20D Fill Flash Overexposure

[tmumolo]

My experience with the 20D and new ef-s 17-85 lens, using either the on board flash or 420ex flash, is a bias toward over exposure. For some reason, and I can't figure this out, it happens more at wider focal lengths.
This applies to three differant bodies I'ver tried.
I've done numerous tests and the results are the same. This applies to outdoor flash "only" It requires anywhere from 2/3 to 1 full stop of negative FEC to get acceptable results.
No problem with indoor flash or ambient exposures.
Anyone have similar experience? I talked to Canon and they said to wait and see if I have the same problem using the new 580ex which I have on order.
This is a bit confusing since I have the same problem with the on board flash and ETTL 2 is promoted as being compatible with all EX series speedlights.

[Malaxos1]

No problems here. In what mode do you shoot? I use M mode all the time. Anyway, I have a 20D and 420EX, I shot a wedding a wekk ago and used fill flash out side without any problems at all...Dean

[slin100]

Flashes have a minimum working distance. Overexposure can happen if you are too close to the subject. At wider focal lengths, you might be stepping in too close to fill the frame.

Did you disable auto reduction of fill flash (C.Fn 14 on a 10D, not sure if it's the same on a 20D)? If so, flash will default to FEC 0 when outdoors in bright light.

What mode was the camera in? Av, Tv, M, P? If in Av, you may have been bumping up against the 1/250 sync speed and overexposing the entire frame. With a 420EX this can be overcome by enabling high-speed sync.

[abel]

i have a question... i have a 10d and a 550ex.

in order to use it as a fill flashh do i just snap it on and set it to ETTL? or is there something else i have to do in order to set it to FILL?

sorry for the newbie question but i have never really taken the time to sit down and read up on flash techniques etc... much less the manual... hehee

[scottbergerphoto]

i have a question... i have a 10d and a 550ex.

in order to use it as a fill flashh do i just snap it on and set it to ETTL? or is there something else i have to do in order to set it to FILL?

sorry for the newbie question but i have never really taken the time to sit down and read up on flash techniques etc... much less the manual... hehee
The 10D is set to give an automatic reduction of fill flash in bright ambient light, unless you disable it in Cfn's. Personally I prefer to disable it and dial in my own of -1 to -1 and 2/3 FEC for fill flash. I get more consistent results that way.
Scott

[robertwgross]

... This is a bit confusing since I have the same problem with the on board flash and ETTL 2 is promoted as being compatible with all EX series speedlights.

The word "compatible" has many different degrees ranging from "You can slap these together without them blowing up" to "Perfectly equivalent."

---Bob Gross---

[tmumolo]

Thanks for the input.
I'm not shooting closer than minimum distance
I do not have evaluative flash mode disabled
I wasn't so much looking for a fix as I was interested if this was a common experience or just a bad camera.
as far as the word compatible is concerned: Viewed in context, it should be obvious what is meant. As a matter of fact Canon uses the that word in the same way. :0)
My interest in the 580ex is primarily because it takes a direct high voltage connection for my Tubo Z power pack and because of it's enhanced digital capabilities as opposed to my 550ex, which I sold.

[scottbergerphoto]

The 550 has a high voltage connection for Turbo/TurboZ batteries as well. I am not convinced that the new technology added to the 580 is going to make a difference in quality of results.
Scott

[tmumolo]

As a matter of fact I'm not "convinced" the 580ex will deliver superior results but since it is optimized for digital (designed from the gound up) i.e. white balance correction-sensor size recognition-.03 stop flash accuracy etc. I felt it would offer advantages.
Granted these are subtleties but as we see digital photography mature, these refinements as an aggregate are designed to deliver an optimum result. Take for granted the optimized digital lens, which has modified multicoating to neutralize kick back reflections from a shiny image sensor. Small refinements but welcome non the less.
tony