This is a timely thread as I'm thinking about this lens and the Voigtlander Color-Skopar 25mm f/4. I'm leaning toward the Zeiss because of it being 2.8, but love the compactness of the Voigtlander.. I normally shoot 35/50 what frame lines does this lens bring up on an M9 or M6? How easy is it to use it without the external viewfinder?
I used a Voigtlander 25/4 for over a year before finally finding my local dealer had a used one in great condition for a great price (i like to buy from Red Dot where i can). I wish I'd just bought the Zeiss from the start.
The Skopar is a lovely lens for it's price, very small, sharp, but nothing on the Zeiss. The Zeiss is bigger, but it's well worth it. On brightness, edge to edge performance, distortion and outstanding sharpness. It's been like upgrading my sensor, the detail at f8 only gives in when the sensor starts to pixelate.
With regards the use without a viewfinder, if you don't want to use one on an M9, I'd suggest getting the 28mm and using the framelines. There is a fair portion outside the visible frame and it has nothing on the Zeiss viewfinder.
Also, i can't recommend the Zeiss 25/28 viewfinder enough. It's bigger, brighter and just better, than all other OVFs, including the Leicas. The Leica 24mm (metal) is like looking down a dark tunnel in comparison. The Zeiss is brighter than the built in viewfinder and actually makes the M9's built in one looks dark and murky when switching back and forth for focus.
As a result, I will be changing my other viewfinders (15, 21) to Zeiss ones as and when i can.
This is my setup.
Weekend Camera Porn / Leica M9 + Zeiss 25mm f2.8 Biogon by
Cris Rose, on Flickr
Weekend Camera Porn / Leica M9 + Zeiss 25mm 28mm Optical Viewfinder by
Cris Rose, on Flickr