Archived posting to the Leica Users Group, 2002/03/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Can someone explain what in non-technical terms what "parabolic mirror" is? - --- John Collier <jbcollier@powersurfr.com> wrote: > All I can say is that I have had a late M4-2 camera > with no rangefinder > flare problems. It was exactly like my M2. I also > have an early M4-2 that > flares exactly like my M6TTL. Others have reported > M4-P cameras that did not > flare like their M6 cameras. If it was a different > mirror shape then it > would be consistent from a certain point in > production. > > John Collier > > > From: Dr.Alexander.Kraus@gmx.de > > > > Hi Lugers, > > much has been speculated about the rangefinder > flare problem in late M4-P > > and M6 (TTL) > > cameras. Recently, I found an interesting posting > in the Leica customer > > forum, where someone stated that the reason for > the whiteout of the > > rangefinder > > patch would be the switch from a flat mirror (for > brightline illumination) to > > a parabolic one. The latter one would give > siginifcantly brighter frames, > > however under certain light conditions, the light > would be focussed directly > > on > > the rangefinder hole of the frame mask mechanism. > > This sounded very reasonable to me and so I > decided ton ask Leica directly > > whether above explanation is correct. Yesterday, I > received an email from Mr. > > von Gyimes from Leica. He wrote: (Translation > behind the citation) > > > > SNIP > > > > It is correct that the rangefinder (patch) flare > problem is caused by the > > parabolic mirror. > > Under certain light conditions (110° to the light > source) the rangefinder > > patch can become bright white and unusable. > > This problem was significantly reduced by > introducing a second reflective > > surface in the M7 and M6 TTL, but it was not yet > possible to eliminate it > > completely. > > However, we are working on a solution and we are > confident that it will be > > introduced at the Photokina 2002. > > The coated viewfinder windows of the M7 enhance > the contrast of the > > viewfinder image visibly. In fall 2002 it will be > possible to upgrade Leica > > M6/M6TTL > > cameras with these windows. > > > > > > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html __________________________________________________ Do You Yahoo!? Try FREE Yahoo! Mail - the world's greatest free email! http://mail.yahoo.com/ - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html