Would you believe these two lenses have the same specs? 35mm, F:1.4. Mild wide-angle, big/fast aperture.
580g vs 200g.

(I got the pic from
tOP.) Now, the Canon lens (which is excellent, I have it) is designed for a DSLR, which means that the optical design has to compensate for the fact that due to the mirror in the camera, the lens can't get as close to the sensor as it would naturally be. But I'm curious if this fact alone can justify such a huge size/weight difference. (Of course the quality of the Voigtländer lens is to be considered, I have not seen a comparison.)
Update: There's been cast doubt that the picture is exactly to scale. On the picture, the relationship is 1:4 in length, but the numbers given on the site are 1:3.