Wide primes on the SD1 -- Sigma, M42, Zeiss 2/35 T*Distagon ZS

In the pursuit of the perfect wide-ish prime for the SD1, I've been going through some various Sigma and M42 glass. I already had the 30mm f/1.4, which I've never been thrilled with, but I got it for next to nothing from a local secondhand shop at next to nothing after they found it next to impossible to move Sigma SA glass. Center sharpness is pretty decent, but sharpness falls off quickly towards the borders. The 18-50mm f/2.8 EX DC was decent on the SD14, but it's really showing its age with the SD1. Not terrible by any means, but not inspiring either. I did buy one new Sigma lens, the 20mm f/1.8, and it was alarmingly bad. I had to have received a copy with quality control issues, as it looked like it had a lensbaby effect! Returned that one, got a refund, c'est la vie.

Moving onto M42 glass, I had a few 28mm's laying around. Most were dogs, like the Formula One 28mm f/2.8, which is the softest lens I've ever used. Other notable lenses were the Vivitar 28mm f/2.5, the Tokina RMC M42 28mm f/2.8, and the Hanimex 28mm f/2.8.

No.

All lenses showed some green vignetting, though the Tokina was the most tolerable of the legacy glass. Unfortunately, the focus ring was very stiff, and this appears to be a common problem with this lens.

Enter the Zeiss 2/35 T*Distagon ZS. I ordered it new through Adorama at around $950 -- imagine that, a NEW M42 lens. Even with the box, I was surprised by this little lens. The first thing I see when I open the box is a hand-written quality control evaluation of the lens showing that this individual lens had met all the factory specifications. The lens itself is all-metal and solid as a rock. Focus is smooth, and the T* coating is so effective that it takes a close look to actually see the front element.

Sharpness is breathtaking. In our modern age of optics, almost all new lenses look "Good," or "Great," and then there are lenses like this Zeiss. It out-resolves the SD1 sensor, which is a good thing. Not only is it sharp, but it's dripping with micro-contrast and saturation. Chromatic aberrations are a bit of a weak point for the Distagon.

Unfortunately, mounted to the SD1 with a JTAT M42 mount, even this lens shows significant green vignetting at all apertures on the SD1. Before processing in Sigma Photo Pro 5.2, thumbnails appear distinctly green near the corners of the frame. On the SD1's LCD, some corners look bright, saturated green (But then, the LCD isn't the best for viewing images). Sigma Photo Pro actually does a decent job cleaning up the borders, and less-detailed portions of the images are corrected to proper color. Unfortunately, hard contrast transitions and edges retain their green cast, and sometimes processing in SPP actually exacerbates the problem. Shot on a Canon DSLR, the green does not appear even on harsh contrast transitions.

Overall, the Zeiss was a superb lens and could be a great lens for monochrome, or color with a bit of work in post-processing. Micro-contrast and sharpness were awesome and color in the center really popped. It's a lens with character. Build quality was awesome. If you can live with the green corners in some shots, you won't be disappointed.

Honestly, I didn't get much of a chance to shoot with this lens. I actually just sold my SD1 today -- I got a decent profit over what I paid for it used, and I wanted to use the extra cash to build my parrot a proper bird room. I decided to wait for the DP Merrills to hit the market. I use the 28mm and 40-50mm focal lengths almost exclusively, and the DPMs just make more sense for my particular needs (I absolutely love my DP2x, it's my main carry-around camera). Oh, also, I'm keeping the Zeiss for use on other cameras.

Photos will follow sometime this evening, I'm having some upload trouble with DPReview.

tl;dr: Sigma needs to make a good wide prime.