The Partial Metering
technique for Rebel 2000
reader's review from amazon.com
If you do not want to read the simplified and slow-paced book titled "The confused
photographer's guide to on-camera spotmetering (spot metering / partial metering) ISBN:
0966081706" simply read the following:
The on-camera spotmeter (spot meter
/ partial meter) is the most powerful exposure tool in the world. Read the following page
and decide for yourself if you understand the concept. If you do
understand everything on the next page, and you can apply
the technique described and produce correctly exposed images, then that is all you need!
If, however, you even have the slightest doubt about this technique, or if you
are still the least bit confused, this descriptive and slow-paced book is for you.
Remember: either you know how to use your on-camera spotmeter effectively or you
dont. There is no in-between! I believe this is the simplest, easiest, best
illustrated, and most practical book about on-camera spotmetering in the world.
Cheat sheet: The entire book condensed onto
one page(well almost!)
(Based on Farzad's 5-stop Film / Digital Zone
Put a roll of 100 slide ISO
film in your Canon EOS Rebel 2000 camera and choose an outdoor subject. Activate the
spotmetering option on your camera and set your cameras mode to manual and to the
shutter sped to 1/125 sec. To avoid confusion, in this exercise we will increase and
decrease the exposure by opening-up and closing-down the aperture. The shutter speed will
Observe your subject and break
it down into its simple subject (single tone) 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 and you are using slide
film, pick out a tone that is medium gray or brighter. If you are using a negative film,
pick out a tone that is medium gray or darker.
Lets assume the
"normal exposure" indicated by your camera for this Reference Tone is 125@f-8
(i.e., 1/125 sec. at an aperture setting of 8).
As you know, the spotmeters "normal
exposure" from any simple (single toned) surface will always provide the photographer
with an 18% gray image tone. The image tone that your normal
exposure provides is independent of the original tone of your subject.
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 subjects"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. Closing- down the
aperture by two stops converts the 18% gray image tone to Black. The correct exposure is
If you chose Dark Gray, you
need to decrease the "normal exposure" setting by one stop. Closing- down the
aperture by one stop converts the 18% gray image tone to Dark gray. The correct exposure
is now of 125@f-11.
If you chose Medium Gray,
leave the aperture and shutter speed as they are (125@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.
If you chose Light Gray, you
need to increase the "normal exposure" setting by one stop. Opening-up the
aperture by one stop converts the 18% gray image tone to Light Gray. This results in a
correct exposure of email@example.com.
If you chose White, you need
to increase the "normal exposure" setting by two stops. Opening-up the aperture
by two stops converts the 18% gray image tone to White. The correct exposure is now 125@f-4.