Archived posting to the Leica Users Group, 2001/12/12
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]"The TTL uses a electronic flash sync and will not fire the flash if the shutter speed dial is set above 1/50. John Collier" I think the questioner deserves an explanation of why this is. The focal plane shutter sets up a slit of varying widths. For speeds of 1/50 and below, the width of the slit is the length of the 35 mm frame. For speeds below 1/50, the curtain pauses with the open slit in position for the required length of time. For speeds of 1/50 and above, the slit travels across the film at a fixed speed. The way higher shutter speeds are obtained is by making the slit narrower. So, when set, for example, to 1/250, each spot on the film is exposed for 1/250 second, but the total time the slit spends travelling across the film is still 1/50 of a second. Hence, if the flash were permitted to fire, only a narrow band of your negative would get exposed. Herb - -- Herbert Kanner kanner@acm.org 650-326-8204 - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html