Canon Community Canon Community

New Contributor
Posts: 3
Registered: ‎01-14-2014

occasional overexposure with Speedlites

I've seen several threads about exposure issues with speedlites but none that are quite what my issue is.


I have a 580EX and a 600EX-RT.  I use them on a 5D Mk II and a 70D.  Regardless which flash and which body, the same thing occurs.  I shoot in manual exposure with the flash on-camera on ETTL, no compensation. It'll be exposing fine then it will start to over-expose by a stop or two.  I've found that if I turn off both flash and camera then fire them up again the exposures will be correct.  


It doesn't do this often--maybe once in 100 shots, but if that shot was THE shot then it matters!


I'd appreciate any thoughts on this.




Reputable Contributor
Posts: 810
Registered: ‎02-06-2013

Re: occasional overexposure with Speedlites

If it happens only 1 out of 100 and doesn't get worse I wouldn't worry about it.


Apparently there was some problem with the ETTL function...that couldn't properly measure the correct light output required.  Maybe there is some miscommunication between the camera and flash...


or, if you've been using Pocket Wizards, I read that it can potentially causes damages to your flash IGBT circuit which regulates the light intensity of the flash.  Without IGBT, the flash will output at full power, therefore overexpose your images.  

Diverhank's photos on Flickr
New Contributor
Posts: 3
Registered: ‎01-14-2014

Re: occasional overexposure with Speedlites

 If it were just the one shot in 100 it probably wouldn't be such a big deal, but once it starts over exposing it continues to until I do something about it, like turn off the flash and turn it back on again.  So if I don't check the LCD regularly I could  lose a whole sequence. 


 I don't use Pocket Wizards.  

powered by Lithium

LIKE US on Facebook FOLLOW US on Twitter WATCH US on YouTube CONNECT WITH US on Linkedin WATCH US on Vimeo FOLLOW US on Instagram SHOP CANON at the Canon Online Store
© Canon U.S.A., Inc.   |    Terms of Use   |    Privacy Statement