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Author Topic: Zone System for Digital Photography  (Read 4687 times)

Jonathan Wienke

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Zone System for Digital Photography
« on: August 19, 2005, 01:45:29 pm »

The Zone system as originally conceived is not exactly applicable to digital imaging. Exposure with digital should be done as described in http://www.visual-vacations.com/Photogr....ies.htm to achieve the lowest noise and greatest dynamic range.
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Graeme Nattress

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Zone System for Digital Photography
« Reply #1 on: August 27, 2005, 01:19:35 pm »

I must admit, coming from an image processing / video background, that I cannot make any description of the zone system make sense in my head, and it makes even less sense with digital photography. I truely believe that when you take a digital photograph, you should be aiming to capture as much (high quality) information as possible to allow you to manipulate the image to achieve your artistic goal for the picture. By aiming to expose your image so that no highlights are clipped, but are as bright as possible achieves this goal. The histogram on the camera is your primary tool for achieving this.

I wish that cameras had an iterative exposure mode that took image after image, analysing the histogram and applying micro changes to either apperture or shutter speed to maximise the dyanamic range. I mean, we do this by hand by looking at the histogram after we take a shot, but it's a mechanical process that the computer in the camera should be able to do with ease.

Graeme
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Jonathan Wienke

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Zone System for Digital Photography
« Reply #2 on: August 28, 2005, 11:49:33 pm »

The biggest reason the Zon System is obsolete IMO is that you can darken tones with digital and not lose any image quality, but not lighten. With film & darkroom processing, one loses quality by moving tones too far either way in post. With digital, quality is only lost when moving tones up the luminanace scale (unless you've blown the highlights), so it makes sense to expose digital differently than one did with film & chemical prints.
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dbell

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Zone System for Digital Photography
« Reply #3 on: August 29, 2005, 03:46:35 pm »

I always felt that the point of the zone system was to help photographers understand the relationships between luminance values in their images and how to manipulate them. When you decide how much exposure you want to give to a particular area (what zone you're going to put it on) the system lets you visualize what the other values will look like and know what will fall outside the range of your film. It's basically a tool for understanding and predicting the consequences of your exposure decisions. I'd say that this part of it still applies to digital capture. Sure, the histogram lets you know right away about how good your guesses are, but I don't see anything wrong with being able to do the mental exercise, especially if you still shoot any film.

The zone system is predicated on the use of B&W negative films. On those films, low-density values must be controlled by exposure. When you develop, you can then give more or less development to control values in the high-density areas (low values are significantly less affected by development time on thick-emulsion B&W films).
Digital sensors don't respond to exposure the same way B&W films do, but they do behave a lot like transparency films. Ansel's advice in "The Negative" about how to apply the zone system to slide films is still useful stuff. IMO, so is the general emphasis on understanding the relationships between the luminosities of various areas of an image.
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Dave Ward

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Zone System for Digital Photography
« Reply #4 on: August 19, 2005, 11:47:38 am »

Does anyone have any experience on using the Zone System (or part of it) with digital photography. I use a Canon 1Ds and although it's metering system seems pretty good, I like the idea of bringing some of the traditional methods into digital work. I heard that digital should be treated more like transparency film with its shorter 'latitude' and easy of exposing incorrectly, so a modified ZS may be beneficial?
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Wills

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Zone System for Digital Photography
« Reply #5 on: August 27, 2005, 11:57:01 am »

This is a good article on the Digital Zone System http://www.erickahler.com/articles/zonesystem.html
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AJSJones

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Zone System for Digital Photography
« Reply #6 on: August 27, 2005, 06:48:55 pm »

Dave,
The histogram on a digital camera nearly makes the original implementation of the zone system obsolete.  As I understood the zone system, it put numbers on the following concept: you explored various parts of the image, particularly the highlights and shadows, to see what would happen if you tried to capture them both within the range of zones available on your film.  Would the major items in the shot be too light or dark for your previsualized image, would you need to alter development etc, or would you need to sacrifice shadow detail or highlights, if there was too much range etc. (Not trivializing, just simplifying).
The available range in a single digital capture seems to be a matter of discussion and isn't simply stated, and has improved quite a bit as sensor and processor technologies have evolved.  It's probably beyond slide film, however.  Once you understand the histogram (together with bracketing/blending/HDR tools to extend the DR beyond a single capture) the need for the zone system per se goes away.  It's kinda built into a histogram.  In other words, the histogram IS the new zone system

I have a Sekonic for my 4x5 and when I got the 4x5, I religiously metered my shots as all the best books described (and the Sekonic graciously merged them into a single exposure recommendation which matched my own "placements")  I also used my Canon digital SLR to take shots of the same scene - adjusting the exposure based on the histogram to expose slightly less than what would have blown the highlights ("Expose right" in digital terminology).  Sheet after sheet I did this and there was rarely a difference of more than 1/2 stop and the trannies look great.  It was frequently "meter for the highlights and let the shadows fall where they may" - the latter being determined by the subsequent scan quality.  I will now only override the histogram if I know I want to sacrifice the highlights to get better shadow details (or vice versa)

If you can get you mind around the 2-dimensional distribution of tones in the image on the focusing screen and its transformation to a histogram of the same tones now ordered by luminance, you'll see that the histogram is simply the result of many millions of single pixel spot meter measurements, placed on a scale of the range available for capture - it's done all the work of gathering readings and placing them in zones (many 000's of them).  Only under severe conditions will you need to get the spot meter out to determine which particular blown highlights are in which location in the image.

I still carry, but only rarely use, the Sekonic. I think you'll find a histogram helps you implement the original ideas behind the zone system, only with more precision

Andy
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dbarthel

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Zone System for Digital Photography
« Reply #7 on: August 29, 2005, 01:12:59 pm »

The concept of the zone system on film was to either overexpose and under develop or underexpose and overdevelop to either expand or contract the image into 9 zones from pure black to pure white. While not directly relevent to digital, it is interesting to think of this if using the new CS2 exposure merge capability. You would spot meter your darkest parts with some detail and make sure they were at least 2 stops above black, and then for the brightest values, make sure that they were at least two stops below pure white. You now have zones 3 and 7 safely exposed. Then figure out how many intermediate exposures you need in one stop increments to go from the first to the last exposure. Then off to photoshop to combine all the images. (Ansel is rolling in his grave at this point  :D ). This does exactly what he did with chemicals - maximize the range with either compression or expansion.
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pcg

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Zone System for Digital Photography
« Reply #8 on: August 29, 2005, 05:09:31 pm »

If you still want to explore this further, you may want to look at some software by Reindeer Graphics (see http://www.reindeergraphics.com/). They make a PS filter that allows you to view the histogram as a classic zone values graph. I've found it interesting, & if I'm really stretching to pick up all the values between both shadows & highlights, I'll use it as a cross check. 'Worth a look. And I believe there may be a free download that's limited in time so that you can play w/ the software.
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Dan Sroka

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Zone System for Digital Photography
« Reply #9 on: August 30, 2005, 10:22:54 am »

Quote
While not directly relevent to digital, it is interesting to think of this if using the new CS2 exposure merge capability.
I agree. While the techniques of the zone system do not necessarily translate to digital, the lessons it teaches do. When converting a digital image to black and white, it is useful to think in zones, and assign areas of interest in the photo to appropriate zones.
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