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In following some of the threads on this Forum, it appears that there is quite an interest in exposure and contrast control, using the methods first formulated by Ansel Adams. I posed the question recently if there were any special "tricks" for applying the Zone System to digital photography? [I guess I was somewhat dissapointed with the response from the group, BTW, so maybe this is just beating a dead horse.] I did pick up a pretty nice, simple book, "The Practical Zone System" by Chris Johnson. Very nice for implementing exposure and contrast previsualization. But also fairly specific to B&W wet darkroom. Digital is covered a tiny bit, but mostly with the slant, "...it's like an expensive television that crashes." The Zone System deals with being able to previsualize what the final print, (or projection, or CRT image), will look like, while in the field, looking at the original scene. It is basically knowing how to corectly use your available tools to execute your artistic interpretation, the way you want to. I've always separated the classical Zone System into two parts, exposure in the camera ("expose for the shadows"), and contrast control on the darkroom, ("develop for the highlights") The principals of exposure control with digital cameras are very similar to those used with analog cameras, but the tools available are often much more sophisticated. Contrast control for digital development, and how the image will finally look on the particular viewing media, is not similar at all. The neatest tool the digital cameras bring to the Zone System is the ability to actually view the histogram of captured brightness range, in the field, at the instant of the exposure. The LCD examples shown here are from dpreview.com, for various major camera brands; Nikon, Canon, Minolta, Sigma, (Olympus and Sony do not seem to have this feature). Looking at the histogram, one can immediately tell if a lot of pixels are "bunching up" at the low end or the high end. Some of the cameras even allow zooming into a smaller section, and showing the histogram of that section. Sort of like a super light meter! Useful in deciding if significant shadow, or highlight, detail has been lost. To a first guess, exposure will be correct if there is no significant "bunching" at either end. Refining this some, exposure will be useable if areas of significant detail are not rammed up against either end. Here, all important tones will be "captured," and one can always then adjust final relationships in photoshop. But if significant detail is lost, at either end, it will later be impossible to recover. [One could imagine a "smarter" digital camera, that measured this histogram continuously, and used the result to adjust the exposure...] Since I generally plan on doing "levels" adjustment in Photoshop, this centering of the histogram is usually sufficient to bring back useable images. [The perceptive will note that I'm lying here, as I do not actually own a digital camera...] Given the ability to zoom to a particular area, and measure the histogram of that area, would in principal allow the digital photographer to adjust the aperature or shutter speed to "place" that area on any chosen Zone. [Again, I think this is neat stuff, worthy of some mini-tutorials. But that may be only my twisted slant on things... I'd be interested in hearing from you digi-folks; Do you ever use the histogram features of your cameras? What is the best way you've found to capture the correct exposure?]

I am in the process of transfering my knowledge of the traditional zone system into digital techniques.....

In theory it shouldn't be all that much different, but in reality it is VERY different. The basics are all still there and pretty much the same, but getting in a little deeper things start to get tricky...A ccd is more like shooting transparency film, so right off the bat things get flipped around all backwards....expose for the shadows...nope expose for the highlights and develop for the shadows?.....what about color? f/stop increments in digital are different than film....crap there go all the nice even 1 stop,2 stop,1/2 stop adjustments.....Expansion and contraction in development?,,,,,there is no development anymore with digital....so now I am also working on precise Photoshop actions for this purpose....of course it depends on the camera you are using......

Histograms are nice.....still it gets way more involved to recreate that pre-visualised image in your head....

This is gonna take some time......Whew!

I don't agree about the comment to digital cameras... I didn't read all, I'm tired, but that comment I cannot understand well :(

f/stop increments in digital are different than film Really? Not sure I understand this myself. Ya, seems like the CCD runs up against exposure limits at both the high end and at the low end. The dark end is limited by noise, and the high end by blooming. And somewhere in here comes the limitations of the 12 bit (or so) A/D converter. If (?) cameras allow manually setting the white points and black points, it should roughly be equivalent to changing the development time... Once the bits get into photoshop one can adjust Brightness and/or Contrast. I suspect this is roughly equivalent to changing exposure in the enlarger, and using different contrast grades of paper? Maybe together we can figure this all out so it makes sense.

Am I wrong in stating that the "zone system" is a matter of previsualizing an exposure prior to taking it, taking into consideration the detail recording range of the particular film being used (in B&W's case roughly a ten stop range between blocked up black and washed out white) - then, based on this knowledge, placing the subject into whatever "zone" you want to expose it for, keeping in mind that the highlight and shadow zones will also be shifted (Or, in Ansel's case, placing the shadows in zone 1 to 2 as to not block them up, the developing for detail in the highlights - which works fine for NEGATIVE sheet film, but impossible for roll film....which may be why the Zone system has become this "mysterious monster" - exposing for the shadows and developing for the highlights works for negs because density is built up in highlights before it's built up in shadows - but the opposite is true with transparency film...the rule there is to expose for the highlights and let the shadows fall where they may (or adjust the lighting for the shadows) - the reason being that washed out highlights with transparencies will be forever that - washed out - there's no density there to correct. The zone system is based on the knowledge of the recording and print media's tonal range and contrast range, placing the exposed image within that range to achieve the desired result. this will differ depending on the materials used. the classic "10 stop zone system" is completely useless with transparency film (as the contrast range is reduced to about seven stops), as well as the axiom of "expose for the shadows, etc." is now completely reversed. Not being familiar with the digital format, I have to wonder what the contrast range of the medium is and whether it acts more like transparency film or negative film...? Whichever the case, it's a matter of determining the contrast range of the medium and dividing that into "zones", allowing a previsualization of the final image and the exposure placement of the elements of the composition. Photoshop has entered the venue as a confusing element, making it that much more difficult to determine what is actually "correct" - being that it has the ability to "correct" images to a previously unimaginable degree - but there's not substitute for a perfect exposure.

I'm going to be honest and say that I never use my histogram when using my digital camera, I simply use my 'eye'....btw I couldn't figure out how to get that cute little screen shot of the in-camera histogram. I've always been of the opinion that the Zone System is the Zone System no matter what kind of camera (traditional/digi) you may be using. What film is another story though as Wolfsnap states... However as I said above I've never tried to put the ZS into use while using my Dimage7. I can see the shadows lighten/darken with the turn of the wheel....same for the highlights. I guess I'm just not a techy person...it's all visual for me. This shot here is the actual from camera unprocessed image, and the screen shot of the histogram from the image using the camera's software....this histogram matches the one in camera. Of course this was done by eye....with thought to the histogram, uhh, just a few moments ago. Of course it still needs to be adjusted, but not much.... Very interesting stuff Misha.....

I think Wolfie explained the concept very well! The concepts do not change. Thank you, Michelle, for the beautifully exposed teddie. It looks (on my monitor) that Zone III is precisely on the nose, (I couldn't resist!). Some of the highlights in the fur, and the edge rim of the eye, are around VIII or IX. Exactly as they should be. The histograms are also about what I would expect for a perfectly exposed photo. No big spikes down around 0, or up around 255. The BIG Question: How easy is it to use the little LCD finder to determine if you've really captured the shadow and highlight detail you want? I'm not really suggesting that folks ALWAYS use the histograms in the field. That would be sort of a pain in the butt. In tricky lighting situations, however, it seems like the histogram is a nifty tool. If you see that pixel values were bunching up at either end, you could adjust the exposure some to play "safer." In the teddy picture, there seems to be quite a lot of room at the high end, and the shadows are just slightly starting to bunch up. A "safer" strategy would maybe be to increase exposure here by 1/2 to 1 stops, (until you start getting a big spike at 255). This would give some insurance that you've captured enough detail in the shadows. BUT! Even though safer, it would be the WRONG exposure. Increasing by one stop would place everything one Zone higher. Doing a straight print of this then would look far different from your previsualization. So, what you'd like to do is make a note in the field that you compensated by one stop, and then later in Photoshop darken to return to your previsualization. This seems entirely consistant with Wolfie's statement, "The zone system is based on the knowledge of the recording and print media's tonal range and contrast range, placing the exposed image within that range to achieve the desired result." What is nifty about the digital cameras is that you can determine exactly, at the time of exposure, if every significant image element is within the recording media's tonal range. If it is not, you can compensate the exposure, and then later in Photoshop exactly remove the compensation. The statement, "Washed out highlights with transparencies will be forever that - washed out - there's no density there to correct." Would translate into digital media as, "Values falling at 0, or at 255, are forever lost, there is no density there to correct." A nifty digital camera feature would be an "out of range" LCD display. Everything around level 0 shown as bright purple, and everything around 255 as bright yellow. And then a "thumbwheel" to compensate the exposure. Then, I'd like the thumbwheel setting to be recorded with frame information.

Well I know this camera has EV compensation +/- in 1/3 stop increments, but since I never use the camera in auto mode, I've never bothered with this function. The LCD screen can be a real beyotch to deal with on many cameras and your idea is a interesting one.... I've discovered with lots of use that for this particular camera, I usually need to shoot 1/3 to 1/2 stops more to get it right. If it looks ok...I've usually lost detail in the shadows, so I just bracket. Over-exposure is easy to see, but the shadows are tough.....

Not too long ago I read of a technique where you take your bracketed exposures and layer them in photoshop. Then you play with the layering to get some detail in the dark and light areas. Of course the pictures would have to be from a tripod in order to line them up. Never tried it myself. Apparently it comes from some advanced darkroom technique.

Yes, TT! That's one of the places I'd like this mini-tutorial to go. Everything is relatively easy when the scene starts out as low contrast, and you just have to fit it into the capability of the media. When BOTH the low end and the high end are clipped, things get more difficult. With traditional B&W wet darkroom, you could expose for the shadows, and then change the development time to pick up a few more highlights. With digital cameras, there may be some things you can do with setting the black points and white points. I need to investigate this. At the extreme, your suggestion of combining multiple exposures is something which is practical to do. If you find some good links about this, please post them. [I just read an article today, BTW, where Fuji is coming out with a high sensitivity CCD array sandwitched with a low sensitivity array. It should do exactly this! In a few more years folks may wonder why photographers spent so much time on something foolproof like exposure!]

Misha you're such a techno babe! It makes my mind spin! :~)

Oh Hell, I've got to save this page and print it out I think...thanks for all this interesting info Misha (& everyone else who has contributed)...I just have to read it a few times to get my head around it. :-)>