[Leica] Questions for Steve AND Erwin re new rangefinders

[Gaifana@aol.com]

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