schristie11 Offline Upload & Sell: Off
|
Last I checked, people are not moving at 30,000 rpm, but regardless 1/500 is not hard for a flash to keep illuminated for full shutter travel, by strobing continuously.
So when using a Flash with HS on a person runing 1/500 or 1/2000 will work great and still get plenty of light from the flash within the shutter time.
I have even used it at 1/3000 successfully in some situations.
Want to know how? Then read on:
"In high speed sync mode, the flash fires continuously, many thousands of times per second. All these pulses of light essentially merge together into one long "pulse" that stays on the entire time the shutter is open. This is a lot of work for the flash to do; but it only has to do it for very short periods of time (i.e., less than the standard sync speed, such as 1/200 sec or less).
So in high speed sync mode, the flash stays "on" for the entire time that the shutter is traveling across the frame. There's no longer a problem with parts of the frame blacking out behind the shutter curtains as they sweep across the frame. Now you can use fill flash at shutter speeds of 1/8000 second! "
"At speeds above the maximum sync, the curtains can't move fast enough to fully open and then quickly close. So camera designers employ a neat trick:
At high shutter speeds, the second curtain begins to close before the first curtain fully opens. In this way, a band or slit of exposure moves across the frame, which effectively yields a short shutter speed."
-http://www.rpphoto.com/howto/view.asp?articleID=1026
Oh and for those that dont know:
"Nikon has done the world a great favor in the D1, D1X, D1H and D70 cameras by adding an electronic shutter to take care of the faster speeds. By doing this the sync speed becomes unlimited."
http://www.kenrockwell.com/tech/syncspeed.htm
Nikon has added more intelligence to the HS method with FP mode.
http://imaging.nikon.com/products/imaging/technology/speedlight/function/fp.htm
Edited on Jun 12, 2010 at 07:17 PM · View previous versions
|