Speedlite 430EX II & Speedlite 600EX-RT underexposed.

[rrnkp]

Hi,   I have 430 EXII and a 600 EX. On my t6i both flashes set to E TTL  work properly in all modes  auto, program and manual, with the exception of the exposure confirmation lite on the 600 EX. It does not illuminate.

Now the weird part when I use either flash,E TtTL, on the the 70d both flash are under exposing but the exposure confirmation light flashes on the 600 EX, meaning it was properly exposed. Either I have to go +3 on exposure compensation or manual 1/1 for the pics to come out properly. This occurs in all modes auto, program and manual.

I'm photographing dimly lit parking lots/ streets at all distances. Both cameras have 18-135 Canon lens. 
I’ve tried the Canon 18-55 and 50mm f1.8 on the 70d still under exposed.  
 Any ideas on what’s going on?

[deebatman316]

1. The OP is describing different problems. So we need to let them describe the problems separately for both cameras. There are different variables too. They could be using off camera flash. Off camera flash FEC works differently. Then one on camera speedlite does. FEC can be dialed in on the speedlite or in camera. Optical wireless must be done on the speedlite itself. Radio wireless is done in the camera or on the sender speedlite.
2. No I was not criticizing you. I was only pointing out what the speedlite manual says. I also tried setting FEC on the speedlite and the camera at the same time. The speedlite's FEC took effect and the camera's was ignored. Unless the speedlite's FEC was set to "0". Then the camera's would be applied.

[Anonymous]

From what the OP states, it seems it is either a setting on the 70D or a bad hot shoe connection on the 70D, since both flashes seem to work on the T6i (give good exposure).

[deebatman316]

I was thinking the same thing too. Some 430EX II (& 580EX II) speedlites had to have the hot shoe foot redesigned to have "pointy" contacts instead of "round". This didn't affect the 600EX series of speedlites. Usually but not always when those speedlites aren't communicating properly with the camera. The speedlite reverts to Off The Film TTL and will always fire at full output. Since Off The Film TTL is Incompatible with digital cameras. Also the in camera flash menu won't work either. The camera will report "Speedlite's power is turned off, Incompatible Speedlite attached". This is true for some of Canon's speedlites because NOT all of them support the in camera flash menu. Only speedlites released from 2007- present support it. Or it could be a setting problem too. But CF are disable in Full Automatic an other Basic Zone modes.

[rrnkp]

Thanks for all the responses.

The 600 ex rt is the correct model, sorry for the confusion.

When photographing I am standing in the same spot, shooting the same scene.

fec is set to zero on both cameras. I even tried changing the lettering on 70d no help.

both flashes fire on the 70d but very low power.

I am using the t6i with the 430 ex ii alone no other flash. The 600 ex rt is not powered on. I power off the 430 remove it and put the 600 on the t6i works as it should. Turn thr flash and t6i off.

Grap the 70d put the 430 on, the 600 is off.   Under exposed pic.   Remove the 430, it’s off.  Put the 600 on same thing.    I either have to go manual or +3 on flash.

[rrnkp]

Further.  I am using the hit shoe on both cameras.   

[deebatman316]

Are you using off camera flash. Or just 1 speedlite in the hot shoe. What happens when the 70D is used in Full Auto. Is the picture still underexposed. Please post pictures in the forum.

[Anonymous]

The only thing else that comes to mind, is to reset the camera to factory defaults.

[deebatman316]

Or they could try live view. Live view uses a completely different metering system then live view. It sounds like the "weak" flash is possibly the E-TTL pre-flash. Which is 1/32nd power level I believe.

[rrnkp]

I have rest the 70d twice.    I have not tried live view.    Thanks for the tip.

[deebatman316]

It sounds like your only seeing the E-TTL pre-flash. Your camera is NOT firing the main flash. E-TTL consists of 2 flashes but it looks like 1. You have the pre-flash then the main flash. The pre-flash is fired before the shutter is open. The camera uses the pre-flash to calculate the correct flash power.