


No. it's not fog. it's much more severe. As experienced by you, with
Fomapan R it's a completely developed layer of colloidal Silver, and
not something an anti foggant would be likely to have any significant
effect upon.

Okay, like very severe fog, then -- somwhere, if I didn't toss it when
packing for my move, I have a roll of old Kodachrome II (expiry 1964)
that I found in a camera and developed in Diafine; it came out solid
black, but I was able to bleach in acidified rapid fixer (see above)
enough to verify that there were no salvageable images on the film. I
don't think that film had a silver AH layer, though.


Okay, I never saw that list before, but it was my understanding that
(for instance) Plus-X Reversal was pretty much the same as Plus-X Neg
and Plus-X Pan still photo emulsion, but movie films were expected to be
processed to much lower contrast, which lowers speed.


Yep. That's why the Tri-X emulsion, which is named Double-X Negative
in motion picture use, is rated at 200 or 250 in daylight. Ilford has
or had a Mark 5, which was the same as HP-5. I used both in still
camera work and found them to be the same as the still versions when
developed as suc.

I've seen pictures shot with Double-X Negative in 35 mm, they're much
grainier than Tri-X and were shot at EI 200 -- and no, this is not Super
XX from the 1950s, it was 35 mm movie stock bulk loaded into cassettes.
I don't think Double-X Negative is quite the same as Tri-X.

and if I want/need EI 400 for a
subminiature camera, I'm stuck slitting 400TX or TMY (or similar Ilford
or Agfa products); none of the existing movie stocks will give EI above
200 in D-76.


Four-X reversal is actually the same as Tri-x or Double-X negative.
If developed as you would Tri-X Pan, it will have the same speed and
image chacteristics.

Unfortunately, Four-X Reversal isn't available in 16 mm, as far as I've
been able to tell; it might not be available at all any more. I can get
Double-X Negative, I think, which you're saying is the same stuff (but
if it's the same, why doesn't Kodak simply recommend different EI for
shooting as negative or positive instead of marketing as two different
films?).

.
Or does the above equivalence of Tri-X Pan with Double-X

Negative movie film suggest that the Double-X Neg is subject to speed
reduction by the low contrast movie negative development, and just gets
back to Tri-X speed with the "boost" of reversal?


Not exactly, Double-X or Tri-X will get to the speed of Four-X
reversal with reversal processing. When processed as a still
negative, the extra processing time will boost speed and contrast over
the results obtained in the motion picture formulae's time and temp,
as well as its different formulation.

Okay, so Tri-X Pan still film is the same as Four-X Reversal? Then the
Tri-X (ISO 400) gets downrated to EI 200 for movie negative processing
due to lower contrast development, and uprated back to EI 400 for
reversal -- doesn't sound like I'm getting a speed boost with reversal,
just getting back what the movie process loses (unless I'd get another
stop with processing as a reversed still).

This is all very confusing, and none of it would be necessary if I could
just buy ISO 400 B&W negative film in 16 mm (preferably Tri-X Pan, aka
400TX, which gives a very usable EI 1600 without much if any grain
increase when developed in Diafine).


Get some 16mm Double-X and treat it the same as your still fim, tri-X,
and all will be as you desire.

Okay, I might have to see if I can't land a roll of that stuff. It was,
IIRC, around $25 for 200 feet, which is quite attractive (other than the
daunting prospect of having 99 rolls left over if I don't like it).
Won't be money for experimentation for a while, though; this move just
keeps sucking up more and more money...

Okay, clarify this for me -- if something dissolves metallic silver, to
me, that's a bleach; it'll dissolve image silver and latent image specks
just as readily as it will remove a silver AH layer. As a result, it
seems it ought to eat up shadows in a negative and reduce speed, both by
killing the weakest/sparsest latent image specks before they can be
developed, and by dissolving away the least dense areas of the image
just as it dissolves the AH silver.


The AH Silver is of a different form than the Silver that forms the
image. It is already reduced, and blackened. That is how it works as
an AH layer during exposure. The Thiocyante can attack it
immediately, as it is much more finely formed than any Halide or
Silver grain that will form the image. If this were not the case, it
wouldn't work the way it does in a reversal process.

Developed image silver is reduced, as is the metallic silver that forms
a latent image speck -- and I'd argue that a latent image speck, a tiny
fraction of a halide grain, is smaller than the particles of colloidal
silver in the AH layer. In a reversal process, the bleach step that
removes the silver image (either from the first dev, or from both dev
steps, depending on whether you're using a silver-based B&W or a dye
based color film) also removes the AH layer.

From my reading on reversing conventional B&W still films, thiocyanate,
thiosulfate, etc. in the first dev is to remove "stubborn" halide
(undevelopable even after maximum exposure) from the most exposed areas
to prevent fogged highlights after reversal exposure and redevelopment.
This is not at all the same as bleaching away the metallic silver of
the AH layer. A "silver solvent", at least as the term is usually used
relative to development, is a halide solvent, not a metallic silver
solvent; sulfite, thiosulfate, etc. are silver solvents, and their
intended function (at least in that regard, since sulfite does so many
other things) is generally reduction of grain by reducing halide grain
size and preventing excessive growth of silver grains. Thiocyanate,
IIRC, is a true bleach similar to ferricyanides, dichromates,
permanganates, etc.; that is, it is capable of reacting with and
dissolving or rehalogentating reduced silver.

Silver is silver -- chemically, if you dissolve silver metal one place,
you'll dissolve it anywhere else in the same bath, and dissolving silver
*has to* cost you shadow speed in the negative.


No, it would do that in a reversal developer, as well, if that were
so. You can safely assume that since it works in a reversal first
developer, it can work in a negative developer in the same fashio.
While there are differences in the energy of reversal and negative
developers, they are not enough to make much difference. I did it and
it worked with something I used.

What film have you developed with a thiocyanate-added B&W developer that
had a silver AH layer? What developer did you use, and how much
thiocyanate did you add? Knowing this could save me many hours of
experimentation...

Single perf won't work?

Single perf works fine (the Minolta 16 advance system doesn't care about
perforations; it will use single, double, or unperfed, though the later
12x17 frame MGs and QT require single perf loaded with the perforations
toward the cassette bridge, or unperfed, to avoid perforations intruding
on image area).

However, a film sold for Double 8 (double perf, finer pitch perforation
than 16 mm single perf) typically comes in short camera rolls (25 feet,
which is shot, reloaded from the other end, and shot again, then split
after development and spliced to yield 50 feet of 8 mm film) compared to
the 16 mm that comes in 100 or 200 foot lengths.

But even J and C Photography can't seem to verify that
Fomapan R can be developed to a negative -- I asked them about it a
couple months ago, got an answer suggesting use of E-6 bleach, and when
I asked how to avoid bleaching the image as well as the AH layer, never
got a reply (they were waiting for information from Foma, and seemingly
never got it). The E-6 bleach would be perfect for reversal processing
-- but not much use if you want a negative.


I know that you're up to the experiment, just sacrifice a roll or two
and see if it suits you. Thiocyante should be easy to obtain.

When I have time, space, and money to experiment again, I'll probably do
just that; as you say, I can get thiocyanate from Photographer's
Formulary, and $8 (plus shipping, but I'd probably piggyback that with
an order for Classic 400 in 120, which I've been meaning to get anyway)
will get me enough film for a dozen rolls, should be plenty to
experiment on.

I'm smiling just thinking of the commotion at Foma hunting down the
one guy who can answer your questions.

Yeah, which is silly given that they have miles of the film around, and
a warehouse full of chemicals; they should be able to simply shoot a
short length and process it to verify.

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

Robert Vervoordt wrote:

On Mon, 20 Sep 2004 00:40:48 GMT, Donald Qualls
wrote:

Surely, but with Fomapan R, the negative is impossible to see because of
the (not yet removed) silver AH layer. If I develop Fomapan R in, say,
HC-110 Dilution B, I'll get a solid black strip of film.


Oooh, nasty! That Is quite a bit different from all the other BW
reversal films I encountered or heard of.

Exactly. Fomapan R is a dedicated movie stock, completely unrelated to
Foma's still film emulsions, AFAIK. Silver AH is apparently common in
color movie stocks that will be bleached in processing, but Fomapan is
the only B&W stock I've heard of that has it.

In a reversal
process, the bleach step would remove that layer. I'm unclear on what
you're saying happens in the developer (or first dev, for reversal).


I got that wrong, alright. Still, if the AH layer is very fine
colloidal Silver, it might be capable of removal during development in
a normal negative developer with some small amount of Thiocyanate
added. Such layers are "usually" susceptable to quick dissolution by
Thiocyanate long before it would attack any Silver Halides or even
developed Silver grains. A quick test would reveal if that were so.

Yeah. "Might be."

As you say, a quick test would show this, though I'd be tempted to try
judicious overfixing first; I've acheived visible bleaching using rapid
fixer with additional acetic acid added (though it took a long soak),
and would expect to get results on a silver AH layer more quickly.

More on that question below.


; the
thiocyanate (or similar) sounds necessary to reversal processing of any
film (as a fog control for the final positive?),


No, as a method of clearing extremely fine Silver from the highlights.
This is only a consideration for reversal processing and the nead for
very clear highlights in projection. When it comes to negatives and
printing, the slight density in the highlights may be actually an
advantage as it would limit the range of negative densities slightly.

Okay, fine silver in the highlights (after reversal) *is* fog, is it
not?


No. it's not fog. it's much more severe. As experienced by you, with
Fomapan R it's a completely developed layer of colloidal Silver, and
not something an anti foggant would be likely to have any significant
effect upon.

Okay, like very severe fog, then -- somwhere, if I didn't toss it when
packing for my move, I have a roll of old Kodachrome II (expiry 1964)
that I found in a camera and developed in Diafine; it came out solid
black, but I was able to bleach in acidified rapid fixer (see above)
enough to verify that there were no salvageable images on the film. I
don't think that film had a silver AH layer, though.


Okay, I never saw that list before, but it was my understanding that
(for instance) Plus-X Reversal was pretty much the same as Plus-X Neg
and Plus-X Pan still photo emulsion, but movie films were expected to be
processed to much lower contrast, which lowers speed.


Yep. That's why the Tri-X emulsion, which is named Double-X Negative
in motion picture use, is rated at 200 or 250 in daylight. Ilford has
or had a Mark 5, which was the same as HP-5. I used both in still
camera work and found them to be the same as the still versions when
developed as suc.

I've seen pictures shot with Double-X Negative in 35 mm, they're much
grainier than Tri-X and were shot at EI 200 -- and no, this is not Super
XX from the 1950s, it was 35 mm movie stock bulk loaded into cassettes.
I don't think Double-X Negative is quite the same as Tri-X.

and if I want/need EI 400 for a
subminiature camera, I'm stuck slitting 400TX or TMY (or similar Ilford
or Agfa products); none of the existing movie stocks will give EI above
200 in D-76.


Four-X reversal is actually the same as Tri-x or Double-X negative.
If developed as you would Tri-X Pan, it will have the same speed and
image chacteristics.

Unfortunately, Four-X Reversal isn't available in 16 mm, as far as I've
been able to tell; it might not be available at all any more. I can get
Double-X Negative, I think, which you're saying is the same stuff (but
if it's the same, why doesn't Kodak simply recommend different EI for
shooting as negative or positive instead of marketing as two different
films?).

.
Or does the above equivalence of Tri-X Pan with Double-X

Negative movie film suggest that the Double-X Neg is subject to speed
reduction by the low contrast movie negative development, and just gets
back to Tri-X speed with the "boost" of reversal?


Not exactly, Double-X or Tri-X will get to the speed of Four-X
reversal with reversal processing. When processed as a still
negative, the extra processing time will boost speed and contrast over
the results obtained in the motion picture formulae's time and temp,
as well as its different formulation.

Okay, so Tri-X Pan still film is the same as Four-X Reversal? Then the
Tri-X (ISO 400) gets downrated to EI 200 for movie negative processing
due to lower contrast development, and uprated back to EI 400 for
reversal -- doesn't sound like I'm getting a speed boost with reversal,
just getting back what the movie process loses (unless I'd get another
stop with processing as a reversed still).

This is all very confusing, and none of it would be necessary if I could
just buy ISO 400 B&W negative film in 16 mm (preferably Tri-X Pan, aka
400TX, which gives a very usable EI 1600 without much if any grain
increase when developed in Diafine).


Get some 16mm Double-X and treat it the same as your still fim, tri-X,
and all will be as you desire.

Okay, I might have to see if I can't land a roll of that stuff. It was,
IIRC, around $25 for 200 feet, which is quite attractive (other than the
daunting prospect of having 99 rolls left over if I don't like it).
Won't be money for experimentation for a while, though; this move just
keeps sucking up more and more money...

Okay, clarify this for me -- if something dissolves metallic silver, to
me, that's a bleach; it'll dissolve image silver and latent image specks
just as readily as it will remove a silver AH layer. As a result, it
seems it ought to eat up shadows in a negative and reduce speed, both by
killing the weakest/sparsest latent image specks before they can be
developed, and by dissolving away the least dense areas of the image
just as it dissolves the AH silver.


The AH Silver is of a different form than the Silver that forms the
image. It is already reduced, and blackened. That is how it works as
an AH layer during exposure. The Thiocyante can attack it
immediately, as it is much more finely formed than any Halide or
Silver grain that will form the image. If this were not the case, it
wouldn't work the way it does in a reversal process.

Developed image silver is reduced, as is the metallic silver that forms
a latent image speck -- and I'd argue that a latent image speck, a tiny
fraction of a halide grain, is smaller than the particles of colloidal
silver in the AH layer. In a reversal process, the bleach step that
removes the silver image (either from the first dev, or from both dev
steps, depending on whether you're using a silver-based B&W or a dye
based color film) also removes the AH layer.

From my reading on reversing conventional B&W still films, thiocyanate,
thiosulfate, etc. in the first dev is to remove "stubborn" halide
(undevelopable even after maximum exposure) from the most exposed areas
to prevent fogged highlights after reversal exposure and redevelopment.
This is not at all the same as bleaching away the metallic silver of
the AH layer. A "silver solvent", at least as the term is usually used
relative to development, is a halide solvent, not a metallic silver
solvent; sulfite, thiosulfate, etc. are silver solvents, and their
intended function (at least in that regard, since sulfite does so many
other things) is generally reduction of grain by reducing halide grain
size and preventing excessive growth of silver grains. Thiocyanate,
IIRC, is a true bleach similar to ferricyanides, dichromates,
permanganates, etc.; that is, it is capable of reacting with and
dissolving or rehalogentating reduced silver.

Silver is silver -- chemically, if you dissolve silver metal one place,
you'll dissolve it anywhere else in the same bath, and dissolving silver
*has to* cost you shadow speed in the negative.


No, it would do that in a reversal developer, as well, if that were
so. You can safely assume that since it works in a reversal first
developer, it can work in a negative developer in the same fashio.
While there are differences in the energy of reversal and negative
developers, they are not enough to make much difference. I did it and
it worked with something I used.

What film have you developed with a thiocyanate-added B&W developer that
had a silver AH layer? What developer did you use, and how much
thiocyanate did you add? Knowing this could save me many hours of
experimentation...

Single perf won't work?

Single perf works fine (the Minolta 16 advance system doesn't care about
perforations; it will use single, double, or unperfed, though the later
12x17 frame MGs and QT require single perf loaded with the perforations
toward the cassette bridge, or unperfed, to avoid perforations intruding
on image area).

However, a film sold for Double 8 (double perf, finer pitch perforation
than 16 mm single perf) typically comes in short camera rolls (25 feet,
which is shot, reloaded from the other end, and shot again, then split
after development and spliced to yield 50 feet of 8 mm film) compared to
the 16 mm that comes in 100 or 200 foot lengths.

But even J and C Photography can't seem to verify that
Fomapan R can be developed to a negative -- I asked them about it a
couple months ago, got an answer suggesting use of E-6 bleach, and when
I asked how to avoid bleaching the image as well as the AH layer, never
got a reply (they were waiting for information from Foma, and seemingly
never got it). The E-6 bleach would be perfect for reversal processing
-- but not much use if you want a negative.


I know that you're up to the experiment, just sacrifice a roll or two
and see if it suits you. Thiocyante should be easy to obtain.

When I have time, space, and money to experiment again, I'll probably do
just that; as you say, I can get thiocyanate from Photographer's
Formulary, and $8 (plus shipping, but I'd probably piggyback that with
an order for Classic 400 in 120, which I've been meaning to get anyway)
will get me enough film for a dozen rolls, should be plenty to
experiment on.

I'm smiling just thinking of the commotion at Foma hunting down the
one guy who can answer your questions.

Yeah, which is silly given that they have miles of the film around, and
a warehouse full of chemicals; they should be able to simply shoot a
short length and process it to verify.

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.