A Zone System Question

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Carl Hall

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So I’m trying to wrap my head around the zone system, and I've read a lot about it this afternoon (don’t tell my boss!). I’ve got a photo idea planned for this weekend and I want to get the exposure spot on (poty!), just need to make sure I’m on the right track...

Say I rock up to a scene where the difference in exposure between the shadows and highlights (or more correctly, the shadows and highlights where I want to retain detail) is only two stops. I meter the shadow with a spot meter (er, my iphone app...) which gives me an exposure of 1/30 at f/11. The meter has put this as middle grey, or zone 5, and I want to get it down to zone 3, so I knock it down 2 stops to 1/125 sec at f/11. I then meter the highlights which come out at 1/8 at f/11 (two stops higher than the shadows), but as I’ve bumped the shadows down to zone 3, these highlights are now at zone 5. Am I right in saying I shoot the scene at 1/125 f/11 for the shadows and then do an N+2 development to push the highlights back up to zone 7?

Am I on the right sort of track here or am I way off? Been working this round in my little brain all afternoon and I think I’ve fried it :confused:

Cheers :)
 
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1. If the shadow requires an exposure of 1/30 at f/11 to put it on Zone V and you knock that back to zone III by exposing at 1/125 at f/11 then

2. if your highlight is only two stops brighter, you've got a pretty flat scene - abnormally low contrast.

3. If you meter the highlights at 1/125 at f/11, then that gives you the highlights on Zone V and you want them two stops further up the scale.

4. Hence you increase development to increase the contrast by two stops.

Put that way, yes you are on the right track.
 
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You better make sure you spot meter is calibrated if you want the exposure measurements to be reliable.
 
StephenM said:
1. If the shadow requires an exposure of 1/30 at f/11 to put it on Zone V and you knock that back to zone III by exposing at 1/125 at f/11 then
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Aha, how did I get those numbers wrong?! I said I fried my brain thinking about it all too much :)

StephenM said:
2. if your highlight is only two stops brighter, you've got a pretty flat scene - abnormally low contrast.

3. If you meter the highlights at 1/125 at f/11, then that gives you the highlights on Zone V and you want them two stops further up the scale.

4. Hence you increase development to increase the contrast by two stops.

Put that way, yes you are on the right track.
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Brilliant, sounds like I've just about got the very basics of it. Enough of it that I can go out and try it out at least. Cheers Steve :)

One last question, is the zone system as relevant for negatives which are only going to be scanned? My usual method for shooting film is to meter for the shadows as middle grey and then let the highlights fall wherever they may, then bring everything back down in either the scanning step or the editing step afterwards. When I used digital I would push the scene as far to the right as possible without clipping highlights and then bring it back down in post processing to limit noise. I guess I've brought this method across to film with me too, except that I don't have to worry nearly as much about the highlights.

I think I might do two frames of each shot for a few weeks, one using the zone system and the other shooting for the shadows and developing normally, adjusting at the scanning stage. Then I can compare the two and see what difference it makes
 
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I thought that you got the numbers right and I was agreeing...

I don't personally think that the Zone system matters as much if you're scanning rather than printing in a darkroom. The problem with conventional printing is fitting the negative contrast range to the much, much more limited range of the printing paper. This is the big limiting factor. In my experience, if you maintain shadow detail you can get the highlights back with no problem in scanning; I have a photograph of a church interior where the stained glass and the dark pews both have full detail and all I worried about at the time of exposure was the pews. I'm afraid that all I'm concerned about these days is making sure I have enough shadow detail as I've never run into problems (with my subjects) with the highlight end of the scale.

In theory, if you take the two shot approach, I'd expect that you might find more highlight grain in the non zone system one (since more exposure = more grain) but equally I'd expect you to have to look hard to find it.
 
Another quick question (thought I'd post here rather than create a whole new thread)

I took a photo at the weekend which needs an N+2 development. I've read that each stop is 20% extra dev time. How is this calculated for multiple stops? i.e Fomapan 100 in Rodinal is 9 minutes, or 540 seconds. Do I calculate this as 540 x 1.2 x 1.2 to get 777 seconds (12 mins 57) or do I do 540 x 1.4 to get 756 seconds (12 minutes 34?) Not sure if the 21 seconds difference would matter that much over nearly 13 minutes but it's something I've been wondering for ages!
 
Carl Hall said:
I took a photo at the weekend which needs an N+2 development. I've read that each stop is 20% extra dev time. How is this calculated for multiple stops? i.e Fomapan 100 in Rodinal is 9 minutes, or 540 seconds. Do I calculate this as 540 x 1.2 x 1.2 to get 777 seconds (12 mins 57) or do I do 540 x 1.4 to get 756 seconds (12 minutes 34?) Not sure if the 21 seconds difference would matter that much over nearly 13 minutes but it's something I've been wondering for ages!
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My cat's breath smells of cat food ... :confused:

I've no idea. I'd probably stand develop it for an hour and recover the contrast in LR. Because I'm lazy.
 
At that time 21 seconds isn't going to make any demonstrable difference but if you've shot this on the view camera its easy enough to test. Do one sheet at x1.2x1.2 and another at x1.4 and see if you can see the difference in scanning.
 
That sounds like a plan I think Steve, I've already taken the photo so I think I'll just go in the middle with 12:45 with this shot, but I might take a few more photos over the weekend and do a bit of testing.

Think I might also try doing a test between a shot exposed and developed using the zone system, and another where I just shoot for the shadows and pull the highlights back in Lightroom. I'm sure that test has been done a million times by a thousand different people but it will be interesting to see for myself.
 
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