Digital Zone System with Canon Eos G3

"One of the easiest-to-understand books on exposure and the Zone System that we've ever seen"

Outdoor photographer Magazine

If you do not want to read the book titled "the confused photographer's guide to photographic exposure and the simplified zone system ISBN: 0966081714" simply read the following:

The on-camera or off-camera spotmeters (spot meter) are the most powerful exposure tool in the world. However, before you can use them you must have a basic understanding of the Zone System of light measurement. Read the following page and decide for yourself if you understand the concept. If you do understand everything, and you can apply the technique described, then that is all you need (well almost!)
If, however, you even have the slightest doubt about this technique, or if you are still the least bit confused, the confused photographer's guide to photographic exposure and the simplified (non technical) zone system is for you.
I believe this is the simplest, easiest, best illustrated, and most practical book about the photographic exposure, the simplified zone system (non-technical), incident metering and off-camera spotmetering in the world. To see more of the book and what you will be learning, please browse:

http://www.simplifiedzonesystem.com

or send an e-mail to
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Cheat sheet: The entire book condensed onto one page (well almost!) To see what is exactly covered, please see the Appendix at
the Simplified Zone System book
(Based on Farzad's 5-stop Film / Digital zone system Š1987-2005)

Set the ISO of your Canon G3 to 100 and choose an outdoor subject. Activate the spotmetering option on your camera and set your camera’s mode to manual and to the shutter speed to 1/250 sec.

Observe your subject and break it down into its simple subject (single toned) components. Choose a Reference Tone. A Reference Tone is usually chosen from the most important part of the subject. Once you have selected the Reference Tone, point your spotmeter at this tone and find its normal exposure. If your subject does not have a distinct single tone, pick out a tone that is medium gray or brighter

Let’s assume the "normal exposure" indicated by your camera for this Reference Tone is 250@f-8 (i.e., 1/250 sec. at an aperture setting of 8). If you can set your 990 to an aperture of exactly f-8, simply play with the zoom/wide-angle setting of the camera and you will.
As you may know, the spotmeter’s "normal exposure" from any simple (single toned) surface will always provide the photographer with an 18% MEDIUM GRAY image tone (about 128 on the grayscale value of '000' to '255' on your monitor- please see the illustration below). Please note that in your version of Photoshop, the 18% may not appear on the bottom right hand side but it is important to notice the semi-circle on the left is located exactly in the middle of black and white.

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The image tone that your normal exposure provides is independent of the original tone of your subject (you must understand this!) The following is an illustration:

In spotmetering, converting the "normal exposure" to the "correct exposure" is what a photographer must do. In other words, the "normal exposure" readings of the spotmeter must be interpreted by the photographer to determine the subject’s"correct exposure." The principle behind this simplified technique is that if one tone of a complex subject is exposed correctly, the rest of the tones follow and will also be correctly exposed . Now decide which one of the following tones would most closely matches your Reference Tone: Black, Dark Gray, Medium Gray, Light Gray or White. With this simplified technique you must choose one of these five tones. Once you have decided which one of these five tones best matches your Reference Tone, then adjust your camera settings accordingly:

If you chose Black, you need to decrease the "normal exposure" setting by two stops. Decreasing the exposure time by two stops converts the 18% gray image tone to Black. The correct exposure is now 1/1000 @ f-8 or equivalent. In Grayscale value it is approximately 028 out of 000-255 scale on your monitor.

If you chose Dark Gray, you need to decrease the "normal exposure" setting by one stop. Decreasing the exposure time one stop converts the 18% gray image tone to Dark gray. The correct exposure is now of 1/500 @ f-8 or equivalent. In Grayscale value it is approximately 078 out of 000-255 scale on your monitor.

If you chose Medium Gray, leave the aperture and shutter speed as they are
(1/250 @ f-8) since the meter is already creating an 18% gray (Medium Gray) image tone, i.e., the tone of the image matches the approximate tone of the Reference Tone. Also remember that when metering from a medium gray surface, the "normal exposure" and "correct exposure" settings are approximately the same. In Grayscale value it is approximately 128 out of 000-255 scale on your monitor.

If you chose Light Gray, you need to increase the "normal exposure" setting by one stop. Increasing the exposure time by one stop converts the 18% gray image tone to Light Gray. This results in a correct exposure of 1/125 @ f-8 or equivalent. In Grayscale value it is approximately 178 out of 000-255 scale on your monitor.

If you chose White, you need to increase the "normal exposure" setting by two stops. Increasing the exposure time two stops converts the 18% gray image tone to White. The correct exposure is now 1/60 @ f-8 or equivalent. In Grayscale value it is approximately 228 out of 000-255 scale on your monitor.