Mythbuster "You have to expose for the shadows and develop for the highlights"

fhovie said:

I read that "Moonrise over Hernandez" was an exposure based on pure guesswork and that Ansel struggled to get a good print.

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More like ... biased guesswork. Folklore has Adams mulling over the brightness of the moon, and its color temperature - but he simply did not have enough time for fussiness. Is my memory "off" (happens), or did he in fact make two exposures of Hernandez; the first a total failure, and the second, the one that we now know.

That was, by no means, a "straight" print - and Adams never ceased trying to improve the image. Many years after its original publication, he would retrieve the negative and try something else...

Adams gives his full account in his "examples" book, but as I recall the story, he made one exposure based on his quick calulations, flipped the holder to make a second exposure just as the light failed on the foregound. Maybe there is a second neg, but it probably is a dud.

Ed Sukach said:

More like ... biased guesswork. Folklore has Adams mulling over the brightness of the moon, and its color temperature - but he simply did not have enough time for fussiness. Is my memory "off" (happens), or did he in fact make two exposures of Hernandez; the first a total failure, and the second, the one that we now know.

That was, by no means, a "straight" print - and Adams never ceased trying to improve the image. Many years after its original publication, he would retrieve the negative and try something else...

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Hi Ed,

Adams talks about this in one of the DVD's where he stated that he made one exposure and was in the process of preparing to make the second and the light went away off the crosses in the cemetery, so no second negative. Here's his description in The Negative, abbreviated by me from the text:

Calculates the exposure Using the "Exposure Formula" he had tucked away in the back of his brain somewhere, pg. 66 in the book for those interested:

-he recalls that the moon was 250 c/sq ft
-placed that luminance on ZVII
-calculates that 60 c/sq ft would fall on ZV
-uses a film of speed 64, calculates that the exposure would be 1/60 at f/8
-allows for a filter factor of 3x (#15), which adjusts the basic exp to 1/20 at f/8, or about 1 sec at f/32, which is the exposure given
-he indicated water bath development of the negative to support the low foreground are of the image
-ultimately he intensified the foreground area of the negative using Kodak IN-5 intensifier.

Chuck

Just making reference to divided developers...

JBrunner said:

I'm a little baffled by this epic contribution.

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....being able to handle high SBR's without lots of brain damage. Ho hum.

David H. Bebbington said:

... why not take this as a basis, forget the [non-]scientific experiments and go out and take some pictures? Or take a break from the heady thrills of amateur densitometry by doing something really exciting, like collecting toothpicks?

Regards,

David

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David,

You made me laugh so hard, beer shot out of my nose... and that was a damn waste of good beer.

CPorter said:

Adams talks about this in one of the DVD's...

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Yes, I know. I think St. Ansel was ... sort of "expanding" on the process, rather than recounting actual second-by-second history. That would have been something like, "I SAW IT!! I slammed on the brakes and grabbed the triopd..."

A lot of this was performed as a sort of conditioned reflex, rather than meticulous calculation. We all do that - that is the real reason for learning.

Expose for shadows...

All light meters which measure reflected light are calibrated to 18% gray. If your scene allows the use of a gray card then you can meter off of the card and let the lighter and darker tones fall where they should. If a gray card can't be used then there is incident metering. It is true that with very flat light or very contrasty light you can adjust exposure and development to compensate. This was known long before the Zone System. I am skeptical of claims that film is rated up or down from box speed because I don't know what tone the photographer was metering from. In some cases a change from box speed is necessary. Film developed in undiluted Microdol-X/Perceptol will lose some speed and film developed in phenidone type developers will pick up some speed.

When I use a Canon F-1 I am careful to meter off of a mid tone. If I use a camera with average or center weighted metering I use a different technique. In most situations the gray card is a good reference. This is true whether or not you are using the Zone System.

Ed Sukach said:

Yes, I know. I think St. Ansel was ... sort of "expanding" on the process, rather than recounting actual second-by-second history. That would have been something like, "I SAW IT!! I slammed on the brakes and grabbed the triopd..."

A lot of this was performed as a sort of conditioned reflex, rather than meticulous calculation. We all do that - that is the real reason for learning.

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Yeah, I suppose it could've been that way, IDK. I wasn't there so I can't say what I think he was actually doing---that's how he says he arrived at the exposure and I have no reason to question it. It's one of those things that I take at face value, regardless of who it comes from.

Last night - I was on my way back to LA from Vegas and the sun was setting - behind some clouds - over an abandoned mining building. This is like buck fever - Looks like a great shot! - How fast can I get my Tachihara assembled and a lens and exposure figured and all done. I did brilliantly! After the camera was back in the car I realized that I had grabbed the IR film pack and not the FP4 film pack. Now it is really a Chinese fire drill! I set it up as quick as I could - Shot one sheet with an added stop for the light that was failing and then doubled the exposure again just in case. There is of course the possibility for a serdiptious masterpiece but I will always hedge my bet on a little more light. We will see this weekend. I had never equated capturing a decisive moment with deer hunting before - but not all exposures or great images have the luxury of unending contemplation. Sometimes you just got to shoot the thing and get as much light from the shadows as you can get. I had an SBR of 13. Will likely need to under develop if I want to get detail in the clouds around the sun.

Just to restate things a little differently.

Bill used a method similar to ISO & ANSI & ASA, where the minimum exposure to get a usable negative is determined. This method, by definition leaves no underexposure latitude and all the exposure latitude is for overexposure.

Sam's technique was that of rating slide film. By definition his method has no overexposure latitude. All his latitude is in underexposure.

If you 'split the difference' between the two methods you can target you exposure for the middle of the curve, and therefore get 3 stops of latitude for both overexposure and underexposure. Happy Shooting!

Hi ic-racer,
Thanks, an enjoyable thread. Good explanations of those mysterious “ reduce your EI from 100 to 80 and reduce your development by xyz % “ that turn up in various books. Now I know why these work; at least to a degree, a degree of “works” I mean. Not having a working densitometer I live by notes and adjustment, not maybe the best way but I do keep out of mischief and my prints continue to improve.
Best Regards
Rob

ic-racer said:

Just to restate things a little differently.

Bill used a method similar to ISO & ANSI & ASA, where the minimum exposure to get a usable negative is determined. This method, by definition leaves no underexposure latitude and all the exposure latitude is for overexposure.

Sam's technique was that of rating slide film. By definition his method has no overexposure latitude. All his latitude is in underexposure.

If you 'split the difference' between the two methods you can target you exposure for the middle of the curve, and therefore get 3 stops of latitude for both overexposure and underexposure. Happy Shooting!

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Dear ic-racer, I freely admit that I tried (3 times) and failed to understand your original posting ( I speak as a qualified professional photographer and former technical writer for Ilford Limited). However, I must say that the above statements are total nonsense.

If you determine exposure on the basis of a shadows reading, then (assuming your reading is accurate) you will obtain correct [minimum] shadow exposure. That is all - there is no direct relation between this exposure and the amount of latitude you can exploit, since this depends on the subject brightness range and the contrast to which you develop the film. If the SBR is "normal" (128:1) and the development is "normal" (G bar 0.55) you will record all tones in a printable form but exposure latitude will strictly speaking be zero (it may be one or two stops, even three, if you are willing to tolerate highlight degradation). If you increase shadow exposure, there will be even less "latitude". The only way to increase exposure latitude is to downrate the film's EI and develop to a lower contrast.

In the reverse case, basing exposure on a highlight reading will if done correctly ensure correct highlight exposure (maximum possible while retaining detail). Again, with a normal tone scale, there is virtually no latitude except at the expense of shadow degradation. In the case of a transparency shot for projection, latitude is virtually non-existent, there is essentially only one optimum exposure plus a short range of sub-optimum degraded but perhaps acceptable (under-)exposures. Decreasing the exposure can hardly be considered to be exploiting latitude - there are numerous exposures which will record highlight detail, but shadow detail will be hopelessly dark. There is no meaningful sense in which you can draw on 3 stops exposure latitude in both the under- and overexposure directions!

ic-racer said:

Just to restate things a little differently.

Bill used a method similar to ISO & ANSI & ASA, where the minimum exposure to get a usable negative is determined. This method, by definition leaves no underexposure latitude and all the exposure latitude is for overexposure.

Sam's technique was that of rating slide film. By definition his method has no overexposure latitude. All his latitude is in underexposure.

If you 'split the difference' between the two methods you can target you exposure for the middle of the curve, and therefore get 3 stops of latitude for both overexposure and underexposure. Happy Shooting!

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What exactly is it you are trying to convey to potentially 25,000 other members?

I would pass this on to folks who are new to film. I lack the skills to put it any other way but, IGNORE IT!! You will experience no gains in your understanding of exposure and development if you don't----only headaches.

The phrase "expose for the shadows and develop for the highlights" is an old, but very true, principle in photography. There's different ways to apply that principle i.e., ZS or BTZS, or simply overexpose and underdevelop, with the latter practice being a much less refined application of the principle than ZS or BTZS. So, get the most out of your film of choice and expose for the shadows and develop for the highlights. It works quite well.

CPorter said:

..... film of choice and expose for the shadows and develop for the highlights. It works quite well.

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referring to "negative" film, of course.

CPorter said:

..... film of choice and expose for the shadows and develop for the highlights. It works quite well.

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Hi

strangely, when I've tried altering development by extending development for extending the contrast I didn't get much change, getting only minor extension in the dark areas.
{double time development}
I've found on my 'densitometery' that I have a useful range of exposure which is limited by the base fog (if that's the right term here) in the shadows {meaning I can no longer tell the difference between image and murk}. I'm limited in the density where I can no longer tell the difference between fully over exposed film and highlight detail. Something like this range.

(give or take at the boundaries)

As shown above my density barely shifted with double time N+ development. Perhaps my mistake was to have exposed a scene with too much contrast for this experiment? Perhaps I'll repeat this again if anyone thinks this might be my root cause.