Archived posting to the Leica Users Group, 1998/03/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]- ---COLBYG@ULV.EDU wrote: > It behaves the same way: shutter uncocked, depress shutter release and flash fires... > .. > to determine if any speeds also synchronize? > > >> Is this normal? And, if merely depressing the button (without the > > >>shutter moving) fires the flash, how can the flash "know" exactly when to go With regards to flash going off with the shutter uncocked, it is quite normal and happens to all leica m's. I tested the synch with speeds from 15 to 50 (flash synch) and they do work. Above 50, you will see the picture partly blinded by the shutter screen. The leica m shutter works this way: first, a left shutter screen goes from left to right, thus opening a gap letting the light to the film. The right shutter screen then goes from left to right, thus closing that gap. When the shutter is cocked, the flash synch is triggered by the left shutter screen hitting a contact on the left side. At speed below 1/50 the two screens open a gap as wide as the film width (36mm), thus you have complete lighting on the exposed area. At higher speed, the opening gap is smaller than the 36mm of the exposed film area, thus you get partially lit film. This gap travels the whole range of the exposed area so you have complete exposure with constant light. Flash light is about 1/5000 sec, so only a portion of exposed area get light at shutter speed higher than max synch speed. This is hard to explain without a diagram, hope you get it. Anyway, synch works for all speed below 1/50. _________________________________________________________ DO YOU YAHOO!? Get your free @yahoo.com address at http://mail.yahoo.com