Re: FM Rolling Review: Voigtlander 110mm f/2.5 Macro APO-Lanthar
All of the CV 110/2.5, CV 125/2.5, Zeiss 100/2 MP, Leica 100/2.8 Apo, Sony 90/2.8 are very fine lenses, so the perceived advantage of switching may not be great enough for everyone.
In my case an AF lens is much better for portraits than an MF lens. Then there is the subject of focus throw, where I prefer old school long focus throw for landscape, and both of the CV 65/2 and 110/2.5 have a too short focus throw for my taste, so I find them fiddly for landscape. For macro I find AF to be useful. In addition the Sony 90/2.8 allows MF both with a rather classical focus ring with a scale, and you can do modern style focus by wire, that so many don't like. Modern style focus by wire can be learnt, and then you can reap the benefit of an enormously precise focus mechanism with a very long focus throw, which is great for landscape. If the CV 110/2.5 had a much longer focus throw from 5 meters to infinity, I would be much more positive about using it for landscapes photography. This could make it less of a niche lens, imho.
Optically the CV 110/2.5 is of course top drawer, but it's not alone in that category, and there are more lenses that are optically great, like the Sony 90/2.8 G. I'd like to see an apochromatic macro lens with a better thought out focus throw to easier harness its optical capabilities. AF would be nice too, but perhaps not realistic.
Regarding LoCA the Sony 90/2.8 G is much better corrected than lenses like the Nikon AF-S 105/2.8 VR and Zeiss 100/2 MP. It's the poor correction of LoCA in those two lenses (Nikon and Zeiss) that originally made me interest in apochromatic lenses, and at the time those were the CV 125/2.5 and Leica 100/2.8 apo. The level of correction in the Sony 90/2.8 G is so good that I see no need to give up AF, eye-AF or the choice of short or long focus throw through either focus scale (short) or through true focus-by-wire (long).
There are two ways of switching the Sony 90/2.8 G to MF, if you leave the focus ring in the AF position and switch to MF in the Fn menu you get a much longer focus throw than if you pull the focus ring to the MF position. In addition the focus scale can be adjusted to a predetrmined distance, so you can switch from AF to a preset distance by pulling the focus ringvto the MF position. Lots of goodies here, imho.
