Cotty wrote: > >Can anyone tell me what 'Second Curtain' sync is when referring to flash >gun technology? I've seen it readily advertised with new units - however >not with mf LX/MX and AF280T mutant. > >I realise how the shutter curtains work, how the entire frame has to be
>clear of curtains when the flash actually fires. But what does this >second curtain sync feature actually do for those with that facility? All right... With all electronic flash, the shutter has to be completely open (both curtains clear of the frame) when the flash fires. With standard sync, the flash is triggered as soon as the first curtain is completely open. With second-curtain sync, the flash is triggered just *before* the second curtain begins to close. With flash photography you get an image from the flash exposure superimposed over the image created from ambient lighting. With stationary objects there's virtually no difference between the two and when the ambient lighting is low, the flash exposure represents a very small part of the resultant image. BUT...when you're shooting moving subjects with significant ambient lighting the "ghost" image from the ambient light exposure can often be seen clearly (this is particularly notocible when using long shutter speeds). If you're using standard flash sync, the blurred "ghost" image is made *after* the sharp image. Imagine a shot of someone running; There'd be a sharp image of the runner frozen in place with a ghost image moving forward out of the sharp image. With second curtain sync, the blurred, ambient light image is formed *before* the sharp one, you you'd have a blurred trail *leading up* to the runner. Looks much more natural. -- Mark Roberts www.robertstech.com - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
