I did a comparison of the M-Rokkor 40, Summarit 35/3.5, Summicron 50 (IV), Canon 50/1.2 and a Summarit 75/2.5 (+a Jupiter 8, which was just awful) yesterday. The method was shooting a newspaper hung between two stands with the camera (M9) on a tripod (lenses shot wide open, at f2, f2.8 and f5.6).
I need to reshoot the 75 as my focus was off, but here are the quick results with the other four:
- M-Rokkor was clearly the sharpest of the lot in the centre at f2.8 and f5.6, ok in the corners at f2.8 and maybe the best in the corners at f5.6
- Summarit 35 was not the best at anything, but perhaps the most balanced, showing the least difference between wide open and f5.6
- Summicron was by far the best in the corners wide open and at f2.8. A really good lens, which comes as no surprise, but I did not expect it to lose to the M-Rokkor in the centre!
- The Canon is a trick lens. It's just fine at f5.6, but it is in the wrong place in a sharpness test as it is all about the bokeh.
Caveat: my focus accuracy test showed that there is slight back focus (maybe 2-3cm at a distance of 1.2m) with the Summicron and the 75 on my M9, which is why I need to reshoot the 75. I will also do a bokeh test at some point, when I get around to that.
Conclusion: I was expecting the Summicron to beat the pants off the Summarit 35 and the M-Rokkor, but this did not happen. The M-Rokkor was so good, that I might sell my 35, and considering the cost of that lens, it was the winner here.
I can do this with images if there is interest.
