Ilford Direct Positive Paper - diagnosing Dmax problem

[dodphotography]

Having issues here folks...

I have several boxes of 4x5, shot at similar exposures using Sprint Dev (1:9) at 3 mins dev and they are fine, pure black rebates from holder/camera.

Now, a single box of 8x10... sheets are receiving adequate light (overcast, Ilford 8x10 Pinhole (I found a reference to the aperture being F288)) 40 min exposures.

When developed, rebates and overall tonality is grey... using the same developer and trays (and in the same sessions) as the 4x5 which are fine.

Is this a bad batch of paper? Unfortunately I do not have another box to crack and even test.

[richydicky]

I found the same using some developers. What I have learned is that DPP is hungry for developer and depletes it quickly so that times adequate for 4x5 can lead to underdevelopment in 8x10, weak dMax and overall grey. I thought that it may be due lack of volume of developer to cover the 4 times larger area of 8x10, but I had the problem that using rotary tubes I was limited to the amount of solution I could use. I have gotten good results using Dektol (D72 self mixed) using the max solution volume I could in rotary tubes resulting in same times as 4x5.

Richard

[dodphotography]

I found the same using some developers. What I have learned is that DPP is hungry for developer and depletes it quickly so that times adequate for 4x5 can lead to underdevelopment in 8x10, weak dMax and overall grey. I thought that it may be due lack of volume of developer to cover the 4 times larger area of 8x10, but I had the problem that using rotary tubes I was limited to the amount of solution I could use. I have gotten good results using Dektol (D72 self mixed) using the max solution volume I could in rotary tubes resulting in same times as 4x5.

Richard

I mixed up a new batch of developer and the same effect across the 8x10 sheets. Reference seen here, just going off rebates black vs grey.


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[richydicky]

I didn’t have chance to investigate further myself as the summer has been so bad. I had started to develop longer but was still not getting full dMax and concluded that I might need to adjust the concentration with that developer which was a film developer. I am not familiar with Sprint, is that a film or paper developer? I have found best results with paper or universal developers such like PQ. Your exposures look good.

What might be a useful thing to do is to work out the developer concentration you are using with the 4x5 paper, i.e. the volume of developer concentrate per square inch of paper and ensure when you make up the developer solution for 8x10 you are using the same amount of developer per area and adjust overall volume or concentration.

The best way to test is to develop in trays, which I can’t do now without a darkroom, so you can judge when the appropriate development time is reached. You might find just developing more time with the same dilution is OK or need to adjust the concentration. You could expose an 8x10 sheet and cut it into strips to test development by inspection.

Richard

[Michael R]

Is there anything different at all about how you are handling the 8x10 paper before development (loading/unloading holders etc.) or even during processing which might be fogging it?

Are you handling/processing in total darkness or with a deep red safelight? (I know we should expect 8x10 to behave the same as 4x5 if you are doing everything the same but just asking)

I suggest two experiments with your developer - 1) Try doubling development time to see if it makes any difference (no safelight), 2) Try a more concentrated dilution of Sprint, say 1+3 to see if that does anything. These experiments might help you rule out (or in) underdevelopment. Here too, one would expect an 8x10 sheet to develop the same way as 4 4x5 sheets but it can’t hurt to try what I suggest just to see what happens.

Having issues here folks...

I have several boxes of 4x5, shot at similar exposures using Sprint Dev (1:9) at 3 mins dev and they are fine, pure black rebates from holder/camera.

Now, a single box of 8x10... sheets are receiving adequate light (overcast, Ilford 8x10 Pinhole (I found a reference to the aperture being F288)) 40 min exposures.

When developed, rebates and overall tonality is grey... using the same developer and trays (and in the same sessions) as the 4x5 which are fine.

Is this a bad batch of paper? Unfortunately I do not have another box to crack and even test.

[MartinP]

May I suggest that if the usable amount of fresh paper developer is insufficient, that one pours it out and develops a second time using a second volume of fresh paper-developer? The process is cumulative after all.

[dodphotography]

It’s a whole mess of bad product… I have a solid darkroom, huge 18-20 ft ceilings. Safe light has never been an issue with anything, ever.

1.) I handled all the paper the same. Each box of paper was brand new from BH, sealed. It was never left in any extreme weather.

2.) developer is all fresh. When issues arose I started the following test.

Developer blank sheets in three separate trays with fresh developer. 810 sheets from bad box shows a light grey at 3 mins. Sheets from good box of 4x5 turn deep black at the same time.

It then became further complicated. Pulled the last sheet of 45 paper, cracked a new box of 45 and loaded two sheets from that box into 45 holders. Shot in the same camera, same exposures, etc in the time span of 20 seconds.

Developed them… boom, same issue. Last Sheet from the good box is great, two sheets from the new sealed box are crap.




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[Oren Grad]

Can you post the batch numbers from your boxes, good and bad?

[dodphotography]

Will do tomorrow when I’m back in the lab. I have four boxes of 45, one 810, and one 1114. It’s more experimental for students (I run a HS photo program) but at that price I can just shoot sheet film with students.


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[dodphotography]

Good box of 45


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