Archived posting to the Leica Users Group, 2003/02/23
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Howdy Before Quartz control, all "electronic" shutters were controlled via capacitive discharge. The cap acted as a delay circuit discharge time was controled by modifying the discharge network either through trhe introduction of new RCL elements or by varying source voltage to the network. IE putting a resistor in shunt with the cap would make it discharge more quickly. Interestingly enough the primordial electronic shutter is not truly electronic since there is no amplification going on. Similarly the digitally driven cameras are notb truly digital in that that there is no inferencing, interpolation or the like going on except for low level counters and bar segments. BTW: the old ca[pacitive electronic shutters like the R3, RTS Nikkormat etc are very reliable at all temperatures. Javier - --- Austin Franklin <darkroom@ix.netcom.com> wrote: > Javier, > > > I think the M6,7 etc are all analog! > > The M6 is all analog, no doubt, but the M6 I'm > reasonably sure they have > some simple digital circuitry in it. At least > that's how I would do it. > > How do you time the shutter in an analog system? > Somehow, you have to > measure time, to a pretty precise measure. It's a > LOT easier to do by > counting clock pulses...which would mean digital. > > > It's cheaper to build a non-emulative analog > circuit > > I disagree. Analog circuitry used for timing would > have to be calibrated, > and is very susceptible to drift and temperature. > Digital circuits for > timing are highly reliable, and maintain the "count" > over their temperature > range with exceptional accuracy. The only downside > to digital circuitry is > it's susceptible to low temperatures. > > I will ask Leica on Monday if the M7 circuitry is > all analog or has any > digital. I'd like to know. > > Regards, > > Austin > > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - forms, calculators, tips, more http://taxes.yahoo.com/ - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html