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If I set my camera faster than 1/200 second exposure time, it doesn't work with flash illumination. I've seen this on other cameras, so I assume that it's the way it is with a standard flash.
I've had similar problems with florescent lighting.
Are there setups can can go faster, say 1/1000 or so?
I'm guessing that there's no way to make that happen with my cactus/vivtar setup, but if somebody knows, please share!
My Canon Speedlite 430 EX (older model) has High Speed Sync on it. You can select it and it can sync at faster speeds. I am not sure if Cactus/Vivitar models can do this as well to be honest: check their manuals?
Depending on the camera you have to go into the CF and change the flash settings to Auto and not fixed 1/200 then the flash has to be able to go to high speed sync. As mentioned above the Canon flashes will do this. Don't know about your setup though.
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Originally Posted by Colin
Remote triggers might struggle if not miss completely at high flash speeds. Probably not much you can do.
With fluorescent lighting, you're better at shutter speeds of 1/60th or slower, so you're catching an entire wave. 1/120th might work OK as it'd be half of a wave.
The new Pocket Wizard Mini/Flex units can push "normal flash" shutter speeds significantly faster than a particular camera's sync speed, but at best you're probably looking at 1/500th. High speed sync on a flash is another way to push shutter speeds faster, at the expense of light output from your flash.
You don't say which flash and camera you have. That will be very important. Read your flash manual about high-speed sync. The problem is that, at shutter speeds over 1/200, the shutter on a DSLR is never completely open. The shutter is really two curtains that travel vertically (the short dimension of the frame). Before the shutter release is pressed, the first curtain is closed and the second curtain is open. When the release is pressed, the first curtain starts down (or up?) across the frame. The second curtain follows after the selected shutter speed. At speeds above 1/200, the second curtain starts across BEFORE the first curtain has completed the course. In essence, a strip of the image is being exposed. When the flash fires, it will expose only a strip. Some flashes can get around this by firing the flash many times, very rapidly, as the two curtains trave across the sensor.
I can help if you have a Canon 580EX or a Sigma 500 series flash.
Thanks everybody for the education. the curtain explanation makes everything more sensible. I was wondering how the bottom of the picture was the part getting cut out...
The cameras are a 5d and 30d. the transmitters are cactus v2's, and the flashes are vivitar 285HV. I'll crack the manual.
.....
I can't see anything in the manual about a high speed sync.
I did find something in the custom function menu about 1st or 2nd shutter sync. Any idea about what that is?
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Originally Posted by Colin
That's the sort of information that would have helped a lot.
The Vivitar flashes can't do high-speed sync. Only ETTL-compatible flashes can. You're stuck with using 1/200 or slower. Slightly slower would be better because of the delay in triggering the flash with the remotes. I'd suggest 1/90 or 1/60 to be certain.
First curtain sync means that the flash fires just after the first curtain opens. Second curtain sync means that it fires just before the second curtain closes. The usual situation where that is important shooting a fairly fast-moving object with a fairly slow shutter speed in enough light where there will be at least a partial image from available light. The classic example is a moving car. (Despite my predilection for equine transport, I'll use the car.) If you use first curtain flash and a fairly slow shutter speed, you'll see a "clear" image of the car with streaks going in FRONT of the car. The streaks are from the available light. That's a very odd-looking photo. If you use second-curtain flash, the streaks will be BEHIND the car, as the available light image will be exposed first, then the flash fires. That will look more natural.
You've just given me an idea for some shots at a horse show, though I'll have to clear using flash with the riders.
Thanks for the info.
I look forward to seeing your horse tracers [:)]