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Old Oct 24, 2006, 8:06 PM   #1
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first post-
i searched for this topic before posting, but i couldnt find anything-- sorry if it has been discussed previously.

anyway, i'm looking for a relatively small (ie. sony cybershot w70) camera (around 5megapixel or greater) that can be set to automaticaly bracket shutter speed. basically, i want to take a series of photograps with the following settings or similar with one push of a button: -6EV, -4EV, -2EV, metered EV, +2EV, +4EV, and +6EV. a cable remote or wired/wireless remote with shutter button would also be helpful, but not a dealbreaker. im not sure where i can find this information, any help is appreciated.

thanks in advance.
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Old Oct 24, 2006, 10:48 PM   #2
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sjd753 wrote:
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basically, i want to take a series of photograps with the following settings or similar with one push of a button: -6EV, -4EV, -2EV, metered EV, +2EV, +4EV, and +6EV. a cable remote or wired/wireless remote with shutter button would also be helpful, but not a dealbreaker. im not sure where i can find this information, any help is appreciated.
Why would you need to bracket with that large of an exposure range?

No camera that I know of, small or large, is going to let you set 2 EV steps for bracketing, unless I missed one somewhere. Most models with exposure bracketing are limited to anywhere from 0.3 to 1 EV steps, not 2 EV steps.

Depending on the model, you usually get from 3 to 5 shots (or some are selectable) for bracketing. For example, if the camera allowed you to bracket in 1 EV steps (and many models are limited to bracketing in -0.3 or -0.5 EV Steps instead) with 5 photos, you'd get get exposures at -2 EV, -1 EV, 0 (as metered), +1 EV, +2 EV

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Old Oct 25, 2006, 11:08 AM   #3
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Actually I have a question about this...

Is changing the EV setting in-camera much different than changing the brightness setting in basic photo editing software?
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Old Oct 25, 2006, 11:12 AM   #4
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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.

If you reach the camera's ISO speed limits and your shutter speeds are still slower than desired, you can also use exposure compensation to get faster shutter speeds by deliberately underexposing using a -EV Setting. Then, brighten the images later using software so that they appear to be correctly exposed.

But, this will increase noise levels, just as if the camera had an even higher ISO speed available (especially after you brighten the underexposed images with software), and deliberately underexposing and brightening images later also results in some loss of dynamic range. So, don't use this technique unless you have to.

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Old Oct 25, 2006, 11:19 AM   #5
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This is an excellent explanation. I appreciate it and will try to start using exposure compensation as need be. You should make this post into one of the stickies at the top of a forum. It has been most helpful!
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Old Oct 25, 2006, 6:20 PM   #6
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@JimC
Thanks for the response.

>>Why would you need to bracket with that large of an exposure range?

You're right. I don't need such a large exposure range. I have been playing around with a DSLR with various shutter speeds and bringing them together with software to get some high dynamic range (HDR) images that are quite trendy these days. The problem is, this camera is far too large and expensive to take with me as I backpack through Europe in the coming months. I would like to take pictures of my travels and return home with images that I can merge to HDR.

>>Most models with exposure bracketing are limited to anywhere from 0.3 to 1 EV steps, not 2 EV steps.

Any small/compact models allow this? If so, can anyone name a few or offer suggestions on a model they life?

>>Depending on the model, you usually get from 3 to 5 shots (or some are selectable) for bracketing. For example, if the camera allowed you to bracket in 1 EV steps (and many models are limited to bracketing in -0.3 or -0.5 EV Steps instead) with 5 photos, you'd get get exposures at -2 EV, -1 EV, 0 (as metered), +1 EV, +2 EV

Do you know which models offer 5 shots and which can bracket in 1 or even .5 EV steps?

Thanks Again


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Old Oct 25, 2006, 6:54 PM   #7
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The first thing that came to mind, is that you were probably wanting to bracket to use some of the latest and greatest software (or techniques) to create HDR images. lol

I use bracketing mostly in rapidly changing lighting conditons (for example, live music where stage lighting is constantly changing and you don't have the luxury of time on your side to get the exposure just right).

Unfortunately, I don't know of a good way to narrow down your choices, other than reading through the reviews of models that meet your other needs (size, weight, resolution, ISO speed range, focal range, etc.), and see what the specs show for bracketing, looking at the menus in the reviews to see what the options are (you'll find sections in our reviews that show most of the menu options).

I don't keep up with the newer digicam models as much as I once did. So, this is something that I haven't paid much attention to (bracketing capability is not usually something most buyers of compact digital cameras look at).

I did glance though the Best Cameras List yesterday and noticed that the Coolpix 7900 has bracketing capability. But, we didn't cover all of the available options in the menus, and I haven't taken the time to track down a user guide to see it's limitations yet..

That's probably the route that you'll need to take.... looking through the specs and record menu options in the reviews for models that meet your other criteria, then visit the manufacturer's web sites and look through the user guides to see any detail that wasn't covered in the review.

The Nikon models like the Coolpix 7900 would probably be a good place to start looking, since it looks like most of the smaller camera models from Canon left out bracketing ability.

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