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View Full Version : Do photoshop curves replace need for self-developing negatives?



altec2
28-Jan-2012, 19:04
Wondering generally if developing your own bw film and being very precise about controlling the variables is worth it if trying to use the zone system...

or is it your opinion that digital processing can do the contrast manipulation part of it easier if you just get "close enough" exposure and development

Second question: if you are going to shoot negative film, the traditional zone system says expose for the darkest area you want good detail (like zone iii) and then you develop for the highlights and contrast. But if you are scanning the negatives, the dense highlights are hard to pick up, so do you flip your approach and expose for the highlights or do you just try to be spot on (or err on the side of underexposure)?

Darin Boville
28-Jan-2012, 19:22
Underdevelop a little and be astonished at how much shadow detail gets picked up by the scanner? Got to rethink your zones, I suppose!

--Darin

Ben Syverson
28-Jan-2012, 19:49
"Expose for the shadows" is advice for the ages. Any scanner should be able to read into the densest highlights on a negative, because the black area of an E6 transparency is much, much denser.

If anything, "expose for the shadows" is even more true today, because Curves lets you restore extremely overexposed highlights in a way that would be unthinkable in the darkroom.

The choice you have now is in which "zone" you're willing to allow more noise & grain. If you need to use extreme Curves to rescue your highlights, they will definitely get noisy. If you use extreme Curves to rescue the shadows, they can block up (hit Dmin) as well as getting noisy. Your choice may depend on the image.

Lenny Eiger
28-Jan-2012, 20:46
Wondering generally if developing your own bw film and being very precise about controlling the variables is worth it if trying to use the zone system...

Second question: if you are going to shoot negative film, the traditional zone system says expose for the darkest area you want good detail (like zone iii) and then you develop for the highlights and contrast.

The answer is No, curves will not replace a good negative.

It is true that you have a little more leeway than if you were using graded paper in the darkroom. My experience is that you can develop a bit longer and use a more spread-out tonal range, similar to what alternative processes can handle. However, many of us here disagree on the density of the perfect neg for scanning - and I'm not ready to start that discussion as I have my experience but I haven't done enough research about it to suggest others should do what I do.

If your scanner can't scan into the dark areas of the neg, try and get a better scanner. Any drum should be able to and there are many good used ones out there. On the other end of the spectrum, if you don't properly expose for the shadows they will be clear and no amount of PhotoShop curving will get detail where there isn't any.

Better scans come from better negative exposure and development. Period.

That said, you don't have to go crazy and do the whole BTZS thing or something else. We had a thread about this not too long ago and there are many ways of doing the zone system that are quite simple.

1) Measure Zone 3
2) Measure Zone 7
3) Subtract 7 to 3 to get the spread of zones in your image and get your development number.
A range of 4 stops is normal (N) for me, other folks use 5 or 6. In my system, that means 5 is N-1, 6, N-2, etc. It doesn't really matter, what matters is the times you use to expand or compress the range that match to your N, -1, +1, and so on. These you keep on your darkroom wall and continually update until they are spot on. Then you adjust some more because you get so excited about them being so perfect that you agitate more.... etc.

4) Close down 2 stops from your zone 3 reading and expose....

That's it... 4 simple steps.

Expose for the shadows and develop for the highlights - yes, still...

The one other thing is that many labs (not all) should never develop b&w film. B&W is much more sensitive and one should really develop their own, IMO.

Lenny

jcoldslabs
28-Jan-2012, 21:57
Darkroom developing and printing skills are just that, skills, as are scanning skills. I have yet to get scans that match what I was able to do with an enlarger. (It's been a while since I've had my own darkroom, though.) It may be that my scanning talents are lacking, which I believe they are.

If you are only scanning negatives then go with a film/exposure/developer/dilution/time combination that works for your process. I'm not sure one is a substitute for the other.


EDIT: I will say that since I scan my negatives these days (while holding out hope of getting a darkroom again someday) I find myself tweaking my development times in order to make the scans better. This may screw me up down the road if I ever start printing again.

Peter Gomena
28-Jan-2012, 22:09
I taught a friend to scan using his meticulously developed b&w negatives. He used the BZTS system consistently and well, producing negatives that printed beautifully. His negatives scanned beautifully as well, good shadow detail and highlights that rarely touched the right side of the histogram. His scans print easily and well. Good in, good out. Difficult negatives in, fight to make it work all the way through the process.

Peter Gomena