Hektor 13.5cm f4.5 on Canon 5D II. Click for larger.
This is probably one of the cheapest Leica M-mount lenses you can buy, and for a good reason; it's not the sharpest lens, especially in the corners. I do have another Hektor that is a complete lens and I used it on the NEX and the result is similar. This one is probably much worse, the way I mounted it on the 5D II, with glue, filter rings, and all. But, it's how much fun you have shooting it that matters!
Fall Colours - Canon 5D II & Leitz Hektor 13.5cm f4.5. Click for larger.
One thing that I notice is that the Canon has a much stronger, more vibrant colours without much processing. I kind of like it as I prefer vibrant colours; much more pleasing to my eyes. One advantage of mounting the lens on a helicoid, is that it lets me focus much closer than otherwise possible. Being able to focus close is one of the attractions for me, as I do a fair bit of close up pictures.
Seagull - Canon 5D II & Leitz Hektor 13.5cm f4.5 @ f4.5. Click for larger.
I certainly enjoyed shooting this lens, and was nice not having to worry about adapter tolerance, as I am sure mine is way off the chart. There are times when sharp corners are needed, but many pictures are simply enhanced by the lack of sharp corners.
Sign of Autumn - Canon 5D II & Leitz Hektor 13.5cm f4.5 @ f4.5.
Texting - Canon 5D II & Leitz Hektor 13.5cm f4.5