Re: Eye Piece Corrective Lenses

[Michael Goldbard <m@gbard.com>]

Richard,

Thanks for the informative posting.  Perhaps you or another LUGger might be
able to answer some related questions.

At one time Leitz sold astigmatic corrective lens and I believe that they
were supplied in a rotating mount.  The rotation enabled the M camera user
to maintain the proper orientation of the corrective lens when using the
camera in a horizontal or vertical position.

From what I've read, it appears that only a blank mount is now supplied.
Does the blank mount rotate in the same fashion as the previous astigmatic
corrective lenses?  Is such a lens convenient or does the necessity of
rotation disturb the  flow of shooting?

Thanks to all for the making the LUG such a great resource.

		Michael


Richard Clompus wrote:

>With astigmatic corrective lenses, you must not only deal with the strength
>of the lens but also the orientation.  Orientation is described as the axis
>and is expressed in degress (starting at 0 and going up to 180.)  An
>astigmatic prescription is then expressed as -1.00 diopter X 180 so that it
>describes the strength (-1.00 diopter) and orientation (axis 180).  The
>astigmatic eye piece corrective lens must be turned and locked into the
>correct position.  If it gets turned even 10 degrees from where it should
>be, your vision will be blurred.  Make sure that the eye piece is marked so
>you know the final orientation on the camera.  This way the optician can
>insert the lens so when you tighten the eye piece ring, it lines up the
>proper way.
>