Help with flash exposure needed...

Started Aug 6, 2012 | Discussions thread
Zec_
Forum MemberPosts: 51
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Re: You need to set the 380EX for High Speed Sync.
In reply to Lemming51, Aug 7, 2012

since the images are so overexposed, it is hard to see but the scene is actually taken in afternoon shade with sunbeams here and there - I did not think the auto iso 400 was too much...

Your answer makes sense - I will have to try HSS, disable auto ISO and see what happens... actually your answer prompted me to remember a fantastic article that describes the same thing: http://photonotes.org/articles/eos-flash/#fp

the 380ex is a e-ttl II flash, and canon states it is fully compatible with 1000d. I am inclined to think I am doing something wrong - rather than the equipment is faulty...

In the article mentioned, I understand that EOS cameras always default to fill flash mode in Tv, Av and M - and also in P mode if ambient light is fairly bright ("above 13 EV")... otherwise in P mode flash is supposed to expose correctly the subject and leave the background as it turns out...

so why is there no difference in my photos in Av i P mode in afternoon shade setting - is it possible it is too bright? also I am 5m or so from the subjects - is it probable the flash x-sync is too great for outdoor flash use? would taking 2 pictures with flash exposure compensation of 0 and -2 stops answer this question?

thanks for your help!

Lemming51 wrote:

In normal flash the shutter speed is limited to 1/200, the x-sync speed. For outdoor fill flash in sunlight (like your sample pics) that lets in too much light for the aperture set in Av, or in P the camera may not be able to set a small enough aperture to compensate.

Set the 380EX for High Speed Sync so that shutter speeds of up to 1/4000 can be set with the flash. (note, HSS is not available when using the built-in flash.

Also check that you have not set Auto ISO. With flash, AUTO ISO defaults to 400, which is much higher than necessary in sunlight.

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