[Leica] Home made lens focus check jig ($20)

[MGMcGough@aol.com]

From advice given to me by a local camera repair man, I have made a
usful lens focusing check jig.  I am sure that there are more sophisticated 
tools available, but for $20 I purchased a broken OOTGU sliding focusing
stage "M"  (the LTM is OOZAB*etc)  The lens is attached to it the same as 
to a camera but you focus on the built-in ground glass & check sharpness
with its 5X loupe against the distance scale of the lens or set it to any near
distance & replace the lens carefully back on the camera & see if the RF
matches up.

The worst thing that you can do is to photograph a test chart at say 10 feet
with a 135mm wide open (2.8-4) as the DOF is only inches & the resultant
photo might be soft while only inches away be sharp as a tack - unless the
film plane to lens distance is dead on.

As much as I prefer the "M" to the "R", I switch to my R7 for lenses longer
than 90mm, although I have taken many sharp pics with the 135M - but the
lenses have all been checked out & nothing taken for granted.

Mary Grace