Within the last few weeks, my trusty Canon 580 has become somewhat unreliable. Sometimes it gives me full power; other times it does not (even after ample time for recharging). When it does this, the flash fires, but the image is underexposed. I do use rechargeable batteries (Duracell 2650 mAh). I have heard that they may cause a problem, but I also have a Quantum Turbo Battery hooked to it. Has anyone experienced this? Is it time to send the flash in to Canon? Any help would be appreciated. Thanks!

oh yes...I have been meaning to start a thread on this myself!....so glad YOU did.

I had a Sigma equivalent flash that was doing that to me quite a bit. I was mystified, and eventually decided to solve all my flash problems and buy the Canon 580ex. Guess what....first wedding I used the 580 I was having exactly the same problem...not all the time, only sometimes. I am now fairly sure it's user error. I think maybe I'm 'missing' something. I MUST be....cause the chances of both those flashes having the same fault is remote.

If you don't mind Shan...I could post some horrible examples, complete with the exif data.....

Annie

were you shooting in ettl or M?

ettl is awful, and its irregularity could easily explain the random underexposure

Gee whiz! And this whole time I thought it was me Actually, maybe it still is me. hmmm... I've been having problems with my flash underexposing too. It's almost like the flash doens't even go off, but I know it does cause I watch for it! Darn machines.

ETTL - but it never used to do this. It is a recent problem.

One thing you might do is scan the pictures you took and look for things like reflective surfaces. That can cause the flash to cut way back and underexpose badly. Have you tested the flash in manual mode to see if it's firing properly everytime? If it does in manual it should in ETTL too.

I thought it was due to reflective surfaces as well. Of course, that happens sometimes, but I don't believe that is the problem. It is happening too frequently. I will test it in manual today. Thanks!

my EX is failing me too! canon flash is expensive and it sucks. sorry, no help here... just ranting.

//ed

If this is typical of Canon flashes, what flash would everyone recommend?

its more the ettl, the actual flash works great

metz are great, unless you have to change the settings in a hurry

Wow....I didn't know that! When I went back through the worst of my duds I found one thing in common. MIRRORS!!!!!

Now I know, I guess the trick is to switch to manual when there's a mirror in shot. I REALLY learned something major from this thread!!!


Annie

You may need to replace your rechargeable batteries with a new set. Mine was doing it too and seemed to get much better with the new ones.

With ETTL, TTL and Auto settings not only reflective surfaces, but also a lot of light colored surfaces will cause underexposure. A beautiful bride in a pretty white dress is a perfect example. More light is bounced back to the sensor causing an underexposed image.

Ohhhh... so every time I'm shooting a wedding and there's a BRIDE in my shot, I should switch over to manual?

Phew....so glad I paid all that money for the ETTL flash!
(sarcasm, the lowest form of humour)

Seriously, this is so great to be made aware of ETTL's limitations. I have been BAFFLED with some of my results lately. They should put a BIG disclaimer about this on the box...ha ha ha ha

Annie

it's fixed in the 'new' version Annie.










ok I'm kidding of course - I don't know. I used ETTL once, I took 2 shots, just seconds apart of my son at the beach on a dull day, didn't change the settings, didn't move the focus point just bam bam - the first one was like there was no flash, the second like I nuked the poor kid.

needless to say I used M ever since - and have had no issues at all (except for user error )

Anne,

ETTL isn't a bad thing you just have to know how it will react in these situations. I have learned to keep an eye on my histogram in these situations and make manual adjustments to the output by using the +/- adjustment on the back of the flash.

It takes a bit of getting used to. If you have the time and a good meter, manual works.