Archived posting to the Leica Users Group, 2000/01/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Gaifana@aol.com wrote: > I would like to take this opportunity to cross-examine both of you regarding > some statements made here. Nothing serious - just technical questions. Either > one of you can jump in on any of them. > > Erwin (first) - I read your rangefinder accuracy piece last night. Very > interesting article. Compliments. I went through the various tables. I > noticed that first you showed a table of critical apertures for various focal > lengths. > > 1. At what distance is this table made? Is it different at infinity (where > you later say focus error is great) and at one meter? > > 2. If the critical aperture table shows that even M3s cannot focus some of > the Leitz lenses, is it that great a way of determining what type of base > length you need? > > Then you presented another table, which showed minimum base lengths to focus > various lenses, using an equation provided by Leica. > > 1. Could you reveal what formula you use? Does it take distance into account? > > 2. How do you justify some of your Hexar RF prerelease attacks when your own > table showing needed EBL (which later you admit is a better system - and I'll > concur... if it's good enough for Leica, it's good enough for me) shows that > it is capable of focusing both the 90/2 Summicron and the 75/1.4 Summicron? > Assume that the rangefinder is in all respects identical to the 0.72x M6 > except the magnification. > > And now one very basic two-part question: > > 1. Can you make up for a deficiency in real and effective base length by > slapping an eyepiece magnifier on the camera, i.e. can you put an FM-10 > eyepiece magnifier on a Bessa-R and get away with using longer or faster > lenses with a 30mm length? > > 2. As a corrollary, if you have a camera with a 69mm BL (let's say an M6 > 0.72x), but the effective length is too short, can you do the same thing? > > Now, Steve, this is a deceptively-simple one: > > What is an affordable entry-level Leica? You mentioned this in reference to > the planned M-mount Cosina. The M6 is a pretty basic camera, feature wise, > and I am curious as to how you would strip it down. > > Cheers > Dante Dante, I hope you don't mind if I put some of my thoughts in to your question to Steeve. An entry Leica range finder could have the following features: Keep the M-type body. (most important to keep the feel) Remove the protection pads above the strap lugs No light meter. This should simplify the view finder too. (The new Cosina Voigtlander) light meter could be used. No TTL flash provision Get rid of the film speed reminder on the back. Put a simple pocket for the film box lid on to the back No provision for motor drive No self timer Change the automatic frame insertion to a simpler manual system. The frames are only 35,50 and 90mm. Release a ridged (less expensive) 50mm f2.8 lens. -- I can see no reason why a lousy 4 element lens should cost as much as the Elmar does -- Black or chrome only, Which ever is less costly. Use an M3 type rapid wind lever (made out of one part only) Make it available to Photographic institutions and schools with a reduced price, to try and make it in to a standard camera like the Pentax K1000. None of the above should reduce the quality of the camera. I can't see that it should cost an arm and a leg to develop a body like this. Except the Film reminder pocket, there are no new items. Not drilling a few holes( missing preview lever etc.) should save some more. This is still a perfectly usable camera. It just hasn't the whistles and bells of the M6. I believe Leica could make less expensive standard lenses (50mm). Even an F2, with slightly relaxed specifications should be possible. (95% of users would not know the difference or would not care) Regards, Horst Schmidt