[Leica] 21 SA does work on an M8

[red735i at earthlink.net (Frank Filippone)]

Thanks Don..... I think you did a good test.  Blank walls are adequate test 
subjects... Another and slightly better test subject is
an outside wall of a brick building on a really overcast day.  The overcast 
will create even illumination, and the brick wall is
pretty tonally the same over large areas.

Correct me if I am wrong, but there is no way to enter the FL data into the 
M8 except by the lens ring coding or faking out that
system using a magic marker.....  So the picture was taken with no 
correction for light angle of attack on the sensor.

However, and this is more theoretical, since I am far removed from owning an 
M8.....

The 21 SA ( in fact all SA lenses, regardless of coverage) have a very deep 
hourglass shape.  That puts the rear of the lens close
to the film plane, and the light rays at a very strong angle to the film.  
Not at all perpendicular.  In effect, it should show the
most significant vignetting of any lens on a M8, assuming all the stories 
about angle of attack on digital sensors are correct.....

So I will just say that I am confused.....

Delighted you are happy with the results...... buying something besides the 
SA at 21mm would hurt!

Frank Filippone


I was shooting a pretty blank wall and the vignetting was not noticeable.  I
assume it is the design of the sensor and the crop factor taking the outer
bits out of consideration.  On film I could always notice some darkening of
the corners.

Don