Voigtlander 20 mm f/ 3.5 Color Skopar SL II Lens

Compact all metal body, smooth focus ring, electronic aperture control. Small filter size (52mm).

Weaknesses:

Strong corner vignetting, weak corner sharpness. Chromatic aberration present in high contrast areas. Some barrel distortion.

Comments:

I also own the old Canon EF 20mm f/2.8 USM (I used two copies of this lens). The Canon is sharper in the center than the Voigtlander, corner sharpness is similar on booth, and vignetting is better controlled in the Voigtlander. Booth suffers from chromatic aberrations in high contrast areas, stopping down helps a bit but doesn't solves the issue.

Stopped down IMHO the Canon has a slight advantage over the Voigtlander across the frame in overall sharpness.

Manual focusing is not an issue with the Voigtlander, a 20mm focal length has a wide depth of field, nothing to worry about, no need to use a high precission focus screen.

But when it comes to portability, the Voigtlander wins. If you want to carry severall primes this small 20mm pancake lens is very nice to have.

I currently have loaded in my bag with a Voigtlander 20mm, Canon EF 40mm, Canon EF 135mm (all 52mm filtersize diameter