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Selenium, negative intensifier and curves



 
 
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  #1  
Old November 4th 04, 04:51 AM
Frank Earl
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Default Selenium, negative intensifier and curves

If anyone has already checked this I would appreciate the info. When
using selenium as a negative intensifier, does it change the curve
proportionally or does it change it non-proportionally?

As I understand it(and my experience seems to support this), selenium
toner used to intensify film can get about 1 grade (0.3) of increased
density. When toning paper, selenium seems to affect the darks
proportonally more than the lights. This would lead me to believe that
using it to intensify a negative would affect the highights
proportionally more than the shadows.

Now I can test this by exposing a negative with a step wedge, checking
it on a densitometer, intensifying it and checking it again. But if
anyone has done this, I like to know what you found.

Thanks
  #2  
Old November 4th 04, 11:47 AM
Richard Knoppow
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Default


"Frank Earl" wrote in message
news:5Hhid.31621$SW3.10215@fed1read01...
If anyone has already checked this I would appreciate the
info. When using selenium as a negative intensifier, does
it change the curve proportionally or does it change it
non-proportionally?

As I understand it(and my experience seems to support
this), selenium toner used to intensify film can get about
1 grade (0.3) of increased density. When toning paper,
selenium seems to affect the darks proportonally more than
the lights. This would lead me to believe that using it
to intensify a negative would affect the highights
proportionally more than the shadows.

Now I can test this by exposing a negative with a step
wedge, checking it on a densitometer, intensifying it and
checking it again. But if anyone has done this, I like to
know what you found.

Thanks


I can't answer directly because I've never taken a
densitometer to a selenium intensified negative. However,
the split toning effect of Selenium depends somewhat on its
dilution. The split tones That result in insufficient
protection come from the use of highly diluted toner (1:20)
but becomes less as a more concentrated solution is used. At
1:9 the effect is small enough to provide good overall image
protection. It is more even at higher concentrations and as
toning is carried toward completion.
Selenium toner has some advantages as an intensifier: it
is packaged and it is more controllable and reliable than
most other intensifiers, the image is also permanent, not
true of some other intensifiers.
There are more powerful intensifiers but they tend to be
less predictable. Probably the best of the lot is chromium
intensifier but Selenium is better if it will go far enough.
Silver intensifier is the only one resulting in a neutral
colored image.


--
---
Richard Knoppow
Los Angeles, CA, USA



  #3  
Old November 4th 04, 06:34 PM
Douglas
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Default

"Frank Earl" wrote
If anyone has already checked this I would appreciate the info. When
using selenium as a negative intensifier, does it change the curve
proportionally or does it change it non-proportionally?

As I understand it(and my experience seems to support this), selenium
toner used to intensify film can get about 1 grade (0.3) of increased
density. When toning paper, selenium seems to affect the darks
proportonally more than the lights. This would lead me to believe that
using it to intensify a negative would affect the highights proportionally
more than the shadows.

Now I can test this by exposing a negative with a step wedge, checking it
on a densitometer, intensifying it and checking it again. But if anyone
has done this, I like to know what you found.

Thanks


I've used selenium toner (KRST at 1+3 dilutions) for approx. 5-12 min. to
many intensify negatives (120, 4x5, 8x10). I don't have a densitometer, so I
have no info on your last paragraph. But it did seem to be easily a grade in
paper improvement. It's been a few years now but I used to do this to
increase contrast in the neg when printing on graded papers. With VC papers
I've not been as motivated to selenium intensify. The density increase
effect seemed to me to be directly proportional to the amount of density in
the original neg. I found it to be very similar to longer negative
development time - it gave me a second chance. I preferred it to increasing
the paper contrast grade. It worked quite well and it seemed to be
foolproof. I never ruined a negative nor was I ever really disappointed. I
found that reducing dense negatives (overdeveloped) was not nearly as
successful as being conservatively (a little) short in development time and
then intensifying only if required.

Intensification occurs quite slowly often (depends upon film type) with an
increasing plum or blue colour to the neg. It worked well incrementally i.e.
try a little, dry and contact print, then if not enough repeat. I used to do
it by inspection using two large Pyrex dishes with tungsten lights
projecting through the dishes from below. I would visually compare the
difference for negs in a holding bath of water with those being toned. The
lights also kept the temperature of solutions quite warm which reduced the
time and kept the rate of toning consistent. I recommend good ventilation,
warm KRST in theses dilutions is very smelly and somewhat irritating.

Douglas


  #4  
Old November 5th 04, 11:19 AM
Dan Quinn
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Default

Frank Earl

Search this NG for, slimt adams . Ansel used selenium to
gain one zone. Dan
  #5  
Old November 5th 04, 11:19 AM
Dan Quinn
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Posts: n/a
Default

Frank Earl

Search this NG for, slimt adams . Ansel used selenium to
gain one zone. Dan
  #6  
Old November 5th 04, 03:28 PM
Lloyd Erlick-Usenet
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Default

On Thu, 4 Nov 2004 12:34:43 -0500, "Douglas"
wrote:

... I recommend good ventilation,
warm KRST in theses dilutions is very smelly and somewhat irritating.

Douglas



nov504 from Lloyd Erlick,

A Pyrex baking pan of appropriate dimensions would have
made a nice cover to that excellent setup. A nice smell
reducing cover, that is.

And thanks very much for the detailed observational
record. Intensifying negs with KRST is often talked
about but rarely do we see the intimate details ...

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email:
net:
www.heylloyd.com
________________________________


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  #7  
Old November 5th 04, 03:28 PM
Lloyd Erlick-Usenet
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Posts: n/a
Default

On Thu, 4 Nov 2004 12:34:43 -0500, "Douglas"
wrote:

... I recommend good ventilation,
warm KRST in theses dilutions is very smelly and somewhat irritating.

Douglas



nov504 from Lloyd Erlick,

A Pyrex baking pan of appropriate dimensions would have
made a nice cover to that excellent setup. A nice smell
reducing cover, that is.

And thanks very much for the detailed observational
record. Intensifying negs with KRST is often talked
about but rarely do we see the intimate details ...

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email:
net:
www.heylloyd.com
________________________________


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---
  #8  
Old November 8th 04, 09:15 PM
Tom Phillips
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Posts: n/a
Default



Richard Knoppow wrote:

"Frank Earl" wrote in message
news:5Hhid.31621$SW3.10215@fed1read01...
If anyone has already checked this I would appreciate the
info. When using selenium as a negative intensifier, does
it change the curve proportionally or does it change it
non-proportionally?

As I understand it(and my experience seems to support
this), selenium toner used to intensify film can get about
1 grade (0.3) of increased density. When toning paper,
selenium seems to affect the darks proportonally more than
the lights. This would lead me to believe that using it
to intensify a negative would affect the highights
proportionally more than the shadows.

Now I can test this by exposing a negative with a step
wedge, checking it on a densitometer, intensifying it and
checking it again. But if anyone has done this, I like to
know what you found.


Yes, you can certainly do this and use the data to adjust
your negative development time to obtain a "normal" contrast
range when toning negatives. I don't know why you would want
an arbitary increase in density otherwise obtained through
normal exposure and development, though. But as Richard notes
with selenium you'd need a lower dilution (at least 1:9 or lower)
to avoid split toning. I don't routinely do this using selenium
so I've never drawn curves. I do occasionally intensify a negative,
but it depends strictly on the negative.

For better archival negative toning and more _even_ density I'd
use/experiemtn with a polysulfide toner like Kodak brown toner
not selenium.

Thanks


I can't answer directly because I've never taken a
densitometer to a selenium intensified negative. However,
the split toning effect of Selenium depends somewhat on its
dilution. The split tones That result in insufficient
protection come from the use of highly diluted toner (1:20)
but becomes less as a more concentrated solution is used. At
1:9 the effect is small enough to provide good overall image
protection. It is more even at higher concentrations and as
toning is carried toward completion.


At 1:9 it will affect all densities. Though it will add greater
density to highlight areas, it can add slight but significant
density to shadow areas. It will increase local contrast
accordingly. I think you really need to be careful though
and very sure about using it for the results desired.

As an intensifier, it might be remembered you don't have to
intensify the entire negative, but just those areas where
greater local contrast is desired.

Selenium toner has some advantages as an intensifier: it
is packaged and it is more controllable and reliable than
most other intensifiers, the image is also permanent, not
true of some other intensifiers.
There are more powerful intensifiers but they tend to be
less predictable. Probably the best of the lot is chromium
intensifier but Selenium is better if it will go far enough.
Silver intensifier is the only one resulting in a neutral
colored image.

--
---
Richard Knoppow
Los Angeles, CA, USA

  #9  
Old November 10th 04, 01:14 AM
Dan Quinn
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Posts: n/a
Default

Tom Phillips wrote

I don't know why you would want an arbitary increase in
density otherwise obtained through normal exposure and
development, though.


Probably because some negatives to be printed are not ideal.
I've negatives from the 30s and some of my own from the 60s,
which for sure will need something.
What I'd like to know is if I intensify with selenium will
it work well with generations old negatives. Dan
  #10  
Old November 10th 04, 01:14 AM
Dan Quinn
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Posts: n/a
Default

Tom Phillips wrote

I don't know why you would want an arbitary increase in
density otherwise obtained through normal exposure and
development, though.


Probably because some negatives to be printed are not ideal.
I've negatives from the 30s and some of my own from the 60s,
which for sure will need something.
What I'd like to know is if I intensify with selenium will
it work well with generations old negatives. Dan
 




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