Canon on camera flash overexposed

[kevs]

Before I call Canon: Has anyone experienced with their on camera flash?  The subject are wildly overexposed with TTL?

Usually ok, but recently getting this.. both 580 and 430.. Canon 5D 2

[tcphoto1]

You might want to check the +/- settings on both body and flashes. I find that using a Canon speed light indoors with bright background will produce 1-2 stops overexposed images and needs to be manually adjusted.

[kevs]

thanks TC I don't think it'd those 2 things but will examine again for sure.

[JaapD]

Can you tell us more about the conditions? Only at short distances, at high ISO settings?

Reason for asking this is that each flash has a certain working range, for instance a flash duration between 1/500 and 1/20.000 sec. In case you shoot at a short distance and at high ISO the required flash could even be shorter than 1/20.000 sec. The TTL flash will fire at 1/20.000 sec resulting in overexposure.

Regards,
Jaap.

[kevs]

Only at short distances, at high ISO settings?

Thanks Jaap. I have not thought about that...   This may be the case... so  I should test on subjects at short and long and low iso and high iso?

I did not understand the tech stuff after that, but I'm sure its valid..

[JaapD]

Just check let’s say at native ISO (100-200), in the house, an object between 2-4 meters (6-12 feet) away, not completely black or white. If you’ll get a properly TTL exposed image now, then my conclusion would be that both flashes are just fine.

Not mentioned before: are the contacts between the flash and the camera clean?

Regards,
Jaap.

[kevs]

Thanks Japp, will do this test great.  I have never cleaned contact so I assume fine.. but time, what you use to clean?

[JaapD]

Hi Kevs, regarding cleaning contacts …. nothing special …. a dry microfiber cloth would do just fine I think.

Regards,
Jaap.

[mshea]

I had the same problem with that camera and  flash combo. The flash would spontaneously change from ETTL to TTL, resulting in dramatically overexposed images. As the years went by it seemed to happen more often in the portrait position. Cleaning the contacts didn’t seem to help much.  My sense was that the fastener on the flash just became looser over time.