With gravity operated shutter the two blinds are accelerating so the effect of the gap is non linear. For an given increment of time the space has to increase by more than for a constant speed shutter blind. I'll sit down and try to calculate it if you wish. Quoting TERRYAKING@xxxxxxx: > So far as I understand it he variation of the 'speed' of a focal plane > shutter is obtained by varying the width of the slot in the blind of a > shutter > which, in fact, moves at a constant speed. It has been suggested that > varying > the width a slot in a gravity actuated shutter in front of the lens would > not > have the same effect of varying the speed. If this is so, why would the > effect > vary between the two types of shutter ? > > Terry > > Terry King FRPS > > RPS Historical Group (Chairman) > > _www.hands-on-pictures.com/_ (http://www.hands-on-pictures.com/) > > Moderated Discussion Group > > Post message: artaltphot@xxxxxxxxxxxxxxxxx > > Subscribe: artaltphot-subscribe@xxxxxxxxxxxxxxxxx > Unsubscribe: artaltphot-unsubscribe@xxxxxxxxxxxxxxxxx > > 1. An excellent thing is as rare as it is difficult.(Spinoza) > 2. A man's reach should be beyond his grasp or what's a heaven > for.(Browning) > 3. Frustra fit per plura quod potest fieri per pauciora.(Occam's razor or > 'Keep it simple!'). > 4. Nullius in Verba (Horace), 'Take no man's word for it' (motto of the > Royal Society). > 5. If ignorance is bliss, why are not more people happy ? (anon) > ---------------------------------------------- This mail sent through http://www.ukonline.net
