Question Re: Canon EOS 30D

[PhotoDave1]

I just bought a 30D to replace my aged but venerable 10D and I am very pleased with the performance of my 30D but I noticed a potential problem a few days ago and I want to ask if anyone else has observed this.

As is the camera takes great photos in fact probably better photos than I am capable of. A few days ago I was taking some flash photos with my Canon 580EX flash and I noticed that all of the flash images are underexposed by a full stop. I found this out when I reviewed the imaged on the cameras screen and looked at the histogram.

I can correct for this by using the Flash Exposure Compensation function but I can't believe this is normal. The underexposure happens whether I am using the built in flash or my 580EX.

Is this a documented issue with the 30D? I know Canon rushed this body to market and did not do a good job of testing it and getting the bugs out of it and there are other well documented issues such as random full lockups but is the flash problem a documented issue and more importantly has Canon addressed this and issued a fix for it? Thanks.

[kgphoto]

Are you using TTL? If you are using TTL and you do not have the 580IIX then that is the problem. The first 580 was junk.

Secondly, are you sure all your settings are correct? IE both on the same ISO and exposure compensation settings?

Are you staying within the distance ranges that flash can handle?

These are the things I would look at first.

[PhotoDave1]

Originally Posted by kgphoto

Are you using TTL? If you are using TTL and you do not have the 580IIX then that is the problem. The first 580 was junk.

Secondly, are you sure all your settings are correct? IE both on the same ISO and exposure compensation settings?

Are you staying within the distance ranges that flash can handle?

These are the things I would look at first.

KG, thanks for your comments.

Yes all of the settings are right. I checked that when I first noticed the problem and I think I can pretty much rule out a setting discrepancy between my 580 flash and the camera because the underexposure also happens when I use the camera's built-in flash

Yes, I am staying within the distance range(s). Generally I try to pick a place in the middle of the distance range so as to give me a safety margin.

I do have the original 580 flash and it worked fine with my EOS 10D but as you commented maybe there are finite differences between the interface on the 580 flash/EOS10D combo and the 580 Flash/EOS30D combo.

I am able to compensate and get good exposures by using the Flash Exposure setting on the camera but it troubles me to see the flash exposure that far off.

Thanks again for the assist.

[kgphoto]

Weird that it involves the built in flash as well. I would read through the manual and then call Canon on their 800 number and see what they have to say. Then post here and tell us all about it.

The other thing I would do is calibrate your meter and cameras together and see if they are all producing the same image/exposure and EIFX data.