I need help evaluating C41 processing services

[Mark Muse]

Anyone know of a site or other source of information on C41 processing problems from the perspective of purchasing processing services? I have been using Portra 160 and having it processed locally. I am scanning the negatives and printing on an inkjet. I am not getting the highlight through quarter tone (zone IX-IV) value separation that I want. Also my images could be sharper and I have a bit more grain than I think I should have.

I am overexposing a bit (indexed at 100) to get the shadow values I want but I think this small amount should not, if the processing is correct, create these other problems. I did have a few rolls processed by another lab and things seemed a little improved, though if so it was not dramatic.

If I were making color prints on an enlarger what kind of density would I want for zone VIII?

All of my lenses are modern multicoated and well respected brands/designs. I am using a tripod that exceeds my needs.

Any info and insight appreciated. Thanks.

[Mark Sampson]

Try printing the same negative to the same size the way it was designed to be printed- on RA-4 photographic paper. This will provide a reference standard. The C-41 process is fairly simple. It's far more likely that your problems come from the digital parts of your workflow.

[Mike Lyons]

Mark, I've been having the same problem and was about to post virtually the same question. I print via (diffusion) enlarger on Fuji Crystal Archive RA-4 paper and do not do any scanning. I also down rate the film to ASA 100-125 and have found that consistently my Zone V-VIII values come back from the lab lower than I would like for B&W negs (nett densities of about 0.4-0.7 above f-fb, as opposed to about 0.7-1.3 for b/w) Although the prints are acceptable, I'm also wondering if they would be better on a neg with slightly higher contrast. If someone could help both of us out here with some advice I think we would both appreciate it. Mike

[Mark Sampson]

Here are some more thoughts. 1) C-41 is a robust process, not as finicky as E-6. Your lab should keep their process well-controlled, discuss your issues with them; they are probably willing to help. 2) Shoot an exposure series; normal, +1 stop, +2 stops. Print them all to match, evaluate. Color neg film has almost no underexposure latitude, lots of overexposure latitude. 3) If you are using Kodak Portra 160NC film, try the 160VC film instaed. It is more contrasty and has more saturated colors. 4) try Kodak's Ultra Endura paper; it has the most contrast of their papers. I have never tried Fuji's color paper so have no way to compare- but I'd bet the color rendition would be different, in any case.

[Mark Muse]

Thanks for the ideas.