bob-
i'm not sure how much you know about light metering...lots of books out there (Ansel Adams' The Camera is a great one) that can explain it better than I can. here's the basic deal:
a camera's meter evaluates exposure as if it's looking at 18% grey (one thing...understand that i mean 18% grey in terms of brightness, obviously it's not changing colors around on you). if you were to meter a tiny spot in a dark shadow and use that exposure, then in your pictures, that spot would have a brightness equivalent to medium grey, and the sunlit spots would be blown out highlights. on the other hand, if you were to meter a tiny spot in one of the sunlit spots, in the final image that spot will be a medium grey, and the shaded areas will be extremely dark.
with that said, please understand that the dreb does not have a 'spot' meter. in general, the dreb evaluates the entire frame (evaluative metering), does some magic AI stuff, and arrives at an exposure. most of the time for most images, it's correct, but not always...images of shiny cars in bright sunlight might throw it off.
because the camera isn't always right it's nice to have more control over the exposure. this does mean that you will have to think more about what you're doing. if you don't want to think about it, let the camera do it and hope for the best...
to have more control over the exposure, you need to limit what the camera's meter is "seeing" when it evaluates exposure. there are a couple ways of doing this...the old school way: fill the frame (either by zooming in or by moving yourself) with something that you want to end up being 18% grey, take an exposure reading and determine the aperature (Av) and shutter speed (Tv) you want, recompose your shot and then take the picture using the Av and Tv you've just determined.
with the dreb, there are a couple other work arounds...
using the * button meters a small area around the current focus point (partial metering): focus on an area you want to end up being 18% grey, hit the * button to lock this exposure, then recompose, refocus and take the picture.
using Manual mode meters exposure for the area around the center focus point (center-weighted metering). because you will dial in the Av and Tv yourself, you can then recompose, focus and shoot.
finally, by choosing a specific focus point, the camera
appears to use partial metering around that focus point....i stress "appears" because neither the manual, nor phil's review, indicate that this is the case.
did that make
any sense? as i said to start with, there are lots of books that explain it better than i can (plus have the advantage of images and examples). if it didn't, reply to me and i'll try to make it a bit more straightforward.
(incidentally, if you hear people talking about 'grey cards', they're referring to pieces of cardboard that are quite literally grey - in this case, exactly 18% grey - that are used to help accurate meter a scene. )
oh yeah, and if i didn't say it before, shoot raw so that you can pull more details out of the shadows...
the great thing about shooting digital is that you can look at your image and histogram immediately to see if you've captured what you wanted...
sorry i got so longwinded; like i said, if i doesn't make sense, please let me know, i'll try again.
good luck,
jim.
Jim/Mike---Thanks for the input!
Jim-you said there are a number of ways around the strong contrast
between the sunlight and shadows. Can you point me in the right
direction here.
Is one way to use only the center square for focus (vs all 7 focus
points)....or I believe I read something about average metering?
-Bob
