Dmax through Pictorico for Silver-Gelatin

Daniel Balfour · Oct 25, 2008

A question for those using Pictorico for silver gelatin contact printing. How do you get Dmax (using a VC enlarger for a light source)?

I've been able to get a good Dmax using the light source without filtration, but the resulting prints were very grainy. I was using iLford MG Fb and the enlarger is a Beseler VC67. I'm guessing this uses a tungsten light source. My guess is that too much of the high-contrast emulsion was activated and thus, I tested with reduced filtration (contrast level 0.5 - 1). Problem is, this requires very VERY long exposures: 20-30 minutes.

I'm trying to switch over to Pictorico as I've seen some pretty remarkable prints made using this substrate. In my own work I've used high-gloss transparencies exposed through a translucent white starch paper (far more transparent then Pictorico or Inkpress). The results were good, but required high level diffusion to forgive the grittiness of acetate, and led to loss of sharpness. Pictorico seems more promising in this regard.

Some tips would be helpful.

donbga · Oct 26, 2008

iserious said:
A question for those using Pictorico for silver gelatin contact printing. How do you get Dmax (using a VC enlarger for a light source)?

I've been able to get a good Dmax using the light source without filtration, but the resulting prints were very grainy. I was using iLford MG Fb and the enlarger is a Beseler VC67. I'm guessing this uses a tungsten light source. My guess is that too much of the high-contrast emulsion was activated and thus, I tested with reduced filtration (contrast level 0.5 - 1). Problem is, this requires very VERY long exposures: 20-30 minutes.

I'm trying to switch over to Pictorico as I've seen some pretty remarkable prints made using this substrate.
Some tips would be helpful.

Daniel,

I'm not sure I'm clear about your workflow, but if I understand your post you have been frustrated with grainy prints when using Pictorico OHP with no filtration, - Grade 2.

In my own work I've used high-gloss transparencies exposed through a translucent white starch paper (far more transparent then Pictorico or Inkpress). The results were good, but required high level diffusion to forgive the grittiness of acetate, and led to loss of sharpness. Pictorico seems more promising in this regard.

This is the part that confuses me. What substrate is high-gloss transparencies? You mention that you diffused the light with white starch paper. What is white starch paper?

So fill us in a bit more please.

Don

Daniel Balfour · Oct 26, 2008

Don,

You got the first part -

In an effort to keep exposure times to something tolerable, I had to expose pictorico unfiltered. This resulted in a dmax exposure of 45sec at a wide-open aperture and with the enlarger actually focused. In addition to my inability to achieve *any* texture at all in the 0-9% patches (grey step wedge), the other patches printed very "coarsely". The density buildup was gritty and unpleasing. I assumed that I must've activated the high-contrast emulsion.

In later experimentation i also realized that (with my specific enlarger - Beseler VC-67) focused light at a wide-open aperture produced a "hot spot" right in the center of the baseboard. I diffused the light by blowing out the focus and closed down half a stop on the lens. That seemed to do the trick. I then tested for dmax exposure at a contrast setting of 0.5, but even at 20 minutes I still couldn't hit it. I gave up and continued testing at contrast setting of 1 which successfully got dmax, albeit at 15 minutes!

I was wondering what other people printing on this substrate were doing. Seems kind of odd - I'm not a contact printer by any means, but 15 minutes? woah.. seems like a VERY long exposure. I wanted to know if I should be considering alternative (enlarger) light sources. I say "enlarger" light sources vs. light box because I'd like to have the selection available when using VC papers.

As for contact printing on acetate -

Inkpress transparencies. I forget what the marketing term for them is. There's only one kind. B&H it.

The starch paper is kind of like wax paper. It is used to wrap pastries (or at least that's where I got the idea). It's smooth and has a milky (visual) texture to it. Very similar to white polyester sheets that are used on the face of softboxes, only stiffer, almost tissue-like. I use 2-3 sheets (together) per exposure and that does the job quite nicely. If there's too much diffusion, I can always remove one sheet.

Hope that clears things up. I'd be interested in your opinion on the light source issue.

donbga · Oct 26, 2008

iserious said:
Don,

You got the first part -

In an effort to keep exposure times to something tolerable, I had to expose pictorico unfiltered. This resulted in a dmax exposure of 45sec at a wide-open aperture and with the enlarger actually focused. In addition to my inability to achieve *any* texture at all in the 0-9% patches (grey step wedge), the other patches printed very "coarsely". The density buildup was gritty and unpleasing. I assumed that I must've activated the high-contrast emulsion.

In later experimentation i also realized that (with my specific enlarger - Beseler VC-67) focused light at a wide-open aperture produced a "hot spot" right in the center of the baseboard. I diffused the light by blowing out the focus and closed down half a stop on the lens. That seemed to do the trick. I then tested for dmax exposure at a contrast setting of 0.5, but even at 20 minutes I still couldn't hit it. I gave up and continued testing at contrast setting of 1 which successfully got dmax, albeit at 15 minutes!

I was wondering what other people printing on this substrate were doing. Seems kind of odd - I'm not a contact printer by any means, but 15 minutes? woah.. seems like a VERY long exposure. I wanted to know if I should be considering alternative (enlarger) light sources. I say "enlarger" light sources vs. light box because I'd like to have the selection available when using VC papers.

As for contact printing on acetate -

Inkpress transparencies. I forget what the marketing term for them is. There's only one kind. B&H it.

The starch paper is kind of like wax paper. It is used to wrap pastries (or at least that's where I got the idea). It's smooth and has a milky (visual) texture to it. Very similar to white polyester sheets that are used on the face of softboxes, only stiffer, almost tissue-like. I use 2-3 sheets (together) per exposure and that does the job quite nicely. If there's too much diffusion, I can always remove one sheet.

Hope that clears things up. I'd be interested in your opinion on the light source issue.

Daniel,

I use graded paper not VC, even so I've never been able to get prints without some substrate grain showing when using Pictorico OHP. I've not tried making digi-negs for silver gelatin since I purchsed my Epson 3800 but eventually I'll give it another go.

One thing that works pretty well helping reducing the substrate grain is to use glossy inkjet paper. It works pretty well, with somes images it works very well.

You also need a brighter light source such as a 120 watt flood light suspended from the ceiling. What will also be useful is to use a white light integrator such as a Metrolux timer. Using an integrator will help provide very consistent exposures. Another gizmo that would be helpful is a compensating development timer to insure consistent development of the paper.

Being able to ensure consistent exposure and development goes a long way towards producing a good adjustment curve when printing digital negatives on gelatin silver or other processes for that matter.

Don

menglert · Oct 26, 2008

Try using Pictorico White Film for silver gelatin rather than OHP. Make sure your printer is set to the highest resolution. And as Don said, try using graded papers.

I've been away from this for a while and I'm sorry I can't offer more advice at the moment.

-Martin

David A. Goldfarb · Oct 27, 2008

I've just started experimenting with this using Pictorico Premium OHP with my HP B9180 printer, and I'm not getting very long exposure times--less than 10 sec. typically using my Omega D-II, Arista Hi-D cold light source with a V54 bulb, lens at around f:5.6-8, defocused, projecting a square of light around 11x14" with a 4x5" neg carrier. I'm using Efke Emaks graded mostly, and some MGIV FB.

I am finding the grain issue that you mention, but I think that with the neg that I tried (a 35mm Tech Pan neg scanned on a Dimage Scan Dual I) it's grain aliasing in the scan. I made another enlarged neg from a higher resolution scan (a 4x5" Efke PL100 neg scanned on a Duoscan at 1000 dpi), but I haven't printed it yet. I've tried to make this neg thinner, but with the same density range as my first attempt (i.e., with less "base fog"), and I'm hoping that will keep down the graininess, as it would with a silver neg. I'll report back when I print it.

Daniel Balfour · Oct 27, 2008

David A. Goldfarb said:
I've just started experimenting with this using Pictorico Premium OHP with my HP B9180 printer, and I'm not getting very long exposure times--less than 10 sec.

David,

If I understand correctly, OHP is transparency material (clear acetate) whereas I'm printing on white film which is far more opaque.

David A. Goldfarb · Oct 27, 2008

The film I have is slightly white (just white enough so that the printer recognizes that there is media in the tray), but maybe not as opaque as the film you have.

donbga · Oct 27, 2008

iserious said:
David,

If I understand correctly, OHP is transparency material (clear acetate) whereas I'm printing on white film which is far more opaque.

Okay that clarifies something for me, I thought you are using clear OHP not white film. With the white film and diffusion paper I can see where your times might get quite lengthy.

Did you calculate your minimum printing time with the diffusion paper in place?

Don

Daniel Balfour · Oct 27, 2008

Don,

You misunderstood -

I was printing on OHP-like transparency film (clear) with diffusion paper. I am now experimenting with Pictorico white film (no diffusion paper) as it doesn't require any additional diffusion. This is where I'm getting the super-long exposure times.

I'm going to do a series of tests tonight using a higher contrast level, 2 perhaps. I'll see how that goes and post results.

Don Bryant said:
Okay that clarifies something for me, I thought you are using clear OHP not white film. With the white film and diffusion paper I can see where your times might get quite lengthy.

Did you calculate your minimum printing time with the diffusion paper in place?

Don

David A. Goldfarb · Oct 28, 2008

The thinner neg definitely improved the grain situation.

My exposure times are generally under 3 sec. I have a Metrolux compensating timer with a probe that I can set in increments of 1/10 sec., so I can manage those times accurately.

You can fiddle endlessly with this stuff, can't you? I'm on my fifth neg from the same original, and I'm still not done yet.

Daniel Balfour · Oct 28, 2008

David A. Goldfarb said:
The thinner neg definitely improved the grain situation.

My exposure times are generally under 3 sec. I have a Metrolux compensating timer with a probe that I can set in increments of 1/10 sec., so I can manage those times accurately.

You can fiddle endlessly with this stuff, can't you? I'm on my fifth neg from the same original, and I'm still not done yet.

Yes the experimentation can be virtually limitless. I'm not sure I understand what you mean by "thinner neg". With digital negatives, (ink) density range is established by printing/testing a step wedge to dMax. The DR of the neg is adapted to match the tonal range of the desired paper.

David A. Goldfarb · Oct 28, 2008

Well, at first I was just trying to make a neg that looked liked a good neg, so I might have had a neg that went from, say 55-255, but then I realized that it would make more sense to have a neg going from 0-200, with the same range, but lower overall density--same density range, but a thinner neg.

Now, it seems like in theory the density range of a negative that goes from 0-200 should produce the same result with a shorter exposure time as a neg that goes from 55-255, but it doesn't seem to be true in practice. When I made denser negs with the range going to 255, I found that if I made a good looking image, inverted it, and then adjusted the gamma to 0.6 with curves in Photoshop, I could get a good tonal range in the negative. When I made a thinner neg with the range starting at 0, I found that I had to set the gamma to about 0.9 to have a neg that printed well. Now that's the gamma as it is graphed in Photoshop, not the actual gamma based on transmissive density readings, since I don't have a densitometer at the moment. Maybe that has to do with the short exposure reciprocity characteristics of the paper or the way ink is distributed on the medium or transmissive density as opposed to reflective density. I suspect the curve in Photoshop is based on reflective density, and Photoshop has no idea what the transmissive densities of the inks are.

Daniel Balfour · Oct 28, 2008

David A. Goldfarb said:
Well, at first I was just trying to make a neg that looked liked a good neg, so I might have had a neg that went from, say 55-255, but then I realized that it would make more sense to have a neg going from 0-200, with the same range, but lower overall density--same density range, but a thinner neg.

Here's the confusing part -

I'm not sure I understand what you mean by "making a neg that looked like a good neg". Perhaps we're going about this differently? I follow much of the QTR method (and most other methods in this respect) in that I expose a sheet of photo paper through the printing substrate, in your case OHP, to establish my "base exposure" - minimal exp for dMax.

Hence, I'm not sure what you mean by thinner/thicker negative in this regard. The inks are only relevant after you've exceeded the threshold exposure required to render pure black through OHP.

Unless you're talking about reducing the overall image contrast - but again, that would be an aesthetic consideration, not a technical one. Printing times and ink densities are and should be a constant, determined by a fixed exposure time and resulting step wedge density characteristics.

David A. Goldfarb said:
Now, it seems like in theory the density range of a negative that goes from 0-200 should produce the same result with a shorter exposure time as a neg that goes from 55-255, but it doesn't seem to be true in practice. When I made denser negs with the range going to 255, I found that if I made a good looking image, inverted it, and then adjusted the gamma to 0.6 with curves in Photoshop, I could get a good tonal range in the negative. When I made a thinner neg with the range starting at 0, I found that I had to set the gamma to about 0.9 to have a neg that printed well. Now that's the gamma as it is graphed in Photoshop, not the actual gamma based on transmissive density readings, since I don't have a densitometer at the moment. Maybe that has to do with the short exposure reciprocity characteristics of the paper or the way ink is distributed on the medium or transmissive density as opposed to reflective density. I suspect the curve in Photoshop is based on reflective density, and Photoshop has no idea what the transmissive densities of the inks are.

It sounds to me like you're using the Burkholder method, or some derivative thereof, applying gamma curves inside photoshop directly to your image. While that can certainly enhance visual aesthetic and in Burkholder's case, be used to match the density range of the image (by way of ink deposits) to that of your photo paper, its all independent of base exposure time which should be your single constant.

As for photoshop's "K" values (densities), they are exclusively reflective. Photoshop has, to my knowledge, no use for transmission densities (aka "opacity").

David A. Goldfarb · Oct 28, 2008

I'm not following anyone's method but my own at the moment. I know what a good neg looks like, so for me that's the starting point--to make a neg that looks like a good neg that came from a camera.

I also know that what the paper sees and what I see are different, and that what I'm used to seeing in a silver negative might produce different results with an ink neg, so I need to print and experiment and get a practical sense for the relationship between what I see on the monitor, the curve, what the neg looks like on the light box, and what the print looks like.

The minimum exposure for maximum black approach (as it's called in traditional printing) makes sense if the Dmin of the neg actually has no ink. At first I had started from the other end, so that the image on the neg went from, say, gray to maximum black (a "thicker" neg). Then I realized that this was mistaken, and the image on the neg should go from clear to grey (a "thinner" neg). It only took me one neg to figure this out, so I consider it effort well spent. So now, I think we are using the same approach in that regard.

That said, minimum exposure time for maximum black can be something of a dogma, and given that the paper has reciprocity characteristics, it might be necessary to vary from a constant base exposure time, if the base exposure is very short (as in my case) or very long (as in your case). I'm satisfied with the print I made for the moment, but I think next time, I'll dial down the light, so I can get an exposure time of around 10 sec. instead of 1.4 sec., as was the case with this neg, to avoid any potential reciprocity confusion.

I'm also not entirely sure that the transmissive density of the ink varies in a completely linear way with respect to the reflective density of the ink. Minimum time for maximum black is a good principle for making a proof sheet and finding a starting point, but when it comes down to making a final print, anything is fair game in my book.

Dmax through Pictorico for Silver-Gelatin

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