Pentax K-1, Pentax AF540FGZ II, Cactus V6 II - Reduced flash output in M mode

Chernobog

Hi, everyone,
I've just joined this community, I am a Cactus user since last August.

I'm asking for your help to solve a problem with the following equipment:

Pentax K-1
Pentax AF540FGZ II
2 x Cactus V6 II

The flash output reaches the full power in TTL mode, but in M mode at power 1/1 the output doesn't reach its GN54, it's about 1EV less.
To use M mode I leave P-TTL on the flash body.

If I set M mode both on the flash body and on the V6 II the output reaches the GN54, but it shoots only at full power, the setting 1/2 ÷ 1/256 doesn't affect the output.

I've made my tests to be sure, even exchanging the triggers TX-RX, I've updated the firmare to the latest version V3.07.

Can you kindly find a solution?

Chernobog

Finally I've found how to restore the normal functioning thanks to this forum, it was enough to do a Factory Reset. Surprisingly the triggers have kept the firmware PEN.A.005.
Thank you anyways.

Chernobog

The problem takes place again, and this time Factory Reset doesn't help.

I have tested my system.
I set P-TTL mode on flash body and M mode on V6 II.
At zoom 24 mm the flash works properly, at zoom 28 the output is reduced by -1/3 EV, it decreases gradually until -1 EV at zoom 80 mm.
In TTL mode all works properly.

Chernobog

Another limit that I found is that V6 II doesn't trigger in live view mode.

Class A

@raychan

Hi Raychan,

poor Chernobog does not appear to make it through to Cactus support.

The described behaviour could be due to some weird P-TTL flash logic, but it could also be due to a bug.

@Chernobog

Have you tried the multi-brand version (e.g., V1.1.019)?
If you don't need P-TTL, the multi-brand version may work better for you. Might be worth a trz, even just for troubleshooting to see whether you'll observe the same loss of power when using manual power control.

raychan

@Class A This could be a bug. Let me check with our engineer for further assistance.

Chernobog

@Class A

I haven't tried a multi-brand version, I rely upon manual mode, but I may need P-TTL mode with mixed lighting. For the everyday use I can by-pass this bug because I don't set the zoom to 85 mm, I usually set zoom to 24 mm, in order to cover the angle of a softbox or an umbrella.