What is the voigtl nder color skopar 21mm f 4 p good for?

Here is what the site says about that.

From Voigtländer Color-Skopar 21mm f/4 P: Voigtländer Color-Skopar 21mm f/4 P: A prime lens by Voigtländer for Full frame cameras, 21mm f/4. Specs - Maker: Voigtländer - Focal length: 21mm (prime) - Maximum aperture: f/4 - Made for: Full frame sensors - Mounts: Leica M - Stabilised: no - Autofocus: no, manual focus What it frames like - On full frame (Leica M): as marked, 21mm. Cameras it fits - Leica M9: Full frame - Leica M9-P: Full frame - [Leica ...

From Voigtländer Color-Skopar Vintage Line 21mm f/3.5 Aspherical: Voigtländer Color-Skopar Vintage Line 21mm f/3.5 Aspherical: A prime lens by Voigtländer for Full frame cameras, 21mm f/3.5.

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