Microdol and film speed

Let me see if I heard this right in the "I want a developer" thread.
Someone wrote that Microdol reduces the speed of the film by 30% in
achieving its fine grain properties? That would mean that if I were
shooting Tmax 400 and planned to process in MDX my effective speed on my
spotmeter should be 280??? Why is it then I get a fairly consistent and
well graduated tonal range setting it for 400???

Patrick

"Patrick Thrush" wrote in message
. ..
Let me see if I heard this right in the "I want a developer" thread.
Someone wrote that Microdol reduces the speed of the film by 30% in
achieving its fine grain properties? That would mean that if I were
shooting Tmax 400 and planned to process in MDX my effective speed on my
spotmeter should be 280???

Right.

Why is it then I get a fairly consistent and
well graduated tonal range setting it for 400???

A 30% underexposure is not noticeable unless you are very attentive to
shadow detail.

Patrick Thrush wrote:

Let me see if I heard this right in the "I want a developer" thread.
Someone wrote that Microdol reduces the speed of the film by 30% in
achieving its fine grain properties? That would mean that if I were
shooting Tmax 400 and planned to process in MDX my effective speed on my
spotmeter should be 280??? Why is it then I get a fairly consistent and
well graduated tonal range setting it for 400???

Patrick

That's about right, yes -- 30% reduction is near enough to a half stop
(half the square root of two is about 71%, or 29% reduction). You'll
get nice tones at EI 400, but you're getting there by extending
development, in effect "pushing" the film a half stop to get your mid
tones back where they belong -- and in the process, you're leaving
behind a half stop of shadow detail.

You might not notice that much loss (I'm pretty sure I wouldn't, unless
I was comparing shots of the same subject, same time, same film, in
different developers), but it's there none the less, and you'll find
"overexposing" by half a stop and reducing development to compensate
will give you improved shadow detail -- with the added benefit of
further reducing grain because of the shortened development.

--
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.

In article uB9yc.2363$zz.1527@attbi_s04, says...
Patrick Thrush wrote:

Let me see if I heard this right in the "I want a developer" thread.
Someone wrote that Microdol reduces the speed of the film by 30% in
achieving its fine grain properties? That would mean that if I were
shooting Tmax 400 and planned to process in MDX my effective speed on my
spotmeter should be 280??? Why is it then I get a fairly consistent and
well graduated tonal range setting it for 400???

Patrick

That's about right, yes -- 30% reduction is near enough to a half stop
(half the square root of two is about 71%, or 29% reduction). You'll
get nice tones at EI 400, but you're getting there by extending
development, in effect "pushing" the film a half stop to get your mid
tones back where they belong -- and in the process, you're leaving
behind a half stop of shadow detail.

The devil is in the details... The shadow detail in my shots must be
discernable, as the majority of my work is architectural HABS
documentation. I have noticed loss of detail that has required me to go
back out the next day and recalculate the exposure for the shadow, often
blowing out highlight detail. Dodging and burning contact work is a
pain in the backside.

On thinking it over, the average shots probably owe their balanced
tonality to the fact that I generally overexpose by one-third stop to
correct for bellows loss and filter variability. This filter situation
can get rather complicated depending on whether a conventional film such
at Tri-X/Plus-X or a TMax is used. The TMax can result in an almost
full stop difference from what is metered through the filter and what
the film produces when using a red filter for masonry detail. Then add
the necessary bellows compensation...

You might not notice that much loss (I'm pretty sure I wouldn't, unless
I was comparing shots of the same subject, same time, same film, in
different developers), but it's there none the less, and you'll find
"overexposing" by half a stop and reducing development to compensate
will give you improved shadow detail -- with the added benefit of
further reducing grain because of the shortened development.


If I were to use an HC-110 formulation, or possibly Diafine, would that
not push up the shadow detail at recommended ASA and development times?
I have not used the HC-110 chemistry in a long time, due to the fact
that it is rather unforgiving in temperature variables while processing
a shoot at the end of the day in the field. Any suggestions or
comments?

Patrick

Patrick Thrush wrote:
In article uB9yc.2363$zz.1527@attbi_s04, says...


The devil is in the details... The shadow detail in my shots must be
discernable, as the majority of my work is architectural HABS
documentation. I have noticed loss of detail that has required me to go
back out the next day and recalculate the exposure for the shadow, often
blowing out highlight detail. Dodging and burning contact work is a
pain in the backside.

Oh, my, yes. You need to use a compensating developer, and if grain is
a problem, either change to a slower film or use a larger format. The
compensation will let you expose enough to record good shadow detail,
but will restrain the highlights and prevent them blocking up. Of
course, you could also help some by printing at a softer paper grade
(which reduces the difference between highlight and shadow; it would let
you expose longer to recover the highlight detail in the negative
without the shadows going black on the paper).

On thinking it over, the average shots probably owe their balanced
tonality to the fact that I generally overexpose by one-third stop to
correct for bellows loss and filter variability. This filter situation
can get rather complicated depending on whether a conventional film such
at Tri-X/Plus-X or a TMax is used. The TMax can result in an almost
full stop difference from what is metered through the filter and what
the film produces when using a red filter for masonry detail. Then add
the necessary bellows compensation...

Okay, so you're already, more or less, rating your Tri-X at 320 intead
of 400 -- assuming it's 35 mm or 120 size 400TX, that is, and not 320TXP
in 120 or sheet film sizes which would have you down to 250.

If I were to use an HC-110 formulation, or possibly Diafine, would that
not push up the shadow detail at recommended ASA and development times?
I have not used the HC-110 chemistry in a long time, due to the fact
that it is rather unforgiving in temperature variables while processing
a shoot at the end of the day in the field. Any suggestions or
comments?

Diafine will push the shadows, but even with its strong compensation
might lead to an even worse problem with highlight density; recommended
EI for 400TX in Diafine is 1250 to 1600 (1000 for 320TXP), though the
real shadow speed probably doesn't exceed 800 (640); the remainder of
the high EI is a push, of sorts. HC-110, even in a compensating
dilution (Dilution E or G), won't raise shadow speed much without the
contrast getting out of hand; I shoot microfilm at twice the normal EI
when I develop in HC-110 G, but I'm using it there more to control
contrast in document film than as a speed enhancer; I'm willing to
accept loss of shadow detail for a one stop push in order to get shots
at EI 50 that I'd have to pass up at EI 25 (or likely at EI 100 over EI
50, depending on the film).

What I would suggest is a divided D-76 formula -- it will give you full
speed (if no increase) but will compress the highlights so you can
expose for the shadows and still get a printable negative. The simplest
and "best" one based on my reading puts the metol (and hydroquinone,
though you could leave it out without significantly changing the working
of the developer) into one bath, the borax in the other, and divides the
sulfite between the two. Three minutes in Bath A (with the metol)
followed without a rinse by three minutes in Bath B; don't over-agitate,
especially in B, and you can reuse the A bath for at least 20 films
(equal to 135-36 or 8x10), the B at least ten with no change in
performance -- and almost independent of temperature (65 to 80 F, pretty
much all the same).

--
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.

Have you tried Difine but using borax+sulfite in sol B?
I understand It becomes softer, better for exposing closer to film's real
speed.

Jorge


On 11 jun 2004, you wrote in rec.photo.darkroom:


Diafine will push the shadows, but even with its strong compensation
might lead to an even worse problem with highlight density;
recommended EI for 400TX in Diafine is 1250 to 1600 (1000 for 320TXP),
though the real shadow speed probably doesn't exceed 800 (640); the
remainder of the high EI is a push, of sorts.

Why is it then I get a fairly consistent and
well graduated tonal range setting it for 400???

Kodak production of film alone has at least plus or minus 1/3 of a stop spec.
This means deliverable 400 film can be as slow as about 320 or as fast as about
500.

Although, about 80% of the film produce is slower side rather then faster side
of the aim point.

You really need about $2000 worth of equipment to tell exactly what the true
speed of a film might be.

Larry

Suggestions? You said you were happy with your results so if it ain't
broke...

--
darkroommike

----------
"Patrick Thrush" wrote in message
.. .
In article uB9yc.2363$zz.1527@attbi_s04, says...
Patrick Thrush wrote:

Let me see if I heard this right in the "I want a developer" thread.
Someone wrote that Microdol reduces the speed of the film by 30% in
achieving its fine grain properties? That would mean that if I were
shooting Tmax 400 and planned to process in MDX my effective speed on
my
spotmeter should be 280??? Why is it then I get a fairly consistent
and
well graduated tonal range setting it for 400???

Patrick

That's about right, yes -- 30% reduction is near enough to a half stop
(half the square root of two is about 71%, or 29% reduction). You'll
get nice tones at EI 400, but you're getting there by extending
development, in effect "pushing" the film a half stop to get your mid
tones back where they belong -- and in the process, you're leaving
behind a half stop of shadow detail.

The devil is in the details... The shadow detail in my shots must be
discernable, as the majority of my work is architectural HABS
documentation. I have noticed loss of detail that has required me to go
back out the next day and recalculate the exposure for the shadow, often
blowing out highlight detail. Dodging and burning contact work is a
pain in the backside.

On thinking it over, the average shots probably owe their balanced
tonality to the fact that I generally overexpose by one-third stop to
correct for bellows loss and filter variability. This filter situation
can get rather complicated depending on whether a conventional film such
at Tri-X/Plus-X or a TMax is used. The TMax can result in an almost
full stop difference from what is metered through the filter and what
the film produces when using a red filter for masonry detail. Then add
the necessary bellows compensation...

You might not notice that much loss (I'm pretty sure I wouldn't, unless
I was comparing shots of the same subject, same time, same film, in
different developers), but it's there none the less, and you'll find
"overexposing" by half a stop and reducing development to compensate
will give you improved shadow detail -- with the added benefit of
further reducing grain because of the shortened development.


If I were to use an HC-110 formulation, or possibly Diafine, would that
not push up the shadow detail at recommended ASA and development times?
I have not used the HC-110 chemistry in a long time, due to the fact
that it is rather unforgiving in temperature variables while processing
a shoot at the end of the day in the field. Any suggestions or
comments?

Patrick

In article ,
says...
Suggestions? You said you were happy with your results so if it ain't
broke...


Well, since I have been confronted with the reality that I will never be
emperor of the world, a magic bullit is now my quest...

On the practical side though, there are the economics of time and
production. Much of my 4x5 film is developed in the field to make a
quick visual check of negative balance, and for insuring the correct
perspective corrections were accomplished at the camera level. If the
shadow detail is not properly revealed, or the highlights wash out
detail, I have to reshoot. Sometimes this cannot be determined until
until I print.

HABS and the Library of Congress require all prints in contact on Azo
paper to full archival specs. What may satisfy me may not please them,
or vice versa. Economy of time and process dictates printing four negs
on 8x10 Azo. Some of the contrast loss can be corrected by burning in,
but this only works effectively at the single 4x5 neg/paper level,
assuming that the detail is present in sufficient densities. Most sites
photographed may run 40 to 60 shots (deliverable), and two sets of
prints processed to archival specs. This can be a little too much hand
print correction. So anything I can do at the negative exposure and
processing end to achieve a better balance can save me an 800 mile or
more trip back to a site to reshoot a couple negatives...

Patrick

Patrick Thrush wrote in message ...
Let me see if I heard this right in the "I want a developer" thread.
Someone wrote that Microdol reduces the speed of the film by 30% in
achieving its fine grain properties? That would mean that if I were
shooting Tmax 400 and planned to process in MDX my effective speed on my
spotmeter should be 280??? Why is it then I get a fairly consistent and
well graduated tonal range setting it for 400???

Patrick

Microdol-X, D-25, and Ilford perceptol, when used full strength
lose about 3/4 stop of speed. This is due to the solvent effect of the
sulfite destroying some of the latent image. Given lower
concentrations or shorter application time sulfite actually increases
film speed slightly because it uncovers more development centers in
the crystals. This is why D-76 delivers about maximum speed. The
effect is a complex one and concerns more than the halide solvent
effect of the sulfite.
When these developers are diluted the development time is not
lengthened in proportion to the sulfite content so the effect of the
sulfite is less. At 1:3 all three developers deliver full film speed
but lose their extra-fine-grain property.
The exact amount of loss depends on the film so you should
experiment to see how much you should increase exposure. About
doubling the exposure over that required by the ISO speed will be
close. Negative film has a tremendous overexposure latitude so some
increase will insure good shadow detail with little danger of blowing
out highlights. If you don't need the extra-fine-property of
Microdol-X its better to use another developer. Xtol and D-76 will
deliver full film speed with little increase in grain.

Richard Knoppow
Los Angeles, CA, USA