Re: FM Rolling Review: Voigtlander 110mm f/2.5 Macro APO-Lanthar
Hi Fred,
I think you may have it backwards.
Apochromats converge 3 primary colours at the plane of focus (no lateral CA) and have negligible spherical aberration. That is of course the typical expectation. I've owned plenty of 'APO' lenses with lots of axial CA (Leica 90 APO springs to mind) but I can't think of one that displayed lateral CA in the plane of focus.
Zeiss say both should be corrected before a lens is considered APO but the 135/2 APO-sonnar has loads of longitudinal CA.
Fred Miranda wrote: secondclaw wrote:
Is this something to be expected from these lenses? Not too big of a deal, just wondering as I've never owned APO lenses before... or - could it be sensor cover on the camera possibly doing this?
APO promises to cure axial CA (Longitudinal) and not lateral CA. That's what you are seeing in your image. This color aberration shows up off-axis and does not really go away even when stepping down the aperture. With the CV 110/2.5, it's very low and only present under extreme conditions.
