Canon screws with flash speeds

[Jonathan Wienke]

It's doubtful changing to Nikon would help; the problem is most likely your wireless trigger. I've shot with strobes outside at 1/250 on several occasions, and never had any problems syncing. Here's some samples; check the metadata for particulars, but all involve strobes outside at 1/250.

[attachment=13675:2005_06_12_0070w.jpg] [attachment=13676:2005_07_02_0052w.jpg]

The band portrait was shot with the 1Ds, the car show with the 1D-II.

[janisr]

noo, not switching to anything - other than this, I ejoy canon, just wanted to know - is it really the transmitter, because, even using the cable, the problem still is there

[wollom]

This is no flash falloff,
here is a test shot with a broncolor ringflash - no falloff here - if I do a test shot, it looks even worse:
shot at 1/250 - which is supposed to be the top sync speed, the first usable with studio strobes is 1/125
with canon speedlites there are no problems - works fine with the high speed sync mode enabled.

I use Bron with Pocket Wizards and can sync to 1/200th with a 1Ds.  

Looking at your samples, the vignette/light fall off looks very gentle; not what I'd expect where a high shutter speed means the flash is catching the second shutter curtain partly covering the sensor.  Your test  images look more like the syncing is too late or too early. In this case I think it's triggering too late. I think the shutter in a Canon 1D travels down the camera; that is up the image. In your test we are seeing what looks like the rapid rise in brightness of a flash that is being triggered too late. I even guess that it's being triggered about 1/500th (0.002 sec) of a second too late.  Does the RFS system/pack you are using have some facility (like the Graphits) to delay triggering?  Have you got that turned on?

Just a thought.

Wollom