Lens review

Leica Summicron-M 50 mm f/2.0

9. Ghosting, flares and transmission

Leica Summicron-M 50 mm f/2.0 works very well against the bright light. After heavily stopping down the lens, it’s hard to catch any light artifacts in the picture. Basically, only around the maximum aperture can we get an arc of a large diameter and slight intensity, spreading through much of the picture.

Leica’s transmission results presented below clearly show it’s been optimized for the center of the visible spectrum. In quite a wide range from 500 to 600 nm the lens reaches transmission of about 95%. It’s a very high result, but not hard to get when we take into consideration the fact that Summicron only consists of four groups of lenses, so has 8 light-glass boundaries to cover with coatings. It means that on one boundary we lose about 0.6% of light. Not much, but we should expect about 0.2-0.3% from Leica.