Development time - compensating exposures with 120 film

Just brushing up on my zone system theory before going out tomorrow - it's been a while! I haven't shot black and white for some time and I decided to study the zone system seriously before shooting it again. My question is this:

Assuming my first frame requires N-2 development and the second frame is very low contrast - let's say a two stop brightness range (S-ZIV, H-ZVI) - will the N-2 development effect the highlights in this frame just as much? Would the ZVI highlights be contracted to the same tonality as the shadows (ZIV) resulting in a completely flat, unprintable negative?

With a three stop brightness range, I can compensate with the exposure by placing the shadows a zone higher, then increasing contrast at the printing stage, but with a scene of two stops, I'm not sure if the N-2 development would make the negative unworkable in terms of contrast adjustments.

batwister said:

Just brushing up on my zone system theory before going out tomorrow - it's been a while! I haven't shot black and white for some time and I decided to study the zone system seriously before shooting it again. My question is this:

Assuming my first frame requires N-2 development and the second frame is very low contrast - let's say a two stop brightness range (S-ZIV, H-ZVI) - will the N-2 development effect the highlights in this frame just as much? Would the ZVI highlights be contracted to the same tonality as the shadows (ZIV) resulting in a completely flat, unprintable negative?

With a three stop brightness range, I can compensate with the exposure by placing the shadows a zone higher, then increasing contrast at the printing stage, but with a scene of two stops, I'm not sure if the N-2 development would make the negative unworkable in terms of contrast adjustments.

Click to expand...

Since the N-2 development will reduce the contrast as you desire for the first frame, it will be problematic for other frames on the roll that don't require such a reduction in contrast. IMO,this amounts to a somewhat inefficient use of the film. What medium format camera are you using? If you have the ability to use interchageable backs, it simplifies things greatly to dedicate the backs to N, N+1, and N-1 development, etc.... If you don't have this capability, then, IMO, you should plan the development of the roll that will suit the most desired frame(s) that it contains. The bottom line is, there will be frames that do not receive the desired development with roll film when it is subjected to varying SBR's, gauranteed.

The Zone System and roll film don't often get along well due to the very problem you have exemplified.

If I were you and were trying to get lots of different contrast subjects on one roll to work well, I would standardize on about N-1 development for the whole roll and then use paper grades to deal with differences in contrast. Do make sure you give adequate exposure, especially in contrasty situations, to ensure good shadow detail.

VC papers work better for expanding contrast than contracting them, that's why the N-1 (i.e., "Normal" negative tailored to print well on grade 3 paper). That should give you enough leeway for all but the most extreme situations.

Metering is important in the Zone System. If you use an average meter, I recommend giving contrasty scenes one extra stop of exposure. This seems counter-intuitive at first, but ensures you hold shadows when the meter wants to underexpose them. If you spotmeter, just place the shadows as usual.

I've expounded an entire system for the Zone System and roll film somewhere, either here or at the LF Q&A. If your interested, you can search my posts here and there and find it.

Best,

Doremus Scudder
www.DoremusScudder.com

Old b&w darkroom data guides give a better explanation of time adjustments, in terms of lens coating, flare, subject contrast range. They work only if most of the same light lit all of the frames on the whole roll.

For roll film, I take a reading of the area I want to place in zone V or VI, and expose. I don't concern myself with too much else for sake of losing the shot. Multi-contrast paper, split grade printing, or dodge and burn(or a combination)are wonderful meathods of controlling anything else.

Doremus Scudder said:

If I were you and were trying to get lots of different contrast subjects on one roll to work well, I would standardize on about N-1 development for the whole roll and then use paper grades to deal with differences in contrast. Do make sure you give adequate exposure, especially in contrasty situations, to ensure good shadow detail.

Click to expand...

Yeah, I've read this suggested before and it makes sense with my current one back situation. Multiple backs does seem the only logical solution to the zone system with roll film problem.