Is the voigtl nder nokton 21mm f 1 4 aspherical good for astrophotography?

I don't have anything on this site that covers astrophotography, so I can't give you a verdict on it for stars or the Milky Way. What the lens page does say: it's a 21mm f/1.4 prime for full frame, made for Sony E and Leica M, with manual focus and no stabilisation. On a full-frame body that's a wide view with a fast aperture, and f/1.4 lets in plenty of light.

Manual focus and no stabilisation are the things to check before you rely on it for night work. You'd be focusing by hand, and you'd want a sturdy tripod. The landscape page covers wide lenses for open scenes, and the Lenses page explains how focal length and aperture shape what you can shoot.

Written by Claude from this site's pages.