EOS R7 locks up, chooses wrong exposure with Godox TT350c

[ajm133]

I seem to be struggling with using my r7 with Godox TT350c

     Using the camera In full auto mode (TTL on the flash, A+ on the camera)

     In very dim light- as in almost dark – there will be a brief pre-flash and then the camera locks up with an error E-70.  Need to turn off camera and sometimes take out battery to get it back to normal.  I know this is not a typical way to shoot but I tried it because I know my t3i would just focus as best it could then take a shot

     In low light, the camera will choose a very slow shutter speed and take a shot. I don’t see a pre-flash. My former t3i with Yongnuo flash would handle it with no issue and typically take a nice shot.

     The flash firmware is 1.7 which appears to be the latest version, and camera just pgarded to 1.4 (1.3.1 acted the same way)

     When shooting in Av and M mode it seems to act the same – essentially if there is not a lot of light the camera locks up.

[deebatman316 · Accepted solution]

Godox speedlites are incompatible with Canon's R series mirrorless cameras. Godox will have to resolve the problem with your speedlite. Canon can only grantee compatibility with their products NOT 3rd Party items. "In very dim light- as in almost dark – there will be a brief pre-flash and then the camera locks up with an error E-70." It appears that the camera is trying to use the speedlite for AF Assist. The "brief pre-flash" sounds like an AF Assist Beam. The red/ IR grid pattern projected by speedlites IS NOT COMPATIBLE with mirrorless cameras. When a Canon EX or EL speedlite is used on the EOS R series. A Canon speedlite will switch to Intermittent Flash Firing (IFF). Even if the speedlite has a choice between IR & Intermittent Flash Firing the setting is automatically overrided to Intermittent Flash Firing. 3rd Party speedlites DO NOT to understand the modified AF Assist Beam signal from the camera. Thus causing the camera to lock up or the IR grid pattern to be emitted when its not supposed to. Note depending on the AMBIENT LIGHTING an LED AF Assist Beam may be projected by the camera body instead of the speedlite switching to Intermittent Flash Firing (IFF). 

[deebatman316]

Then the EL-100 fits your needs as you said that you use it in low light only. Since the EL-100 lacks on speedlite controls. I would recommend that you learn how to use the camera's in camera flash menu. Note in order to use the in camera flash menu. A Canon speedlite that supports it must powered up and in the hot shoe. All changes to settings must be done through the in camera flash menu. Setting flash sync will also be done in camera such as High Speed Sync (HSS / FP), 1st curtain / normal sync & Rear curtain/ 2nd curtain sync. The E-TTL metering pre-flash is visible with rear curtain sync which is normal. Rear curtain sync is used with long shutter speeds and it can only be used with shutter speeds slower than 1/30th on most cameras. So check your camera manual to see what shutter speeds it can be used with. The same applies to High Speed Sync (HSS/ FP) every came has a max sync speed. Most cameras are 1/200th or 1/250th but this varies between camera models. A more powerful flash would be needed for High Speed Sync (HSS/ FP). The speedlite would be discharged after a few shots since High Speed Sync (HSS/ FP) requires the flash to fire multiple times (pulse) during the exposure.