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Old Sep 28, 2005, 8:24 PM   #1
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Hello, I am not sure what I am doing wrong, but it seems that from time to time I get dark pics when shooting outdoors, I usually use the full Auto mode, Any idea what could be wrong? thank you!
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Old Sep 28, 2005, 9:31 PM   #2
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You may want to post a specific example here that members could comment on. Is the entire photo darker (or are some portions like a bright sky properly exposed)?

Even though you're shooting in Auto mode, a camera can't always know what it should properly expose.

You have a limited dynamic range with a camera (ability to capture both brighter and darker areas if there is too much difference between them). So, if you have very dark and very bright portions of an image, you either have to properly expose one or the other (or go somewhere in the middle).

There are also techniques to improve the images later in software using an editor, and you can even blend two photos taken at different camera settings together later (one taken with settings to properly expose the highlights, and another taken with settings to properly expose the shadows). Using raw will allow youmore latititude in this area, too. Many editors allow you to adjust shadows and highlights separately later for better results, too .

It's best to err towards underexposure to keep from losing too much detail in the brighter portions (since you really won't be able to recover the detail using an editor once they are overexposed too much, causing what you'll see referred to as "blown highlights").

You may even want to use a Graduated Neutral Density Filter for some scenes. They are designed to block some of the light as you get higher or lower on the filter (depending on how it's rotated). These can come in handy where you want a properly exposed sky (letting it block some of the light), while still properly exposing the rest of the image that is not as bright.

One common example of when you may get underexposure is whenyoutake a photo ofsomeone standing with the light coming from behind them (backlit subject). Using the default settings,the background may lookit should (trees, landscape, etc., are properly exposed), yet the subject is dark (in shadows) compared to the rest of the image).

The camera is more sensitive to those kinds of changes in light compared to the human eye.

If the camera tried to properly expose the backlit subject, then the background may be overexposed.

The camera doesn't know that you want the darker area exposed properly (at the expense of improperly exposing the rest). So, it has to make a decision on what settings (aperture, shutter speed) to use. Depending on your metering mode, it may be taking the entire scene into consideration, or it may be placing more weight on the portion in the center.

But, when scenes require a camera to capture scenes with very dark and very bright portions (where there is a lot of difference between the bright and dark portions), you have limitations to contend with.

That's a relatively basic example. But, you need to understand exposure and metering (and the dynamic range limitations of your camera) to correct for those situations (or improve them as best as possible).

One way to handle the example above (backlit subject that's muchdarker than the rest of the image)is to use Exposure Compensation (setting it to a +EV Value, which tells it toexpose the scene brighter than the Autoexposure normally would).

Another way to handle it (if your subject is close enough) is to use fill flash.

Knowing when you need to use Exposure Compensation or a different metering mode comes from more experience with your camera, so you have a better understanding of how it's going to behave in given conditions. You'll need to learn to look for those types of things in a scene and adjust accordingly.

You may also want to try and find a book on basic photography that can help explain exposure and metering.

Again, if you can post a samplehere, I'm sure Canon owners could probably give you some tips on what went wrong for a specific photo. Your camera also has a histogram that can be useful for judging exposure when you take a photo to see if you need to make some changes in your settings.





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Old Sep 28, 2005, 9:45 PM   #3
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Thank you for your help, here is a sample pic that was taken by aCanon Rebel cam, (inAuto mode), you can see that the pic is too dark and the subject's face isnot clear enough, this does not happen all the time, but I amnot sure what couldcause thator what canI doto prevent such pictures. Thank you!
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Old Sep 28, 2005, 10:11 PM   #4
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One reason I picked the example I did is because it's probably the most common cause of a problem when users complain that sometimes a photo is underexposed outdoors (backlit subject).

If you start reading my lastpost, where I mentioned a backlit subject, this applies to your photo:

Quote:
One common example of when you may get underexposure is whenyoutake a photo ofsomeone standing with the light coming from behind them (backlit subject). Using the default settings,the background may lookit should (trees, landscape, etc., are properly exposed), yet the subject is dark (in shadows) compared to the rest of the image.

Note how the background in your photo (sky, trees, fence where sun is hitting it) is exposed properly. The metering needed to make a decision on what settings to use. It properly exposed the majority of the image. It can't capture a scene with that much difference between dark and lighter areas without overexposing the brighter area if you want to properly expose the darker area (your subject that's in shadows).

Read the rest of mypostwhere I mentioned using Exposure Compensation set to a +EV Value, or using Fill Flash if the subject is close enough.

If you use Exposure Compensation set to a +EV Value, guess what is going to happen to the background? The sky will be brighter (probably white if you properlly exposed your subject),and the trees will be overexposed, with the area of the fence in sun overexposed to the point of losing all of the detail (blown highlights).

Fill Flash would have been a good thing for this one since your subject appears to be very close (that way, you're making your subject brighter so that there is less difference in brightness between your subject and the rest of the scene).

Play with your camera's settings (like Exposure Compensation), taking the same photo using different settings so you'll know what it does and how much to use.

You'll see how to use Exposure Compensation in your manual.

Learn to look for lightinglike you see here (whereyour subject is much darker than the rest of the image),so you'll know when to make some changes (keeping in mind that the camera may not be able to properly expose everything, so you may need to compromise).

Also take a look at metering options (for example, your camera has a Center Weighted metering mode that places more emphasis on properly exposing what's in the middle). Again, if you properly exposed the subject here, then much of the image would have been overexposed.

The camera did what it was supposed to (it can't read minds, so it didn't know that you wanted the darker portion exposed properly (which would have overexposed the rest). You'll have to tell it when you want something different (learning to look for these types of conditions), and using different metering, exposure compensation and even your flash as fill.

This is a good example of where fill flashwould have been a good solution to make your subject brighter,so that there would not be as much difference inbrightness compared to the rest of the scene.

A book on basic photography may also be helpful in understanding the concepts of exposure (and it doesn't necessarily need to be specific to Digital Cameras)


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Old Sep 28, 2005, 11:46 PM   #5
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This is Great, thanks for your help JIMC, I will look into getting a book to get more info about this issue.
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Old Sep 29, 2005, 12:04 AM   #6
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With practice, you'll develop an eye for lighting, so you'll have a good idea of when you need to do something differently compared to what the cameras's autoexposure algorithms would do. Again, in some conditions, you may have to compromise (you may not be able to get everything in a scene exposed properly., so you'll need to make decisions on what is more important in a scene and/or use an editor to try and improve it later by brightening up some areas).

If you don't understand something, just ask here. I'm sure the forum members would be happy to give you some tips. Ditto for helping to improve your photos with an editor.

All of us are still learning (it's a never ending process), and some input is required before the camera can give you the best results (Auto doesn't always work well in all conditions, and you sometimes need to be smarter than the camera to get the results you want).


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