new to Canon digital and 550 EX

[bluedevil64]

I recently made the switch from Nikon to Canon..a Canon 1D, Eos3, and 550 ex flash. I liked the standard TTL on the Nikon SB-80dx which the 550 EX doesn't have, and I usually get somewhat underexposed photos indoors, especially with the EOS-3. Can someone offer tips for using the EX 550 and possibly suggest articles on the net which might help.

[Vegas Poboy]

Welcome to the world of Canon, hopefully this site will help http://photonotes.org/articles/eos-flash/. Other than that all I can suggest is to make sure all the camera settings are correct. I did a shoot a couple of weeks ago and had the same problem. I finally figured out I had the flash compensation 2 stops less that what it should of been.

[theoldmoose]

Make sure you don't have the 550EX set on 'master'. It needs to be on the first, or 'single' setting, rather than master or slave. If you read the 550EX manual, someplace in there they explain that setting the 550EX on 'master' automatically sets a flash compensation of -1 stop.

I didn't catch this at first, and had just set the switch to master, figuring it wouldn't harm anything. Most every shot I took on that setting was almost exactly underexposed by 1 stop.

Fortunately, I was shooting in RAW mode, so I was able to salvage the shots after the fact.

Have fun with your new gear.

[robertwgross]

theoldmoose wrote:
Make sure you don't have the 550EX set on 'master'. It needs to be on the first, or 'single' setting, rather than master or slave. If you read the 550EX manual, someplace in there they explain that setting the 550EX on 'master' automatically sets a flash compensation of -1 stop.


I didn't catch that at first either. It took me three months of staring at images that were about one stop under before I got smarter.

---Bob Gross---

[theoldmoose]

By the way, someone challenged me on another forum to show just where in the manual it says the 550EX goes -1 stop FEC when placed in "master".

I couldn't find it (how embarrassing -- I was repeating something I'd heard elsewhere -- I was just being lazy, seeing as I had the manual right in front of me, and could have checked it out -- my apologies).

It *does* turn out, though, that the 550EX will zoom the flash head out to the 24mm setting if it is set on "master", thus adversely affecting the GN of the flash (that really *is* in the manual :))

In theory, this should affect close-in shots, but certainly can make a difference in high-f/stop and/or distant shots under low ambient light conditions (if you are 'stretching' the GN of the flash, something that would seem to be difficult to do for such a powerful flash, in reasonable indoor situations [low ceiling, etc])

I dunno. All I know is that taking the flash off of "master" seemed to cure my ills. I've yet to do any 'scientific' testing, though, with a target and a tripod, etc. to see if there is really something quantitative about all this.