Paul C. Buff, Inc. Technical Forum

Doing a room on location that required a pop of all the units and long exposure I needed ten seconds on one set-up. The Einsteins fired a second time sometime around the 8-second mark. Never happens on shorter shutter times. It happened every time I did the long exposure.

I had three heads, I think, and the trigger was a CST in the shoe. I have a Cyber Commander and assume it was "asleep" at the time. Canon 5DMk3.

jonathan7007

This is an issue in the CST firmware when using long shutter speeds, but it does not happen with every camera. A correction will be implemented in future CSTs.

Cyber Commander does not exhibit this behavior.

How long an exposure speed will cause the second pop? Any guidance?
Is this behavior exhibited will all units of any one model (all 5Dmk3, all 1Dsmk3) or varying among individual camera bodies?

Makes the CST way less helpful for the architectural/interior images I am asked to shoot. Is the change now made for new CSTs?

I do appreciate the straight answer.

jonathan7007

It is once every 9 seconds. I believe it was a Fuji camera that did not experience this, and there is only the one case that it did not happen.

The change in programming is complete, however,we do not have any production units yet.

You can't change the firmware on the CST, right? I have to buy a new one?

9 seconds isn't too bad, and I guess I'd try to avoid that solution to ambient exposure. Luckily the newer sensors are so forgiving at higher ISOs.

jonathan7007

The firmware is not upgradable. A different CST would be necessary.

Alternatively, you could trigger the lights manually, or load the CC into the hotshoe.

Knew I could use the CC as trigger. Mine seems a little flakey as a shoe-trigger, so I was glad the set I got had the CST to do dedicated duty as the firing trigger. I'll work around the limitation.

Thanks for the info on firmware. Please make a announcement when "CST The Sequel" is released to a theater near me.

jonathan7007