SLIDE 1
The Art, Science and Algorithms
- f Photography!
Exposure & Metering! CSCI 4900/6900! Maria Hybinette!
1!
Outline: Metering!
- What makes metering hard? !
– the meter doesn’t know what you’re looking at !
- histograms !
– Rule of thumb!
- metering technologies !
- metering modes (center, evaluative,...) shooting modes
(Av, Tv, P , M) !
- exposure compensation!
- background topics !
– Ansel Adams’ zone system! – Zone system and digital photography!
- Quiz!
2!
Quiz: Metering!
- 1. On Auto: you metered black on black (BB), white on white
(WW) and grey on grey (GG): How did the images differ?!
- 2. For black subject on white background (WSWB), Which
metering from (1) worked best?!
- 3. For a white subject on a black background (WSBB) Which
metering from (1) worked best?!
- 4. Assume you had reading available from (BB), (WW) and (GG)
but now your meter is broken:!
a) For a black subject on a white background (BSWB) how would you expose your image? [you can still adjust shutter and aperture)! b) How about a white subject black background?!
- 5. Suppose you did not have a metered reading for (GG) but only
for BB and WW, how would you now expose BSWB and WSBB?!
3!
What Makes Metering Hard?!
- light meters are not magical they don’t know
what you are looking at & what you want.!
- so they assume the scene is “middle” gray
(18% reflective) [12%-14%]!
- the world is full of hard metering problems...!
4! 5!
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6!
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