Peter Klein
Well-known
Sorta OT, but there's a lot of expertise here, so here goes:
Is there some issue with generic "auto-thyristor" flashes and digital cameras that would lead to inconsistent exposure? Somebody told me that when you combine auto-thyristor electronic flash with a digital sensor, the digital sensor may not "see" what the thyristor does. Anyone know more about this?
I was about to go shoot candids at a friend's wedding, using my Leica and B&W film. I knew I could use available light until night fell, but would have to rely on flash afterwards as the venue was very dim.
Being a usually faithful devotee of available light, I hadn't used my Vivitar 2500 in a while. So I put it on my Olympus E-1 DSLR for a quick test. The flash shots were overexposed close up and underexposed *drastically* at medium to far distances supposedly within its auto ranges. Almost as if the sensor was only paritally working. I got the same general results with direct flash, bounce flash, and a Lumiquest "Pocket Bouncer."
Then I got suspicious. I tested again, this time with another flash (direct only). I got similar results. (Yes, the flashes' trigger voltages were within the E-1's tolerances, and I was shooting below the camera's maximum shutter speed for flash).
Based on all this, and the fact that both flashes worked last summer, I decided that the problem was not with the flashes. I went and shot the wedding with my M6 and the Vivitar 2500. It worked fine, with both bounce flash and the occasional direct shot. There was a little variation from near to far, but well within film latitude.
Here's a picture from the party after the wedding, using bounce flash:
http://users.2alpha.com/~pklein/currentpics/MadHotBallroom.htm
--Peter
Is there some issue with generic "auto-thyristor" flashes and digital cameras that would lead to inconsistent exposure? Somebody told me that when you combine auto-thyristor electronic flash with a digital sensor, the digital sensor may not "see" what the thyristor does. Anyone know more about this?
I was about to go shoot candids at a friend's wedding, using my Leica and B&W film. I knew I could use available light until night fell, but would have to rely on flash afterwards as the venue was very dim.
Being a usually faithful devotee of available light, I hadn't used my Vivitar 2500 in a while. So I put it on my Olympus E-1 DSLR for a quick test. The flash shots were overexposed close up and underexposed *drastically* at medium to far distances supposedly within its auto ranges. Almost as if the sensor was only paritally working. I got the same general results with direct flash, bounce flash, and a Lumiquest "Pocket Bouncer."
Then I got suspicious. I tested again, this time with another flash (direct only). I got similar results. (Yes, the flashes' trigger voltages were within the E-1's tolerances, and I was shooting below the camera's maximum shutter speed for flash).
Based on all this, and the fact that both flashes worked last summer, I decided that the problem was not with the flashes. I went and shot the wedding with my M6 and the Vivitar 2500. It worked fine, with both bounce flash and the occasional direct shot. There was a little variation from near to far, but well within film latitude.
Here's a picture from the party after the wedding, using bounce flash:
http://users.2alpha.com/~pklein/currentpics/MadHotBallroom.htm
--Peter