Donald Qualls
7-Jan-2006, 23:08
I've just purchased a Schneider Componon 150 f/5.6, in nice working Synchro Compur with accurate aperture scale, for what I think was a good price; this will be used on my recently acquired Aletta 4x5. I'm aware this was originally made as an enlarging lens, but I've also seen references to the Componon and Componon-S as taking lenses; the Componon-S is said to be similar to a Symmar (including, in this length, converting with rear group only to a 265 f/12), and there are many enlarging and process lenses that do work well at infinity focus, especially if stopped down.
My question is, how would I go about testing the front and/or rear groups separately using only film, enlarger, and 2400 ppi scanner? Or is use of the lens in "converted" mode a matter of whether it's "good enough" for my needs? Are there significant optical differences between the Componon and Componon-S that might affect my ability to use the rear group (or the front group, for that matter) in "convertible" form, things like field curvature, coma, etc.?
My question is, how would I go about testing the front and/or rear groups separately using only film, enlarger, and 2400 ppi scanner? Or is use of the lens in "converted" mode a matter of whether it's "good enough" for my needs? Are there significant optical differences between the Componon and Componon-S that might affect my ability to use the rear group (or the front group, for that matter) in "convertible" form, things like field curvature, coma, etc.?