Tim Gray
Well-known
APO correction makes B&W images sharper. Same reason one might use APO enlarging lenses for B&W printing.
It’s just more of the same reason most non-APO lenses aren’t simple lenses, but achromats. If it didn’t matter for B&W, we’d all be shooting with single element simple lenses. That works okay if the source scene is (or recording medium is sensitive to) a single color (narrow band of wavelenths), but that isn’t B&W photography. Our recording medium might be monochromatic, but it is sensitive to many wavelengths of light which are out there in the world we photograph.
It’s just more of the same reason most non-APO lenses aren’t simple lenses, but achromats. If it didn’t matter for B&W, we’d all be shooting with single element simple lenses. That works okay if the source scene is (or recording medium is sensitive to) a single color (narrow band of wavelenths), but that isn’t B&W photography. Our recording medium might be monochromatic, but it is sensitive to many wavelengths of light which are out there in the world we photograph.
Tim Gray
Well-known
Also important, APO lenses are very well corrected for other optical aberrations as well. This can be desirable outside of color reasons.
james.liam
Well-known
Or put differently, colors/light wavelengths coming into focus fore and aft of the focal plane lowers overall contrast and acuity in B&W images as well. Perhaps more so.
Tim Gray
Well-known
Whether or not the gains are worth it is another discussion 
Finglas
Established
The new brass 35/2 Ultron II - looks very nice, I wish they would revise their 40mm lens to look like this. A small well made modern pancake 40mm F2 (even F1.8) in brass would be great. Afterall the Minolta Rokker and the Leica 40mm F2 are from mid 1970's while Cosina/Voigtlander own 40mm F1.4 is about 16 years now. It needs a new improved look, and this 35/2 points the way?
The new 35mm f/2 Ultron II's have arrived and are shipping.
New pics up soon.
The shiny black paint on brass barrel is beautiful.
Sean Reid just tested Version 1 (same glass as Version 2)
as sharper than the Leica 35mm f/2 Aspheric Summicron!
New pics up soon.
The shiny black paint on brass barrel is beautiful.
Sean Reid just tested Version 1 (same glass as Version 2)
as sharper than the Leica 35mm f/2 Aspheric Summicron!
Updated pics! Check the first post
All in stock and shipping except the FE 35mm F2 APO
which starts shipping April 9th!
All in stock and shipping except the FE 35mm F2 APO
which starts shipping April 9th!