Canon EOS 5D IV compatibility problem

weigertj

Hello,

yesterday I tried the original Cactus V6 (I) on the Canon 5D MK IV at a wedding. When I switched to TTL mode, it overpowered the flash and everything became overexposed (the image looked almost white, like using full power). The Canon 5D MK IV also has compatibility issues with Cactus V6 II (please, see my other thread). The same Cactus V6 works flawlessly with the Canon 5D MK III, I used them side by side.

weigertj

I forgot to say, the flash was on top of the Cactus V6 (TTL passthrough).

Antonio

Thanks @weigertj for reporting the issue.

I will pass the information to our R&D team to investigate.

Cheers.

EDIT:  Are you running firmware version 2.1.001 on your V6 MK1?

weigertj

Thank you, Antonio.

Yes, I use the newest V2.1.001 firmware.

Antonio

Thanks for the confirmation. I have advised R&D.

weigertj

Thank you.

I tried to repeat the problem but I couldn't, it worked fine right now in my room. AF assist light signal is passed to the 430 EX, it works fine.
However, I had overexposed images at the wedding with TTL passthrough.

weigertj

I am not sure anymore, that I had a problem with the Cactus V1, too. I can repeat now the overexposed TTL images with both the Canon 5D4 and 5D3 + Cactus V6 II!
Sorry, I just had too many variables and it is hard to remember exactly.

Antonio

Thanks for the extra info. Seems like there's a bug on TTL pass through on the Canon system.  We will try and fix it ASAP.

weigertj

Thank you! If I have more test result,s I'll let you know.

Antonio

We could not replicate the same problem on our 5D4.

The TX unit only behaves weirdly (constant flashing of Status LED in green) when we manually select the on-camera flash as "MANUAL".

Have you selected Canon flash on the V6 TX before switching on TTL Pass Through?

Thanks!

weigertj

Hello Antonio,

I couldn't replicate the problem anymore, either. There is a chance that I didn't remembered well and I had problems only with the V6 II.

Antonio

Ah okay, no worries.

Just let us know if the problem is back. Cheers!