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Old Jan 7, 2005, 6:45 PM   #1
IDJ
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Hi,



I´m having problem to get a right flash - FE* - exposure with my 20D.

I had a Powershot Pro 1 that worked with TLL measure and no problem to compose a picture with FE*. Ex: somoneone in a balcony against the light - first I point the camrea to the landscapeand press the FE* , than I recompose the person in the picture and than press the shutter. In this way I get a nice fill flash picture whith a nice and well exposed landscape in the background.

But this procedurewith the 20D is not working, the picture appears over exposed because of the flash. I believe that this new TTl-II is the problem, because when I point to the landscape and press FE* my camera read also the distance and for that reason the flash over exposure the picture - the person is in focus, but the flash fire to iluminate the maximun distance...



Sorry for my english - I´m from Brazil - and thanks in advance for any help!




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Old Jan 7, 2005, 10:17 PM   #2
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You posted this in our Canon Forum, which is for Canon Consumer Models.

We also have aCanon EOS Digital SLR Forum, where you'll find forum members that will be able to help you better with your EOS-20D. So, I've moved this thread there.

I don't own your model, but it seems to me that the camera is working exactly the way it should. Flash Exposure Lock is designed to insure proper exposure of the subject that you locked on (what you are referring to as Landscape, and what I'll refer to as the background), not the foreground. So, I would expect that if you metered on the background andused FE Lock (*), then the flash would try tofire long enough to insure proper exposure ofthe background.

That's why closer subjects are overexposed (because you're telling the camera that you want the background exposed properly by using FE Lockwith it).

I'm sure Canon owners will correct me if my assumption is not correct.

It sounds to me like you'd need to use a larger aperture and/or slower shutter speed if you wanted more ambient light exposure in the background (or just increase ISO speed). Then, use the flash as normal (without FE Lock), unless your subject was not what you want properly exposed by flash.

Of course, you need to be careful not to slow down shutter speeds too much. Otherwise, you could get some motion blur from ambient light exposure.
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Old Jan 7, 2005, 10:23 PM   #3
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FYI - http://www.stevesforums.com/forums/v...20&forum_id=37

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Old Jan 8, 2005, 12:55 AM   #4
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The following link is to a reference that is a big help:

http://photonotes.org/articles/eos-flash/

"Canon EOS cameras always default to fill flash mode when the camera is in Tv, Av and M modes. They also perform fill flash in P mode if ambient light levels are high enough. There's no separate switch or pushbutton to engage fill flash."

Also read page 149 of the 20D manual about AE lock.

Would seem to me that if you were in Tv, Av or Man, you woulduse AE lock while pointing the focus point on your subject, not the background. The camera (or you in Man) would adjust shutter speed/aperature for the background and the flash would brighten the subject. Do I have this wrong (I'm a rookie)?



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Old Jan 10, 2005, 12:13 PM   #5
IDJ
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Hi JimC,

First thanks for your help.

But my question still remains, the procedure that I discreibed woked verywell with my old PRO 1 and don´t works whith my 20D...what I want to know is if there is some fast and praticle procedure to do the same with the 20D ?

Again, what I used to do was point to the landsape and press the FE* , than recomposeto the main subject and than take the picture...always worked very well, the landscape appeared very nice - colors and light - and the main subject with a fill flash well exposed. Like the example.

Thanks one more time.
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Old Jan 10, 2005, 12:14 PM   #6
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Just another example...
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Old Jan 10, 2005, 4:52 PM   #7
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IDJ wrote:
Quote:
Hi JimC,

First thanks for your help.

But my question still remains, the procedure that I discreibed woked verywell with my old PRO 1 and don´t works whith my 20D...what I want to know is if there is some fast and praticle procedure to do the same with the 20D ?

Again, what I used to do was point to the landsape and press the FE* , than recomposeto the main subject and than take the picture...always worked very well, the landscape appeared very nice - colors and light - and the main subject with a fill flash well exposed. Like the example.

Thanks one more time.
Well, you'd have to post a sample of one that didn't work well from the EOS-20D, so the differences would be more apparent.

Chances are, the only reason you didn't get an overexposed foreground (the problem you're describing for your EOS-20D photos) inthe samples you posted, is because the background is bright.

When you meter onthe brighter background,your Pro 1 flashwould have been contributing less to the exposure.

From what others are posting, how the EOS-20D works with metering depends on what mode you're shooting in.

So, the way you'd want to use the camera would depend on the lighting and what you are trying to accomplish, with your metering settings (center weighted, matrix, etc.), and where you use AE/FE.

I don't own this model, but it sounds likethe * button is in fact FE (Flash Exposure) versus AE lock, depending on what mode you're in. Perhaps Canon owners can let you know how this works if it's not explained in your owners manual.

You wouldn't want to use Flash Exposure lock if metering on the onthe background versus your subject. Thiscould result in either underexposed or overexposed photos from the flash -- depending on whether your background is darker or lighter than your subject.

If you want your subject properly exposed with flash, you'd want tomake sure you're metering your subject for flashpurposes. As far as the background being properly exposed, that would depend on whetherit was brighter or darker as to the desired settings.

For example, if your background was darker, you'd want to use settings that let more ambient light into the exposure (slower shutter speed and/or larger aperture and/or higher ISO speed). But, if you're in a darker area, you'd have to make sure shutter speeds weren't too slow. Otherwise, you could get motion blur from ambient light exposure. That wasn't the case in your samples.

Looking at the other thread that Forum Member NHL posted a link to above, it sounds like you can use a creative mode (Aperture Priority, Shutter Priority, etc.,) and the camera will expose for the entire scene (based on your metering mode I'm sure).

timmyB wrote:
Quote:
The 20D exposes differently for flash photography foreach mode setting (ie Av, M, P etc), and this is explained at the above site in detail:

"In Av, night and Tv (shutter speed priority) modes the camera meters for ambient (existing) light and fills in the foreground subject using the flash. It does not assume that the primary light source is the flash, and therefore the shutter speed it sets is the same as it would set if you weren't using flash at all.
http://www.stevesforums.com/forums/v...mp;forum_id=37

I'd suggest looking at your camera settings for photos you take that you're having problems with (look at the EXIF information in the image files, using an editor).This will give you an idea of how your camera behaves in different modes.

If you don't have an editor that can see these settings, download Irfanview from http://www.irfanview.com (it's free). Make sure to download the free plugins, too. You'll find your camera settings under Image, Information, EXIF.

Chances are, in some of the Auto Modes, it's fixing some of the Aperture and Shutter Speed settings to values that may not allow enough ambient light exposure. This may or may not be desirable, depending on the lighting. So, you'll have to use other modes to accomplish the desired result.

In any event, youdon't want to use Flash Exposure Lock while metering onsomething other than your subject, unless you have a specific objective in mind.

For example, you know that the brightness of the background is close enough to the brightness of your subject, so that you're not going to get an overexposed or underexposed subject as a result.

The fact that the camera may be taking distance information into consideration when metering this way, would be yet another reason you wouldn't want to do what you are trying to do (use Flash Exposure Lock on your background).


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Old Jan 11, 2005, 7:10 AM   #8
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Hi IDJ,

I think the best thing for you to do is to post the picture as well as all the settings you were using when taking the shot. I find it diffuclt to say what went wrong with the info you have given. There are many variables herewhich will effect the way the camera behaves.

style="BACKGROUND-COLOR: #000000"









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Old Jan 11, 2005, 9:12 AM   #9
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Guys

The camera's metering work best (just like any meter) when measured against a grey card!

Flash is no different :idea:

You can do FEL* lock all day as long as the 'subject' is not neutral grey you're not going to get the desired output!!!
... ie try to FEL* on a bride's white wedding dress (and then a groom's black tuxedo)

http://www.stevesforums.com/forums/v...20&forum_id=37
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