Question about metering shadows and highlights
Got a rather schoolboy question but it's been something on my mind for a while as I try and improve my metering methods and get better exposure.
Shooting black and white negatives - I (spot) meter for the darkest part of the scene I still want to see detail in, which will sit in zone 3. That's fine. And then I understand I need to get a reading of the highlights so I can use this information when I develop the negative and make any adjustments necessary.
If I meter for the shadows and get a reading of say f/16 at 2 seconds and then to put this into zone 3, this works out to f/16 at 0.5 seconds. I then meter for the highlights and get a reading of f/16 at 1/250 second. To then get the scene brightness range, I have my reading for the shadows and reading for the highlights. However! For the shadows, am I using the reading the meter gave me or the value I'm working with to put the shadows in zone 3?
Ie. am I using the 9 stop difference between the metered readings (f/16 at 2 seconds to f/16 at 1/250) or the calculated 7 stop difference (f/16 at 0.5 seconds to f/16 at 1/250) to get my scene brightness range?
Thanks very much!
Use multigrade paper and forget about the highlight reading. Adjust the contrast during printing, rather than film development.
Thanks for the tip. At the moment, I'm printing with inkjet and I guess I can adjust in Photoshop (if needs be). When room for a darkroom allows, I'll certainly take onboard your advice and try it out!
Aside from that, is there anything else you can suggest to getting a correct exposure or am I good metering for the shadows? Or metering for whatever my main subject is and putting that into the relevant zone?
Dunn and Wakefield, Exposure Manual
Get as Late a version as you can.
Mark Barendt, Ignacio, CO
"We do not see things the way they are. We see things the way we are." Anaïs Nin
In ZS practice, the luminance ratio would be determined between the "placement" of the desired shadow luminance and the "fall" of the desired highlight luminance. Making the shadow "placement" sets the gray scale so to speak, because all other luminances fall on the gray scale relative to your "placement" of the desired shadow area. In your example, the way I see it, you have a luminance ratio of 128:1 between Zone III and Zone X.
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9 stops is pretty long range, we have some people here who "live" in that territory. I hardly ever get meter readings over 4 stops range and I have to pretend there is something darker and lighter so I can admit my picture is Normal.
You use the whole 9 stops in your example.
But maybe you are pointing the highlights at something that isn't important. There are going to be things in your picture that are darker than your darkest meter reading. These are supposed to fall into blackness, like open doors. And the spectral highlights, things that reflect the light like mirrors and chrome, are supposed to go off into pure white.
If you really have 9 stops, then you might use N-2 development in classic Zone System parlance. Or you might do as ic-racer says and ignore it and make up the difference with Multigrade Paper which these days is pretty remarkable.
But I am guessing you might be metering something that is irrelevant. Point at the most significant shadow, point at the most significant highlight. Leave some room for some things to be darker and lighter.
Originally Posted by Bill Burk
That was just an example off the top of my head but actually gave me something to think about with such a wide range and that you're probably correct - there's some parts of a scene that are probably not worth considering. I guess part of me, coming from a digital background, has had never blow the highlights! beaten into me time and time again.
You are quite correct that, with digital and transparencies, the key 'rule of thumb' is to avoid highlight blow-out.
With negative materials the converse is true - you need to expose for adequate shadow detail.
Personally, I meter the shadow area where I wish to retain shadow detail and place this on Zone III. I then develop using a two-bath developer (Barry Thornton's is very good, very simple, has only a few chemicals and is easy to make) which ensures that I retain highlight detail irrespective of subject luminance.
use the metered difference to get the brightness range
Just wandering what N-2 would accomplish.
Originally Posted by Bill Burk
Just summarizing the example here, a reduction in exposure from 2 sec at f/16 to 1/2 sec at f/16 is a two stop reduction-------if 1/2 sec at f/16 is a Zone III shadow placement (as stated in the example), then this makes 2 sec at f/16 the Zone V metered value. The 9 stop range mentioned is from Zone V to Zone XIV. Living there and printing it successfully (I realize "successfully" is a subjective thing here) I guess are two different things. This is a very high shadow placement, that, given the contrast of the light, can push even non-specular high values pretty high up there, so what will N-2 accomplish? Not much that I can tell. Let's assume the specular values are at XIII and above in the example, that still leaves a Zone XII luminance needing N-4 to get to a density that will render respectable texture on the print surface, N-3 to render it with some definite tone below paper white.