Pyrocat HD, VC papers, light source and contrast

[Leon]

I recently changed my enlarger from a small condenser type using ilford gel filters (behind the lens) to a Devere 504 diffusion with the colour filter head.

Using my old condenser head with pyrocat hd at 1:1:100 gave me nicely developed negs that printed well at between grades 2 and 3 1/2 depending on shooting conditions etc.

I'm now finding that I'm struggling to get the print contrast I want with full magenta filter selected on the new enlarger. I've tried extending film development times from 14 mins (partial stand) to 20 mins and above (partial stand) with no effect, I've increased dilutions (tried 1:2:100, 2:2:100, 2:1:200) but got little contrast extension.

I'm guessing I'm either going to have to give up on pyrocat (shame - it is great when it does what you want it to, and so cheap), maybe try to get a new dedicated VC head for the enlarger, or something else ...

any observations/ advice anyone can give - is there some way to make pyrocat HD more active?

 

[lee]

maybe the lamp in the enlarger or probably the filters are old and need to be changed just guessing. Do I understand you need more contrast?

lee\c

 

[Donald Miller]

A diffusion enlarger will require a negative with a higher density range than a condenser enlarger. You can accomplish that by either developing your film longer or by mixing pyrocat at 2-2-100 rather than 1-1-100

 

[Chris Lee]

Hi Leon,

I think we talked about this briefly when we did the print exchange!

Interesting to see your getting the same results as me with the devere and diffuser head, I too have pushed dev time to 20 mins at 2:2:100 but seem to be getting very little additional contrast and often end up printing at grade 4 - 5.

I found using ilford under lens filters did improve contrast slightly but the built in filters on my 504 were shot!

I have drifted back to Rodinal but always miss the fantastic gradation of tones from pyrocat, but have come to the conclusion the devere with vc papers and pyrocat has it's limitations!

 

[Leon]

so chris, to be clear, you're getting good results now you've gone back to a non staining developer using the colour head? I may have to go back to perceptol then .....

 

[juan]

Sandy posted here or somewhere that he was testing VC papers with staining developers and was finding the need to increase the contrast filtration above what would be needed with a non-staining developer.
juan

 

[Leon]

Sandy posted here or somewhere that he was testing VC papers with staining developers and was finding the need to increase the contrast filtration above what would be needed with a non-staining developer.
juan

that may be so Juan, but, as my original post said, my old set up managed just fine with VC papers and the pyrocat stain, it's the new set up that is the problem. thanks for your comment though.

 

[Eric Rose]

I am using PyroCat-HD with Adox PL100. Sandy recommended to me that I use 2:2:100. I tried some negs at that dilution and also some at 1:1:100. Each has it's merits when it comes to tonal range etc. In either case I have found that I am using about 1.5 grades higher contrast on my enlarger head than I normally would. The whole split grade thing is almost a non issue as it seems the masking does the soft filtration for you right off. So what I am doing is create a test strip with no filters used and look for the first hint of high lights. Then I expose the a new test strip at this exposure and then start the hard filtration testing.

So far so good. I have been very happy with what I have printed so far, but using PyroCat-HD certainly requires a re-think when printing.

BTW I am using a diffusion head, but will be working with a condenser head soon to see what I can get out of this combination. I am suspecting this is the way to go.

 

[Leon]

I think you might be right about the condensor Eric

 

[Eric Rose]

I think you might be right about the condensor Eric

Yes and no. For some images the condenser would be best and for others the diffusion. I have both, in 4x5 ,so can switch back and forth with out having to do major surgery on my enlargers. I don't like to use the below lens filters so am on the hunt for some 6"x6" contrast filters I can put above the neg.

One thing I haven't had time to do yet is some female portraits developed in PyroCat-HD. I suspect that they will have a beautiful creamy look to them. For this type of subject the diffusion enlarger would be best. I think in the long run I will have to decide at the time of exposure which enlarger I will be using and develop accordingly. Geez, yet another thing to make notes about LOL.

I've just ordered another 8 boxes of the ADOX PL100 so will have lots of film to experiment with.

Another thing I will be trying is using Amidol as a paper dev to see if this will allow me to use less magenta filtration thus reducing any chance of blacks blocking up.

 

[noseoil]

If your contrast is that bad, check your paper developer. No amount of filtration will give a good print with depleted, old or bad developer. tim

 

[Eric Rose]

If your contrast is that bad, check your paper developer. No amount of filtration will give a good print with depleted, old or bad developer. tim

I'm not sure if you're referring to my posting but I don't have a problem with contrast. Just working thru some combinations to take things to a higher level. I always use fresh developer for each printing session. If I'm doing a lot of developing I change it midway thru as well. The stuff's cheap so why try and make it stretch. I also use different paper developers for different papers or vary the developer to get just the tonality I want in a print. Quite often I will use a two bath development scheme as well.

 

[Leon]

If your contrast is that bad, check your paper developer. No amount of filtration will give a good print with depleted, old or bad developer. tim

thanks Tim - I'm still using my old faves of Neutol and Tetenal eukobrom - both of which worked fine with the prints from my old enlarger .....

 

[Donald Miller]

I recently changed my enlarger from a small condenser type using ilford gel filters (behind the lens) to a Devere 504 diffusion with the colour filter head.

Using my old condenser head with pyrocat hd at 1:1:100 gave me nicely developed negs that printed well at between grades 2 and 3 1/2 depending on shooting conditions etc.

I'm now finding that I'm struggling to get the print contrast I want with full magenta filter selected on the new enlarger. I've tried extending film development times from 14 mins (partial stand) to 20 mins and above (partial stand) with no effect, I've increased dilutions (tried 1:2:100, 2:2:100, 2:1:200) but got little contrast extension.

I'm guessing I'm either going to have to give up on pyrocat (shame - it is great when it does what you want it to, and so cheap), maybe try to get a new dedicated VC head for the enlarger, or something else ...

any observations/ advice anyone can give - is there some way to make pyrocat HD more active?

I am not sure what film you are using. My developing times (Pyrocat HD 1-1-100) with Adox PL 100 range from 11 minutes to 30 minutes. The eleven minute times are for normal contrast scenes (SBR 7). The 30 minute times are for flat scenes (SBR 5). This is for normal agitation in BTZS type tubes. My times for semi stand would be longer still. This is for printin with a Durst condenser and point light source which will require a negative with less density range (contrast) than a straight condenser enlarger with an opal lamp and certainly a whole lot less than a diffusiion light source.

 

[sanking]

Sandy posted here or somewhere that he was testing VC papers with staining developers and was finding the need to increase the contrast filtration above what would be needed with a non-staining developer.
juan

I am indeed involved in some testing of VC papers with staining developers, though other activities have delayed completing the study. Bottom line is that you can get enough contrast easily with Pyrocat-HD by either increasing time of development, by using a stronger dilution, or by using a higher number filter. The first two preocedures are self-explanatory, but the last is a bit tricky because of the fact that VC papers have a Green sensitive (low contrast) and Blue sensitive (high contrast) layers. As you increase the filter number the magenta is increased to the point where the green layer no longer has any impact on the print. This happens somewhwere between Filter #3 and #4, depnding on which VC filter set you are using. This means, to put it simply, that when using a filter of #4 or higher, the stained negative will give the same results in terms of contrast as a non-stained negative. This fact should be obvious but does not appear to be widely understood. People who do split filter printing, i.e. two different exposures, one with magenta filter for contrast and another with green filter for low contrast, can easily test this concept.

If you use both graded and VC papers the best procedure is to develop for the CI of the graded paper, which should be about .57, and then use the filters with VC papers to get the needed contrast.

Sandy King

 

[john_s]

I recently changed my enlarger from a small condenser type using ilford gel filters (behind the lens) to a Devere 504 diffusion with the colour filter head.

Using my old condenser head with pyrocat hd at 1:1:100 gave me nicely developed negs that printed well at between grades 2 and 3 1/2 depending on shooting conditions etc.

I'm now finding that I'm struggling to get the print contrast I want with full magenta filter selected on the new enlarger. I've tried extending film development times from 14 mins (partial stand) to 20 mins and above (partial stand) with no effect, I've increased dilutions (tried 1:2:100, 2:2:100, 2:1:200) but got little contrast extension.

I'm guessing I'm either going to have to give up on pyrocat (shame - it is great when it does what you want it to, and so cheap), maybe try to get a new dedicated VC head for the enlarger, or something else ...

any observations/ advice anyone can give - is there some way to make pyrocat HD more active?

It seems to me that the comments about stained negs and the different effects with graded and VC papers are not really the main point. You were using a VC setup sucessfully. Now you have a different VC setup that's not working well, with the same negatives as before. It's diffusion rather than condenser, and that will produce some difference, but the other variable, it seems to me, is the colour of the light that you're getting out of the new setup. I use a diffuse VC setup (2 tube cold light) and have no trouble getting good print contrast from a negative that does not look very contrasty done in pyrocat-hd. I would suspect the filters in the new colour head.

 

[gainer]

The incandescent lamps used with most condenser enlargers have lower color temperature than the quartz-halogen lamps used with many diffusion enlargers. One would expect the new one to be capable of at least the same maximum contrast as the old one. If you still have the filters used with the condenser enlarger, try using one of those on the new enlarger with the built in filter set to white.

 

[john_s]

To see how much of the difference between the old and new setups is due to the diffuse light source instead of the condenser one, can you do a contact print using each light source with whatever filtration/setting is needed to make the prints the same contrast?

That would remove the condenser/diffuser issue and just test the light source colour.

 

[dancqu]

...to put it simply, that when using a filter of #4 or higher, the
stained negative will give the same results in terms of contrast
as a non-stained negative.
Sandy King

Coincidentally I've been reading of light source and contrast.
I was sure Ctein's article "Focusing Blues" was in an issue
of Photo Techniques. Not so. Found it in the September
1995 issue of Camera and Darkroom.

Ctein mentions a maximum 3 1/2 grade on Polymax paper
using a Polymax 5+ filter in conjunction with a 2E filtered
light source. Does a Pyrocat processed film stain so that
it might act as a filter?

I understand what you are saying and would expect
no more than some less intensity of light reaching the
paper; stained vs non-stained. Ctein: "... the 2E robs
the paper of so much of it's blue-light response ...".
Perhaps there is blue and then there is blue. Dan

 

[Donald Miller]

Coincidentally I've been reading of light source and contrast.
I was sure Ctein's article "Focusing Blues" was in an issue
of Photo Techniques. Not so. Found it in the September
1995 issue of Camera and Darkroom.

Ctein mentions a maximum 3 1/2 grade on Polymax paper
using a Polymax 5+ filter in conjunction with a 2E filtered
light source. Does a Pyrocat processed film stain so that
it might act as a filter?

I understand what you are saying and would expect
no more than some less intensity of light reaching the
paper; stained vs non-stained. Ctein: "... the 2E robs
the paper of so much of it's blue-light response ...".
Perhaps there is blue and then there is blue. Dan

Interesting question. Having tested pyrocat stained negatives with a densitometer they do exhibit more density range when read through the blue channel of a color densitometer than they do on the visual channel. And this would tend to make a case for those who use blue and green light as the colors of the filters to expose the two emulsions. That leaves me wondering how that would affect those of us who use yellow and magenta as the filter colors. My Saunders and my Durst both use yellow and magenta.

Additionally if one were using blue and green filters, that would mean that the effects of the pyrocat stain would effectively create addtional density to the passage of blue light and that would mean higher contrast. Or so it would seem to me.

 

[gainer]

Magenta, of course, contains both red and blue. VC paper has no red sensitivity, so only the blue part of the light has an effect, and the blue does not always contain UV. A pyrocat-stained negative will show higher contrast in UV than in blue with UV cutoff. A yellow filter reduces visual blue but may not have an effect on UV. If you are using Wratten filters, you can find the pass band info in the CRC Handbook of Chemistry and Physics.

I wrote "Hazards of a Grain Focuser" for Photo Techniques some years ago. I found that the most accurate and consistent focusing was done in white or green light. The chromatic aberration of the eye together with lower sensitivity gave a wider error spread and an average shift from true focus in either red or blue light. The chromatic focus shift of a good enlarging lens is negligible compared to the focus errors cause by using a deep blue filter while focusing.

 

[dancqu]

[QUOTES=Donald Miller;389309]
"Interesting question. Having tested pyrocat stained negatives
with a densitometer they do exhibit more density range when
read through the blue channel of a color densitometer than
they do on the visual channel."

Perhaps I should not say so but it is not at all obvious to me
why that is so. After all does not the total of the visual reading
include all of any blue component? The blue channel does
measure transmission within the blue portion of the
spectrum? To what extent within?

"And this would tend to make a case for those who use blue
and green light as the colors of the filters to expose the two
emulsions. That leaves me wondering how that would affect
those of us who use yellow and magenta as the filter colors.
My Saunders and my Durst both use yellow and magenta."

Ctein's emphasis is on the very deep blue, violet, and UV. He
mentions only in passing the effect on contrast. The problem
is transmission of those very short wave lengths and emulsions
which are quite sensitive to them. And that ties in with his
real concern, quite literally Focusing Blues.

Due to the band pass characteristics of filters and blue
to green response overlap in the emulsion, reduction in light
levels in the very short wave length portion of the spectrum
will produce lower contrast prints. So with the very light
yellow 2 A, or B, or E filters. Focus though is more exact
with no more than one of those

"Additionally if one were using blue and green filters, that
would mean that the effects of the pyrocat stain would
effectively create additional density to the passage of
blue light and that would mean higher contrast. Or so
it would seem to me."

Blue and green filters pass light of those colors. So too
magenta and yellow. Perhaps you are thinking of band
passing and purity of color? It may be the primary
colors are available more narrow band than the
complementary. Dan

 

[sanking]

Ctein mentions a maximum 3 1/2 grade on Polymax paper
using a Polymax 5+ filter in conjunction with a 2E filtered
light source. Does a Pyrocat processed film stain so that
it might act as a filter? Dan

Yes, film processed in Pyrocat, and many staining developers, has a stain that acts like a filter. The color of the Pyrocat stain is almost always brown. In fact, it can look almost neutral in color. However, the color of the stain is a filter that restricts the passage of blue light, effectively increasing the density of the negative, and its DR, *to the blue sensitive high contrast part of a VC emulsion.* However, the stain does not impede the passage of green green light so it has very little effect on the green sensitive part of the VC emulsion. The net effect is that as shoulder density increases less blue (high contrast) light can affect the VC emulsion, while the green sensitive layer remains unaffected. This results in highlight compensation, which can be a good thing when shooting in high contrast situations.


Sandy King

 

[sanking]

[QUOTES=Donald Miller;389309]
"Interesting question. Having tested pyrocat stained negatives
with a densitometer they do exhibit more density range when
read through the blue channel of a color densitometer than
they do on the visual channel."

Perhaps I should not say so but it is not at all obvious to me
why that is so. After all does not the total of the visual reading
include all of any blue component? The blue channel does
measure transmission within the blue portion of the
spectrum? To what extent within?

The total of a Visual reading may or may not include all of the blue. My densitometer uses for its Visual reading a Green filter with a center wavelength of 555 nm, with bandwidth of about 100 nm. The Blue mode uses a blue filter with bandwith of about 50 nm. As you can see, the Blue mode can reach down to 400 nm, or slightly more, whereas the Visual is limited to about 450 nm. This explains in part why readings of stained negatives almost always show a higher reading in Blue Mode than in Visual.

The issue is actually more complicated than that because the difference between Blue and Visual readings is higher with some staining developers than with others. For example, the difference between a Blue and Visual reading is much higher with a PMK or Rollo Pyro negative than it is with a Pyrocat-HD negative. I illustrate this in my article on pyro staining developers at http://unblinkingeye.com/Articles/PCat/pcat.html

Another issue that has to be taken into cosideration is whether or not one is using a UV filter in the enlarger. The stain of most staining developers is highly actinic and greatly impedes the passage of UV light, and most photographic, both graded and VC, are very sensitive to UV light.

Sandy King

 

[Donald Miller]

[QUOTES=Donald Miller;389309]
"Interesting question. Having tested pyrocat stained negatives
with a densitometer they do exhibit more density range when
read through the blue channel of a color densitometer than
they do on the visual channel."

Perhaps I should not say so but it is not at all obvious to me
why that is so. After all does not the total of the visual reading
include all of any blue component? The blue channel does
measure transmission within the blue portion of the
spectrum? To what extent within?

"And this would tend to make a case for those who use blue
and green light as the colors of the filters to expose the two
emulsions. That leaves me wondering how that would affect
those of us who use yellow and magenta as the filter colors.
My Saunders and my Durst both use yellow and magenta."

Ctein's emphasis is on the very deep blue, violet, and UV. He
mentions only in passing the effect on contrast. The problem
is transmission of those very short wave lengths and emulsions
which are quite sensitive to them. And that ties in with his
real concern, quite literally Focusing Blues.

Due to the band pass characteristics of filters and blue
to green response overlap in the emulsion, reduction in light
levels in the very short wave length portion of the spectrum
will produce lower contrast prints. So with the very light
yellow 2 A, or B, or E filters. Focus though is more exact
with no more than one of those

"Additionally if one were using blue and green filters, that
would mean that the effects of the pyrocat stain would
effectively create additional density to the passage of
blue light and that would mean higher contrast. Or so
it would seem to me."

Blue and green filters pass light of those colors. So too
magenta and yellow. Perhaps you are thinking of band
passing and purity of color? It may be the primary
colors are available more narrow band than the
complementary. Dan

I think that Sandy King explained what I was addressing in my comments.