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Old Feb 21, 2007, 5:01 PM   #1
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Quote:
...Even though it was perfectly sunny (as evidenced by the strong shadows)...
Mod Note:

I accidently pressed the Edit Button versus the Quote Button. So, instead of quoting you and replying to your post, I edited it.

My apologies. Feel free to repost the problem.

I'll repost my reply below.

Jim C.

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Old Feb 21, 2007, 5:47 PM   #2
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I'm not at all familiar with your equipment, but since you had it set on auto, I'll take a guess: the auto exposure tried to balance out the entire image to a satisfactory medium, to grasp as much detail as possible. The clouds are extremely bright, which skews the overall exposure reading (and makes the darker areas... appear darker). It's also backlit (the sun is behind your subjects), making them comparitively darker to the light areas in the photo.

To get around this when taking the photo itself, your best bet is probably to use spot or center-weighted metering on the foreground/non-light areas. This results in a good exposure of the people, but the sky will be "blown out" (flat white, little/no detail recorded at all).

In photoshop (or similar), you'll probably need to mess with levels (or curves) until you get a similar effect. You'll see a lot of lost detail, though. Best to get it right in the photo itself.
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Old Feb 21, 2007, 5:48 PM   #3
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If you look at the direction of those shadows, you'll see that your subjects were backlit (you were shooting into the sun).

A camera has a limited dynamic range (range of bright to dark that it can capture), and the metering system makes decisions on what needs to be properly exposed.

So, when you've got a lot of bright sky in an image (especially shooting into the Sun), that can fool the metering system.

It doesn't know that you want the people at the bottom properly exposed, versus all of that bright sky in the image. If it properly exposed the people, the sky would be too bright.

It actually handled it better than I would have expected. You can use a tool like the Fill Light feature in an editor like the free Google Picasa to quickly brighten them. Or, use a more sophisticated editor with features like curves, highlight/shadow sliders and more if you want to do even more.

In any event, if you're going to shoot into the sun like that, use Exposure Compensation.

Exposure Compensation lets you alter the way a camera's autoexposure/metering algorithms expose an image (brighten or darken it compared to the way the camera metered the scene). It's one of my most frequently used settings on most cameras.

A +EV value gives you a brighter exposure. The camera uses a slower shutter speed and/or larger aperture (smaller f/stop number) to get a brighter exposure, compared to what the camera's autoexposure/metering algorithms would have selected.

A -EV value gives you a darker exposure. The camera uses a faster shutter speed and/or smaller aperture (higher f/stop number) to get a darker exposure, compared to what the camera's autoexposure/metering algorithms would have selected.

If you're in Av Mode (Aperture Priority) and use Exposure Compensation, the camera will vary the shutter speed (since you're setting the aperture). If you're using Tv (Shutter Priority) mode and use Exposure Compensation, the camera will vary the Aperture (since you're controlling the shutter speed).

If you're in Auto (or other similar modes), the camera may vary aperture or shutter speed when you use Exposure Compensation. In low light, since your aperture is already wide open, it varies shutter speed if you use a -EV setting.

If you're shooting in Manual Exposure mode, there is no Exposure Compensation (because your aperture and shutter speed settings take the place of it since you're controlling both).

Correct Exposure comes down to the amount of light, the ISO speed, the shutter speed, and the aperture. A variety of combinations will produce identical exposure.
You use Exposure Compensation if you want a brighter or darker image compared to what the camera's metering would normally give you in the same conditions.

An example of when you may want to use a +EV setting is for a backlit subject, where the subject would normally be much darker than the rest of the image. Since the camera has a limited dynamic range, it doesn't know that you want the dark subject exposed properly (at the expense of the rest of the image). So, you can make the darker subject brighter for correct exposure (which might cause the rest of the scene to be overexposed some).

If your subject is much brighter than the rest of the image, you may want to use a -EV setting for Exposure Compensation so that your subject is not overexposed (making the rest of the image darker, too).

The camera has a limited range of bright to dark that it can capture. So, it makes choices so that most of the image is correctly exposed, depending on your metering mode. Sometimes that may not be what you want. That's where exposure compensation comes in.

I also see that you had your camera in Matrix (a.k.a., Pattern, a.k.a., Mult-Segment) Metering mode. That metering mode is designed to look at the entire scene and try to make a "best guess" as to what you want properly exposed.

Try Center Weighted Metering, too. Center Weighted metering places more weight on properly exposing what's in the middle of the frame, while still taking the entire frame into consideration. You may find that's it's more predictable, so that you don't need to use Exposure Compensation as much.

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Old Feb 21, 2007, 5:49 PM   #4
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JimC
D'oh, you beat me to it. Scratch my post, yours is better!
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Old Feb 21, 2007, 5:54 PM   #5
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I accidently edited the original post and was replying in it. So, you probably saw my reply in the original post (it was there for a minute or two before I realized my error).

That probably confused everyone.

My apologies.


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Old Feb 22, 2007, 9:53 AM   #6
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Thanks a lot for your explanations! I'm sure I won't make the same mistake again.
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