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Old Nov 2, 2006, 1:03 PM   #11
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NHL wrote:
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IMO there's nothing wrong with this camera - try the FEL button (Flash Exposure Lock) on a more neutral part of the subjects. :idea:
-> Most cameras are set to expose on neutral grey only... and try to understand how the evaluative metering work (it's not as smart as your brain)
I can understand where RJR and Jon S are coming from. I have similar problems in difficult lighting situations with my 30D. Indoors I use "M" setting with speed at 1/125 or 1/60. Aperture setting is 5.6 or 8.0 with spot metering. Even thenI use FEL button most of the time to insure area of interest is properly expose.

I have not tried "evaluative metering" in this set up and I don't know if it would be better? May be NHL can shed some light on it (pun intended:-)).
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Old Nov 2, 2006, 5:07 PM   #12
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You're quite correct - the best way to use flash is with the camera on manual and the flash on automatic!

When FEL is pressed, the pre-flash is fired and the camera lock in the exposure value based on the center weight area where the camera is pointed to - It depends on the camera, but I'm pretty sure the evaluative metering is no longer used with the FEL button - One can be quite selective in this mode since the camera will ignore most of the bright(or dark) backgrounds.... not in the areas of interest
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Old Nov 2, 2006, 5:26 PM   #13
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I have a digicam but can't you force the flash to fire, When taking pictures with a bright window the flash will not flash on auto so I use program mode and turn the flash to fire.
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Old Nov 2, 2006, 6:42 PM   #14
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NHL wrote:
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You're quite correct - the best way to use flash is with the camera on manual and the flash on automatic!

When FEL is pressed, the pre-flash is fired and the camera lock in the exposure value based on the center weight area where the camera is pointed to - It depends on the camera, but I'm pretty sure the evaluative metering is no longer used with the FEL button - One can be quite selective in this mode since the camera will ignore most of the bright(or dark) backgrounds.... not in the areas of interest
I have a few more questions on Flash photography butI don't want to hijack this thread. I will start a new one. What would be a better forum for that?
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Old Nov 2, 2006, 8:24 PM   #15
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harana wrote:
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I have a few more questions on Flash photography butI don't want to hijack this thread. I will start a new one. What would be a better forum for that?
Over here: http://www.stevesforums.com/forums/view_forum.php?id=53
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Old Nov 4, 2006, 1:41 PM   #16
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I was notified by Canon the the exposure system used is different when FEL is enabled as compared to "straight" shooting with an external flash. That is why the images come out brighter with FEL enabled. You can go into the custom functions menus and change the default flash metering system used.

You can choose between evaluative (default) or average. I need to change my setting to average and test it.

Interestingly, when i take a shot of an image with a wall behind, it comes out okay. if the wall is angled just a bit, the whole image gets darker. i also tried this on a 30D and was able to duplicate the problem.
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Old Nov 6, 2006, 2:29 PM   #17
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Well, after much browsing the internet, i have come across a must read regarding the E-TTL II the Canons now use for flash exposure. Photonotes.org (http://photonotes.org) has an in-depth article about Canon flash systems over the years.

Programmed Flash:
Program mode operates in one of two modes, depending on the ambient (existing) light levels.

1) If ambient light levels are fairly bright (above 13 EV) then P mode assumes you want to fill-flash your foreground subject. It meters for ambient light and uses flash, usually at a low-power setting, to fill in the foreground.

2) If ambient light levels are not bright (below 10 EV) then P mode assumes that you want to illuminate the foreground subject with the flash. It sets a shutter speed between 1/60 sec and the fastest X-sync speed (see above) your camera can attain. The aperture is determined by the camera's built-in program.

Because the camera tries to keep the shutter speed at a reasonable speed for handholding the camera you will end up with dark or black backgrounds if you take a flash photo in P mode when ambient light levels are not bright.

Tv (shutter priority) mode flash:
In this mode the camera lets you change the shutter speed. It then automatically chooses an aperture setting to expose the background correctly. Flash duration (flash output) is determined by the flash metering system. In other words, the camera always works in fill flash mode when it's in Tv mode - it always tries to expose the background adequately, unlike P mode.

Av (aperture priority) mode flash:
Av mode lets you set the depth of field by specifying the lens aperture. The camera then chooses a shutter speed ranging from 30 seconds to the camera's X-sync speed, in order to expose the background correctly. If that means the shutter speed is some really low value so that you need to use a tripod to avoid camera-shake blur, so be it. In dark conditions, therefore, Av mode works in slow sync mode.

Flash duration (flash output) is determined by the flash metering system. Like Tv mode the camera always works in fill flash mode when in Av mode.

I have played around with the various settings and found the above to be true. Also, by changing the custom function Fn8 (flash exposure metering) from evaulative to average will result in a more evenly distributed light level on the image.
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