Zone System | Hacker News Reader

Zone System

en.wikipedia.org

23 pointsprismatic12 comments

I feel like Wikipedia kind of glosses over how you might use the Zone System. The idea is that you sample a part of a scene with a spot meter, then use exposure compensation to "place" that part of the scene in a particular zone. I do a lot of B&W film photography, and my go to technique for landscapes is to find the darkest shadow, dial down the compensation to -3 (thus placing the darkest part of the image in Zone II), and then expose the image at that setting.

Digital sensors have different physical properties than film, namely that they clip to pure white rather than clip to pure black. (An overexposed digital picture may have no recoverable detail, while an underexposed film picture may have no recoverable detail. So for digital you want to err on the side of underexposing to capture all the highlight detail, whereas on film you want to err on the side of overexposure to capture shadow detail. Film is somewhat non-linear, too, further favoring overexposure. See also, "reciprocity failure".) So for digital, you aim towards making the brightest object in the scene pure white. You can also skip the zone system and just tune the exposure compensation until the histogram touches the right side. With a spot meter you can practically sample only a few points in the scene; with a digital camera's histogram, you can sample every pixel. Ansel Adams would have enjoyed that.

I remember reading an interview with Adams in a Swedish photo magazine in the late 70s, early 80s. Even then "electronic imaging" was on the horizon, and Adams was looking forward to it.

100% Zones system with spot metering is what you did before the advent of live histograms. Digital flips the bias from overexpose to underexpose and the response is far more linear than film was.

That said its good to have learned these concepts and have them in mind as it makes you a better shooter even in an auto-everything digital photo world.

For example understanding the gray level the camera meter is averaging for and how that impacts the exposure compensation if you are shooting say a bright white snow scene vs a dark blacks & grays street scene.

Phenomenal explanation.

With newer mirrorless cameras, I can live view any overexposed highlights in the viewfinder and adjust from there.

With film, I'll shoot a second shot with an extra stop overexposed. Sometimes I'll even remember to compensate for the bellows draw.

ETTR, Expose To The Right is probably the best way how to get the best image quality possible.

> An overexposed digital picture may have no recoverable detail, while an underexposed film picture may have no recoverable detail.

There's a further nuance here... that depends on whether it's negative film or reversal (slide) film. Overexposed negs are better than underexposed, as you say, but the opposite is true for slides. People who shot "chrome" films would often underexpose by, say, half a step, while the opposite was true for those who shot negs.

True. I totally forgot that slide film existed since they stopped making Velvia. (I use Ektar for color.)

Velvia 100 is gone, but Velvia 50 is still available (though the large sizes aren't imported to the US). Then there's Fuji Provia, my favorite of Fuji's reversal films. In fact I just ordered 10 rolls of Provia in 120 film.

> I do a lot of B&W film photography, and my go to technique for landscapes is to find the darkest shadow, dial down the compensation to -3 (thus placing the darkest part of the image in Zone II), and then expose the image at that setting.

There are some subtleties: Bruce Barnbaum argues you should expose shadows (where you want to keep details) to Zone IV:

* https://www.youtube.com/watch?v=rlnt5yFArWo

Then you take the negative and print it down to Zone III: you end up with more texture / separations.

On the highlight recover for digital: you mean if it is fully clipped to white (max value in each color) over an entire region? Otherwise you can highlight recovery through adjacent pixels in whatever colors are not completely blown out, or through other adjustments from the raw values. Or did you mean something different?

e.g. https://www.darktable.org/2016/10/raw-overexposed/

I still use Zone system when taking portraits with film cameras. Meter the subject's face, then expose at Zone VI (for Asian folks with lighter skin tone).

Works great.

For those interested, I would recommend Ansel Adam’s books “the camera” ,”the negative” and “the print”.

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