The Voigtländer SL (series I) lenses with silver/black barrels and the easily distinguishable Red/Green/Blue stripes are long since discontinued. While they've all certainly drawn attention due to the outstanding 125/2.5 Macro APO Lanthar, none of the others are as outstanding as the 125/2.5 (the 180/4 comes close though). They all however are finely crafted, metal construction and they all share a common character - very pleasing rendering of out-of-focus areas.
The 180/4 IMO ranks #2 in this "family" that consists of the 12/5.6 Aspherical (mirror lock-up), 15/4.5 Aspherical (mirror lock-up) and the "normal" 40/2 Aspherical, 75/2.5, 90/3.5 APO, 125/2.5 APO and 180/4 APO. Save some time and I'll add photos and thoughts about the other members of Voigtländer's SL series for Nikon (later).
(subjective quality ranking)
#1 125/2.5 Macro
#2 180/4
#3 (not far behind) 90/3.5
#4 40/2
#5 75/2.5
The 180/4 is one of those lenses your motoric memory has to learn and master, because it shares a common design factor with all the SL lenses: the focus gearing is optimized for close-up use, making them really easy to handle at close to medium distances, but very bitchy near infinity. They all come from the factory adjusted so that you can focus them "past infinity". I spent lots of time last decade (bought most of mine new) with live-view, a tripod and carefully fine-tuning focus to get optimum sharpness at infinity. Of course that's not a big issue with the 40/2 (because of DoF) but with the 180/4 especially you will curse a few times before you learn that you can't just focus it until it "infinity stops" and then compose.
That said, I thoroughly enjoy this lens. I always have, ever since I bought it new from Steve Gandy about 10 years ago. It paints very delicate look in images and it was long my Zen practice as I practiced with it going at everything from butterflies to dogs trying to nail focus manually (and eventually I did master it). I picked up the lens today after a long break in using it, and wow was I pleasantly surprised how my motoric memory remembered exactly how much to turn it to nail focus.
Anyway, here are some samples of the look you can expect, should you find it. Beware though, of all the SL lenses manufactured in Nikon Ai-S mount, it is the most rare - production run is likely no more than 1,000 copies based on the serial number spacing*. Should you find one on eBay prepare to pay 800-1100 EUR, which is almost twice what a lens of this quality, focal length and aperture should cost IMO...
* source: my own "mini-project SL serials" inspired by Roland Vink
http://forum.mflenses.com/voigtlaender-sl-apo-lanthar-serial-numbers-production-volumes-t24547.html
