POP/Platinum: Dense Negative or Just Contrasty

[William Marderness]

I have heard that POP/Platinum papers work best with a dense negative (which I a ssume means a zone I density of more than .10). One stop more exposure than norm al is a common suggestion.

I have experimented with negative density and contr ast for POP paper using a step-wedge and real pictures. I found that extra expos ure (beyond .10 for zone I) was not necessary or beneficial. I developed the neg atives to high contrast, N+2 development for conventional paper. A normal exposu re (.10 density for zone I) produced the expected separation of tone for zones I I and III on the step-wedge and in the pictures. (Expected separation means good separation around zone III, and slight separation around zone II). Greater expo sure did not change the rendition of the shadows in the prints, but it did block up the highlights, by placing zones VII and VIII too high on the shoulder (when developing for high contrast).

What I have settled on as normal for POP is s tandard N+2 development, with the film rated to give .10 density at zone I. Thi s is 2/3rd stop LESS exposure than my normal EI for conventional paper, because the N+2 development pushes the EI up 2/3rds stop.

Do negatives for POP/Platinum really require a dense negative or just a high con trast negative? After testing this out, I think that the usual suggestion to giv e 1-stop more exposure when developing for alternative processes is bad advice.

[Mike Kravit]

For printing Platinum/Palladium you want a negative density range of approximately 1.4-1.6 for pure palladium you want to shoot for a NDR of approximately 1.9

Of course you need to tailor your negative to the scene and previsiualization. It is best to make your so that it prints the way you want without using any contrast agent. Contrast agents degrade image quality and create clumpy grain.

I shoot for a density of 2.45 in the brighest non-specular highlights and .5 in the deepest useable shadow areas.

Mike Mike

[William Marderness]

I use a 1.6 range for POP.

[Christian Nze]

hi william

I totally agree with you. I think that I don't need to overexpose to obtain good neg for POP Palladium platinum. I do most of my neg exposing the film at the good iso ( half the normal as I use ABC pyro developer) and I develop for N+1/2. this give me good rich negative which print easily without contrasting agent. when you use only palladium you can develop more. I also try to expose more but I just find it to block my black.

regards

nze christian http://perso.club-internet.fr/cnze

[Carl Weese]

More development than is normal for silver printing is essential, exposure is quite dependent on the film. With Kodak Tri-X sheet film and Ilford FP4-Plus a generous exposure helps shadow separation without hurting the ability to get a long overall scale. With films like HP5- Plus or Bergger BPF200--which have high levels of base fog and an early shoulder to the curve--extra exposure just cuts the available total range of tones and so should be avoided.---Carl

[Charlie Stracl]

I had always heard "a greater density range" not greater density, thus the goal is higher contrast.