Considering the 1.25x conversion factor, a 35mm on the S2 is equivalent to a 28mm on the M7 for an identical view angle so I did a quick dirty comparison between the 28mm Summicron-M and the 35mm f/2.5 CS by overlaying the MTF charts of both lenses at f/2.5(f/2.8) and f/5.6.
Blue lines are for the 35-S and red lines are for the 28-M-Cron, horizontal axis of the M lens has been scaled to about 74% of the S lens horizontal axis so you can see the M lens edges at 20mm and the S lens edges at 27mm.
Performance wise, they are almost identical in terms of contrast, resolution at f/2.5(f/2.8) are quite similar, the S lens has an edge in resolution at f/5.6 ... but that's not a surprise if the test target is the same, at an identical view angle the larger format lens of the same optical quality is bound to produce some higher resolution numbers.
A brand new 28 Summicron-M ASPH. is asking for US$4000, adding auto focus and a leaf shutter for larger format, how much would you bet on the 35/2.5 S lens?
I'm guessing its price would be around $6000-$8000 US, adding the cost of the body, 15000 Euros at least (based on reports from the Kina '08) - roughly 21500 US$ ... that's about US$30000 to kick start.
Must be the best bang of your bucks ... when I hit the powerball jackpot, I will also jump on board.
