[MF3D.FORUM:513] Re: Exact fl match for paired lenses.

["Bill Glickman" <bglick@xxxxxxxx>]

     Thank you list members, specially David and Greg for your persistence
in helping me match a pair of 80mm lenses.  Anything one does for the first
time is a bit confusing, specailly this!

      My test results were not perfect, but I am unsure if the error amount
is acceptable, or falls within the guidlines discussed.  I am unsure how to
convert the distance my grid lines are off into percentages discussed
earlier.  I am not sure what the error is a a percentage of....

     I conducted the test as follows.  I shot a grid on the full 6x7 frame.
The grid was made with pen lines running vertical and horizontal.  I shot
with the first lens, then without moving the camera, shot with the second
lens.  I layed the chromes on top of one another on a light box and lined up
the girds.  I lined the top grid lines up... but could not keep the bottom
lines aligned.  (both horizontal and vertical would not align).  I looked
through a 10x loue with a measuring gauge attached  determine how far off
the lines were towards the bottom of the chrome.  The worst lines needed to
come together by .15mm to be perfectly aligned.

    I shot some 3d shots with these lenses and I think that the corners go a
bit soft... meaning the center was tack sharp, but in the corners, reading
text on some boxes was more difficult to read then the box in the center,
but still legible.  Of course I was afraid my mind was playing tricks with
me after I already knew the grids did not match up perfectly.

       So how does my results measure up?  Are they excellent, good, fair,
poor, or not a useable pair?  Thank you again.

Regards
Bill G