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"Expose for the shadows"


WarriorJazz

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I was just reading my M6 manual about exposure metering and came across the golden rules. The rule for B&W film is:

 

"Expose B&W film for the shadows, and develop for highlighs."

I'm not shore I understand this rule. How will this work in real life?

I read the rest of the chapter on metering and learned about all the different situations and how to expose them but not all of these use the rule that you should expose for the shadow...

 

And what do they mean by ...develop for highlights? How do you do this?

 

Maybe I'm seeing this all wrong or making this more complex than it should be, but can somebody tell me how I should apply this rule and how to use the exposure meter at it's best.

 

Regards,

 

Eelco

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It literally means: over expose (longer exposure, more light on the film) and under develop.

 

It would be the digital equivalent of exposing the histogram to the right, just before highlights clip and pulling the exposure back down in post processing for maximum shadow detail and no blown highlights.

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I would not worry too much about this if I had just bought an M6. Use the meter and follow the simple rule in the handbook, which I have not at hand, but which I think says more or less: large very bright (dark) sections in the area measured by the light meter will lead to under- (over-) exposure and you should take this into account by adjusting exposure by one or two stops.

 

The rule you mentioned is based on the fact that film emulsion sensitivity is more or less determined by the film you use. That means that if you want your negative to register details in the darkest parts of your picture you need to give it enough exposure (light). No matter how long you develop, there will not be any more detail shown once you have reached a certain level. Thus expose for the shadows.

 

With the highlights (the bright areas in the picture and thus the dark areas of the negative) it is different. The longer you develop, the darker these areas get on the negative. You do not want them to get too dark because then there will be no details on the print when you enlarge (unless you use a lot of tricks when printing and there are limits to how effective these tricks are). Thus develop for the highlights.

 

Other persons may explain this differently, and they will probably be correct. ;-))

 

If you do your own developing, and want real good negatives, the basis for beautiful prints, then there is no way around establishing your personal optimum film speed setting and the optimum development time. Volumes have been written on how to do this.... But it is not difficult.

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"Expose for the shadows" is good advice for just about all B&W negative films in most ordinary photographic circumstances. The idea is to give enough exposure to be sure to get detail in all the shadow areas where you want it.

 

Most of the time you can leave it at that: expose for the shadows and develop normally. This is because the range of most B&W films is as wide or wider than the range between the important shadows and important highlights in most scenes.

 

If you have a very long-range scene (e.g. you're trying to get a picture of something in deep shadow with a sunlit beach background), exposing for the shadows will mean that the highlight areas of the image get so much light on the film that the negative will be pretty much solid black - i.e. you lose detail in the background). Cutting the exposure so the background is aceptable means that you lose shadow detail.

 

One way to reduce this problem is to expose for the shadows and then reduce the development time so there is still some detail in the shadows but the dark highlight areas on the negative aren't blocked out. In other words you're producing a less contrasty negative.

 

An alternative is to cast more light into the shadow areas (reflectors, flash...) .

 

Conversely if you have a very short-range subject (no real shadows and no real highlights), exposing for the "shadows" will give you one or two stops less exposure than an averaging or incident light meter would say. If you then develop for longer than normal the result will be a negative with more contrast between the lightest and darkest areas, from which it will be easier to make a good print.

 

Both these techniques are less important if you're scanning and Photoshopping your negatives than if you're making prints the old way. But some users routinely overexpose and underdevelop all the B&W film that they intend to scan. This is because many scanners can't cope with the full contrast range that some films can deliver.

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You either need to start reading about the 'Zone System' or take some instruction in B&W film exposure, developing and print making.

The 'Zone System' ranges from Ansel Adams teachings to a simplified 5 Zone approach.

Ideally one would expose each emulsion and develop for a single photographic situation.

With large film format, this is easier to do but with 35mm, if taking many different scenes on one roll of film, not easy to do if at all, so photographers that wanted upmost quality used to shoot a roll of film for each situation and develop and print for that situation if possible. Not hard if you are a professional but difficult if any amateur that sometimes may go long periods between exposing frames on the same roll of film.

Anyway its worth learning about.-Dick

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Shadows complete development early in the processing, while highlights continue to develop, thereby making the range difficult to print - blown highlights or no-detail shadows. Expose for important shadow by under-rating the film a stop and under-develop by about 15 to 20%.

 

Or use B&W film that's developed in the commercial one-hour color machines.

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Thanks all for your explanations!

I've looked into the Zone System a while back and it confused me. It all seemed a bit complex.

I develop my own negs and use them for scanning. I'll make prints in de future but I I currently have no room in my house for this ;-)

 

Shadows complete development early in the processing, while highlights continue to develop, thereby making the range difficult to print - blown highlights or no-detail shadows. Expose for important shadow by under-rating the film a stop and under-develop by about 15 to 20%

 

So If I get this correctly you expose your tri-x 400 @ 320 and use 15 to 20% less development time?

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Tri-X @ 320 developed for 10% shorter time than "recommended"

 

There's a Tri-X album of mine here where you can judge for yourself whether that's suitable for your needs.

 

Thanks for the examples! They look great! Truly love this shot:

http://www.l-camera-forum.com/leica-forum/members/21194-albums17-picture2827.html

 

I'll shoot my next role @ 320.

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The late photographer Fred Picker did not follow this practice. He tested for true film speed to understand the proper exposure to get Zone I. Using that ASA (ISO), he tested to determine the proper development time that would yield a Zone VIII print value when the negative was given the minimum enlarger exposure to print black through clear film.

 

Once knowing these lower (Zone 1) and upper (Zone VIII) print limits, he would find and meter the brightest thing in the scene (not specular highlights), expose it for Zone VIII, and accept what there was in the shadows. That way he used the broadest exposure range without blowing the important highlights.

 

Fred was a curmudgeon, with many detractors, but he was a very good teacher. I shot b/w film for a couple of decades using many of his methods. Worked like a charm (as would any system that is disciplined, consistent and follows principles of film latitude and exposure).

 

Jeff

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Hi

 

The rule in title means you need to understand and use Ansell and Westons zone system, in a way adopted to your camera, light metering and film.

 

Hard work if you dont use the camera regular and are not of a mathematical bent.

 

I carry a Westom meter which allows you to meter of a shodow, that you want in zone I or II and set the esposure without doing sums in head. You do need to know the film and developing technique.

 

This is the reason why some people say stick with the same film, the more exact rule is shoot a test roll to find out where zone I and II are. You should also test to find out where the film runs out of highlight range unless you like burnt highlights.

 

The reflective mater average is ok 99% of time i.e. kodak did experiments, 99% was answer, the Leica manual tell you where the delinquent 1% occurs and what to do... if you read and understand it.

 

Noel

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It simply means expose just long enough to get printable separation in the dark values.

 

Develop just long enough so the the highlights are not grey but have not become blocked so they still show detail.

 

Exposure controls shadow or dark values. Time in developer controls the density of highlights. Theses rules always work and that is why they are the golden rule. It NEVER changes.

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Fred's approach is simple to understand, it is rigorous, and very easy to use in practice. And it produces the best possible negative available.

 

It is particularly easy with XP2 and 400CN - the ASA test results in 200 ASA being the speed that produces the right Zone I, and development time is the C41 time (i.e. the processing machine time). It yeilds wonderfully rich negatives every time.

 

Long live (the late) Fred Picker.

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Fred's approach is simple to understand, it is rigorous, and very easy to use in practice. And it produces the best possible negative available.

 

It is particularly easy with XP2 and 400CN - the ASA test results in 200 ASA being the speed that produces the right Zone I, and development time is the C41 time (i.e. the processing machine time). It yeilds wonderfully rich negatives every time.

 

Long live (the late) Fred Picker.

 

Do you mean that both of these films should be shot/exposed as though they are 200asa instead of 400asa and then developed as though they are 400asa?

 

Thanks

 

Tony

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So If I get this correctly you expose your tri-x 400 @ 320 and use 15 to 20% less development time?

 

Depends upon which Tri-X I am using. There is not just one version. 35mm I expose at about 200, underdevelop 15%, unless using FG7 and 15% sodium sulfide of which have very little left, so as an alternate I develop using D76 1:3 for contrasty scenes,

 

For 120, a film that has two different ISO ratings, and one intended for tungsten I use stand development

 

For large format, I keep it at recommended ISO and over-develop by 10%. Go figure.

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Do you mean that both of these films should be shot/exposed as though they are 200asa instead of 400asa and then developed as though they are 400asa?

 

Thanks

 

Tony

 

Yes.

 

For development, take them to a shop with a C41 machine. There is a standard development process that works. Let them do it - it is cheap and fast and probably more consistent than you can manage.

 

In fact, you should do a test to determine what ASA your camera/meter/film combination requires (this is the key - you should test). But in my (and many others) experience, those two films are actually best exposed for 200 ASA. For the test (and some quite good explanations see Digital Photography Courses | Ansel Adams Zone System).

Edited by Michael Hiles
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Do you mean that both of these films should be shot/exposed as though they are 200asa instead of 400asa

 

Actually, the language would be longer-exposed at 200 rather than 400. NBD.

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