Can anyone explain his issues with the sync speed at 1/200 with the markii/iii?
I'm confused by that. I know that this is an expected result from cheap china triggers. But with PW also? I don't get any of that on my mark II when using the canon optical system. And even my cheap triggers work at 1/200 most of the time
Any thoughts why this is?
It has a lot to do with the transmission lag from the remotes to the camera and flashes and, more importantly, the speed at which the Canon shutter closes to capture the light. Too fast and the shutter closes before all the light from the flash "registers" in the image. First party flashes (like the Canon 430EXII or 600EX-RT) are built to work specifically with their brand bodies.
Pocket Wizard developed something called "Hypersync" that offsets the flash trigger to try and account for this, it works better with some cameras than others, but I've been able to get an extra stop (at least) out of my 5D3 using this. As always, mileage varies.
Hm. I see what you're saying but there is still something here I don't get.
Let's leave out the "Hypersync" versions of the PWs. That would be basically their version of HSS with ETTL. I think that doesn't apply for their "dumb" triggers such as the Plus III and X.
So if those are rated for up to 1/250 and the MarkII and III can go to 1/200, why would there be an issue at that speed? The flash pop will be much much faster than that during that time and should illuminate the entire frame. If that's not the case then I can only think of two explanations (neither of which should happen really):
1. The cameras are rated at the max sync speed of 1/200 which (if I understand it right) is the fastest speed where the shutter curtains are at one point NOT covering the sensor. Every speed faster than that will be a smaller slit sliding across the frame and result in dark bands when the short flash pop occurs during that pass through. So this would mean that the cameras really don't have that sync speed and that the curtains are ever so slightly closed at that speed already. This seems unlikely since it clearly works with the Canon system at that speed.
2. A mismatch or delay in trigger time of the actual trigger. That would mean the PWs reach the flash delayed and they only pop after the curtains are already closing again. Or maybe the reverse where it's too early because of some shutter delay. Don't remember which direction the horizontal shutters move. The dark bar seems to be at the bottom. I've seen the same thing happening on my $25 China triggers at times. Not consistently though.
Why make a big deal? I think it matters. 1/200 is pretty slow already if you like shooting with wider apertures while trying to control ambient light. I know, that's what HSS and Hypersync is for. And that's why I'm still on the fence about all this. No good solution is cheap. None is 100% flexible. Or 100% reliable it seems.
I think my next investment is really going to be a medium format film camera for that kind of stuff. Leaf shutters and all. Anyone seen the Gregory Heisler book? Delicious. That's the kind of stuff I want to do more.