[Leica] M eyepiece correction lenses

[Herbert & Lee Kanner <kanner@acm.org>]

In the case of the M, I believe that the eyepiece as manufactured 
puts the virtual image out at infinity (lots of cameras don't).  If I 
am correct, and this supposition worked for me, then the corrector 
lens you want is the one that comes closest to your prescription in 
diopters.

The reason I say this is that I bought a corrector at the infamous K 
& S in Palo Alto.  I checked it out by looking through my glasses at 
a distant object and rapidly switching between my glass and the 
eyepiece correction lens.  The idiot clerk insisted that you couldn't 
do it that way and ran off to find a Leica; I hadn't brought mine. 
Of course, when he found one, the corrector that I chose seemed ok 
when screwed into the camera, but in my opinion, my ability to judge 
through the camera was not as critical as the way I had been doing 
it.  The clerk kept protesting and I finally had to shut him up by 
telling him that my graduate degree was in physics and that I knew a 
wee bit about optics.

To add injury to insult, their price was $99 for that bit of glass. 
To bad I hadn't checked first with B & H, whose price, if I remember 
correctly, is $72.

Good luck,

Herb


- ----------Original Message----------------

I'm a little fuzzy on the question of selecting a correction lens for the
M6 eyepiece. Is there a way other than trial and error to determine which
one is most appropriate? The range of potential dioptre adjustment seems
to be very broad and I'm certain that I fall somewhere in there, but is
there a way based on my eyeglass prescription to tell which one of the
alternative lenses would mesh best with the uncorrected eyepiece?

Thanks for your help. Probably a dumb question.

Daniel Bowdoin
- -- 


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