Archived posting to the Leica Users Group, 2002/09/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Sun, 29 Sep 2002, John and Catherine Allen wrote: > > I've looked inside the one I just bought, and I can't see any sign of an > autofocus mechanism, but I'd like to ask - can anyone explain what a > Pradovit autofocus mechanism looks like? I believed - possibly wrongly - > that some kind of reflective beam (infra-red?) was bounced off the front > surface of the slide, and that there was feedback from this to the lens > focusing motor which moved the lens in or out by a small amount to keep > the lens to slide distance constant. > > If this is correct, presumably a Pradovit with autofocus will have a small > extra gadget somewhere near the slide. What should I look for? > > John > > -- > > John and Catherine Allen > Bofferdange, Luxembourg > allen@vo.lu > http://www2.vo.lu/homepages/allen > > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html > John, As one looks at the front of the projector with the cover off, there is a light source on the left side of the lens aimed at the slide and a photoreceptor in a shroud on the right, both at a 45 degree angle. There is a circuit card mounted vertically to the right of the lens to which the photoreceptor is wired. John Nebel - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html