20D flash never exposes image

[bclyon]

When I take flash pictures with my 20D, the flash triggers to assist in focusing and flashes again when I press the shutter. However, the resulting image is always totally black. This happens no matter what mode I am in. When I first used the camera, the flash worked fine - then it started occasionally showing part of the shutter, then eventually it often had totally dark images, and now there is never any effect from the flash. All of this within the first 200 shots! Has anyone else had this problem, or can anyone advise me of anything I might try (short of either just buying an external flash or sending the camera back to Canon)?

Thanks,

Bruce Lyon

[pierrot]

Check your shutter speed : not set above 1/250s.?

[DaveG]

When I take flash pictures with my 20D, the flash triggers to assist in focusing and flashes again when I press the shutter. However, the resulting image is always totally black. This happens no matter what mode I am in. When I first used the camera, the flash worked fine - then it started occasionally showing part of the shutter, then eventually it often had totally dark images, and now there is never any effect from the flash. All of this within the first 200 shots! Has anyone else had this problem, or can anyone advise me of anything I might try (short of either just buying an external flash or sending the camera back to Canon)?

Thanks,

Bruce Lyon


With the Canon wireless flash system you have all kinds of options and one of them is to have the Master flash-tube turned off. This means that all of the light would come from a slaved flash. But there is still a pulse that comes out of the Master which instructs the Slave to fire, so at a glance it would look like your flash is working but isn't synching with the camera.

So could you have the flash set to Master and then have the Master flash turned off? If you don't have a Slave flash then there wouldn't be any light at all, except for that non-synched instructional pulse. Check the back of the 550 to see if it's set to Master. If it is, flip it back from that setting and check again. If that cures it then that was your problem. Of course you'll have to dig out the instruction book, put the flash back on Master and then work your way through the commands to re-enable the Master flash firing capability.

The other thing that happens sometimes is that the flash isn't seated properly in the hotshoe or more frequently for me it's when the 550 is in the the Off Camera Cord 2. It looks like every thing is OK but the flash isn't quite all the way in. Now this usually results in an over exposure but with a bad connection anything is possible.

[Jim_T]

If things worked normally at first then slowly went south over time, I'd assume there is a problem with the camera.

It sounds like the shutter and flash can't sync correctly. If that's the case, then an external flash should display the same problem.. (Actually, trying an external flash might be a way of confirming the camera is faulty.. If it still won't expose, then it's pretty certain.)

Sounds like the camera has to go back :(

[cruzyn56]

I had an issue with the built in flash on my 2nd 20D (1st one stolen on plane). The metering bars in the viewfinder would all light up then disappear from the outside to the middle, as if the camera couldn't decide on a setting. Having had a previous 20D I thought it odd. I called Canon customer support, and it was determined that there was a problem with it. Sent it back to store for replacement. New one is fine.

[Bob_A]

Even if the flash didn't fire, I would think that you should get a very dark result, not a totally black picture. If it is always totally black, it would be a camera fault ... not a flash fault.

Here's a few questions that may help:

* Does the camera work without flash (maybe the shutter is stuck)?
* What model of flash are you using?
* What shutter speed, AV and ISO are you shooting at?
* Are you using default or second curtain sync?
* Are you waiting for the little lightning bolt in the viewfinder (indicating the capaciter in the flash is charged up) to appear before taking a shot?

Totally black pictures sounds very strange. I've had a few almost black ones in very poor light situations after shooting too quickly after the previous shot ... and I have had a few where there wasn't a hint of image recorded, and the histogram only showed a thin white line on the left hand side, just as if the shutter didn't move.

I'm really interested in what others have to say on this one since last night I had two shots out of about 100 that did the same thing. Prior to last night I took about 1300 images and hadn't notice it.


Bob

[Bob_A]

Did you try powering off the camera and removing the battery for a few seconds? I wonder if the problem may be firmware related, so if the camera is "confused" it may need to be reset.

Bob

[bclyon]

Thanks for your replies.

I should have made it more clear that:

These problems all refer to the built-in flash; I don't have an external flash.

The camera works perfectly in existing light

The "flash" pictures are not always TOTALLY black - but they are always very dark indeed since the shutter speed is not set correctly for existing light conditions when you are using the flash.

Resetting the firmware seemed like a good idea, but no dice.

So it seems like a trip to the shop is inevitable. Sigh.

Thanks for your help.

Bruce Lyon

[Persian-Rice]

Flash compensation settings?

[Monito]

Try experimenting with setting second curtain sync on your 20D (custom functions). Also try some exposures with very long times (2-3 seconds) or with Bulb (open shutter).

As far as resetting, you have to remove both the main battery and the coin sized date memory battery.

[Cadwell]

Shutter sync failing on flash exposures is often an early sign of impending shutter failure. Seems kind of early for a 20D to be doing this, but it's not out of the question. Back to Canon sounds the best bet.