If you do not want to read the book titled
"the confused photographer's guide to on-camera spotmetering (spot metering / partial
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 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!)
Put a roll of 100 ISO Slide
film in your Nikon N70 (n70) 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 book we will increase and decrease
the exposure by opening-up and closing-down the aperture. The shutter speed will remain
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 may 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. It is extremely important that you
understand this point. 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 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 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 firstname.lastname@example.org.
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