Had the privilege to borrow a 50mm APO-Summicron lens over the weekend from my dealer. Went for a short walk across our fields nearby.
Wow… this lens is really amazing. Hardly any distortion, great colours, super contrast and it is extremely sharp from corner to corner , yet able to give some really nice bookeh. Some seem to say it is getting close to the Noctilux, but to me you can easily distinguish the two. The Noctilux is able to give some fantastic almost like 3d effects. The hood is built in (twist and turn) and butter smooth. Contrary to the hood on my Noctilux which is sometimes involuntarily collapsing while carrying it, the mechanism on the APO-Summicron is definitely better. While carrying it around there was never a problem that the lens hood would collapse.
The aperture ring is way too loose to my personal liking, even a light touch will change the aperture, e.g. when you use gloves and focus and only so slightly touch the aperture ring… The focusing ring is firmer e.g. than the 35mm Summicron I have, but not too firm, actually quite good.
All in all great “little” lens, I enjoyed using it very much today, even it was only for 2 hours