The Nokton 17.5mm f/0.95 is one of the nicest Micro Four Thirds lenses and it just got reviewed by the Spanish DSLRmagazine (Click here for the google translation). The reviewer Valentin Sama is impressed by the lens quality. Already at full f/0.95 aperture the resolution is very good. You get the highest resolution at f/5.6. The lens has no weakness, it means center and border resolution are on high level at all apertures. A weakness may be the high vignetting at full aperture which is not surprising for such a fats lens. Vignetting almost disappears from f/2.0 upwards. Distortion is negligible if the subject is distant from the camera. Closer you get to the subject more distortion you will see. There is little CA (Chromatic Aberration) and little Astigmatism. In sumamry it’s a pretty soldi lens that is even better than the (alreayd good) Voigtländer Nokton 25mm f/0.95.
I think Voigtländer deserves a lot of praise for the two lenses they made for the m43 system! it’s really not easy to find lenses like this (with a high quality and decent price) in any other system (DSLR or Mirrorless)!
So, where to find the 17.5mm lens in Stock? First look at eBay (Click hee to see all acutions). You can find plenty of stores selling the lens. Also BHphoto (Click here) has it in Stock (from June 1st).