x-sync question

What happens when you shoot at a faster speed than your camera syncs

at, Say 1/250, when you camera syncs at 1/200. Would it freeze the

action better, but mess up the exposure?

If it's a new camera, it will probably enter FP-Mode (fast sync mode) where the camera fires a bunch of short bursts of flash. It works, but you're apparent flash power is reduced.

 

Older cameras will either not let you shoot at that speed (reset it to the X-Sync speed) or will let you shoot and you will only get a partially exposed frame.

 

Read your manual.

...if the primary light for exposure comes from the flash, it will not freeze the action better. On the contrary, it may even make it look more blurred because instead of one quick flash of 1/1000th sec, it's several flashes spread out over 1/250th sec. I can't say for sure, though, since I've never tried to freeze action in FP-Mode.

yeah, its a canon a2. dont think that has FP mode or w.e, and i know that it allows you to shoot 1/250 even though that isnt what the sync is.

The limit of the sync speed is a function of how the shutter works. In order to get a (focal plane) shutter (disregard flash duration for the moment) to open and close very quickly, it is not simply a matter of putting a curtain that lifts out of the way and back again in, say, 1/500th of a sec. To get the high shutter speeds, the shutter uses two curtains. One starts moving from the left thus opening progressively the film frame to light. Before it reaches to opposite side, a second curtain starts following it across, closing that "gap". This way, any one area of the film has effectively been exposed for 1/500th of a sec, although not at the same 1/500th. Imagine a band of opening sweeping across the film frame. <p>

Now, as your flash duration is only say, 1/10000th of a second, if the entire film frame isn't exposed at one given ten thousandth of a second, then you will expose to the flash only one portion of the film. If you try faster shutter speeds, you will actually see the shutter curtain blocking part of the frame.<p>

Harder in words... was that helpful?

That was quite helpfull. Im not with you 100 percent, but I get the point.