Summary: The Leica APO-Summicron-M 90mm f/2 ASPH. is a nearly flawless telephoto lens for Leica rangefinder cameras. It's sharp from edge to edge and has a wide f/2 maximum aperture. Due to the price this is a big commitment and would be worth checking this Carl Zeiss Lens to compare: http://amzn.to/1wkakTh
Excerpt: Relative to Leica glass, this lens is a bargin. As a former Nikon shooter (>35 years)this is far superior to the 105mm f1.8 or the 400mm f2.8 or the Mamiya 250mm I previously used. I am blind as a bat and I can focus this lens without diaopter modification or magnification.
Pros: Durable, Nice Bokeh, Rugged, Strong Construction
Excerpt: This is a wonderful lens...but my 90mm f/2.8 Elmarit is as good or better with definitely better bokeh....although the extra stop is worth having when you need it... And the admittedly very expensive Pentax 85mm f/1.4 FA* AF is better for real world IQ. Would I sell it? No...
Pros: Consistent Output, Durable, Rugged, Strong Construction
Excerpt: I wanted to use this lens for portraiture with very shallow depth of field. After shooting some film and digital pictures with it, I'm also looking for other subjects that will be appropriate for this lens. I like it so much. It's tack sharp when you nail the focus at widest aperture.
Excerpt: Pros: - Great portrait lens with beautiful bokeh - Optical quality is excellent - Collapsible lens hood is practical Cons: - Even though this lens is marked as APO, there are traces of axial chromatic aberration - Focusing at f/2 with M9 is not always reliable due to shallow depth of field
Excerpt: This is an amazing lens and I'm surprised so little is written of it. It has a beautiful glow when opened up along with sharpness. It's a lifetime lens worth owning and keeping like a family heirloom. I love it on my M5 and M9. It' is not heavy by SLR standards.
Pros: Consistent Output, Durable, Nice Bokeh, Rugged, Strong Construction
Excerpt: I think this is probably the best lens I've ever owned having been photographing for 27 years with many different types of cameras. This is a jewel that I'll always have. People say "heavy" but compared to an SLR lens it's not heavy.
Pros: Consistent Output, Nice Bokeh, Strong Construction