I have a question about the flash sync on the phaseone df with ls lenses.
I was at large equipment rental today ordering lights for an upcoming shoot next week where I need hi speed flash sync.
It was suggested to me to use the Broncolor Grafit 4's because with them you can dial in the flash output and the generator will show the specific flash duration at that power setting.
In this manner you can actiually see that you're output is within the sync duration of the shutter speed and so find the peak power output that the Grafit 4 can give you at your highest sync speed.
Well, I've been mislead too many times to leave it to chance, so I had them set up the lights that I will be using to test the setup.
I tried three different ls lenses on two different 65+ backs and two bodies with air sync transmitters and hard wired.
In every scenerio I would get the full flash output at shutter speeds of 1/125th of a second. Above that shutter speed the power would decrease exponentially.
At 1/1600th I was getteing about 4 stops less light.
This doesn't make sense to me because by using the output level of the Bron power pack that gives me a flash duration of 1/1600th I should not be cutting the power of the fash by moving from 1/125 to 1/250th...
Nobody at the rent studio could explain the problem.
I think I have an idea what it could be, but maybe someone here could confirm or correct my assumtion.
I suspect that the firmware of the back or the body isn't up to date.
I think the back was 1.2.1, I'm not sure though, because I didn't have a manual to find out how to check the firmware.
Anyway, if anyone knows what the problem might be I'd appreciate the help.
I was at large equipment rental today ordering lights for an upcoming shoot next week where I need hi speed flash sync.
It was suggested to me to use the Broncolor Grafit 4's because with them you can dial in the flash output and the generator will show the specific flash duration at that power setting.
In this manner you can actiually see that you're output is within the sync duration of the shutter speed and so find the peak power output that the Grafit 4 can give you at your highest sync speed.
Well, I've been mislead too many times to leave it to chance, so I had them set up the lights that I will be using to test the setup.
I tried three different ls lenses on two different 65+ backs and two bodies with air sync transmitters and hard wired.
In every scenerio I would get the full flash output at shutter speeds of 1/125th of a second. Above that shutter speed the power would decrease exponentially.
At 1/1600th I was getteing about 4 stops less light.
This doesn't make sense to me because by using the output level of the Bron power pack that gives me a flash duration of 1/1600th I should not be cutting the power of the fash by moving from 1/125 to 1/250th...
Nobody at the rent studio could explain the problem.
I think I have an idea what it could be, but maybe someone here could confirm or correct my assumtion.
I suspect that the firmware of the back or the body isn't up to date.
I think the back was 1.2.1, I'm not sure though, because I didn't have a manual to find out how to check the firmware.
Anyway, if anyone knows what the problem might be I'd appreciate the help.