Compare lenses

Sigma 20mm f/2 DG Contemporary vs Zeiss Loxia 21mm f/2.8

The Sigma 20mm f/2 DG Contemporary and the Zeiss Loxia 21mm f/2.8 side by side, computed from this guide's catalogue.

Which to pick

Pick the Sigma 20mm f/2 DG Contemporary if you want a brighter f/2 (1.0 stops more light), for dim light and softer backgrounds; autofocus; and a fit on more cameras (66 against 41 in this guide). On these specs the Zeiss Loxia 21mm f/2.8 has no clear advantage: choose it if the price, the handling or a lens you own decides it.

Still torn? Ask the guide about the Sigma 20mm f/2 DG Contemporary and the Zeiss Loxia 21mm f/2.8

Specs side by side

Rows that differ are in full colour; the better value is marked where one is better by any measure.
Spec	Sigma 20mm f/2 DG Contemporary	Zeiss Loxia 21mm f/2.8
Maker	Sigma	Zeiss
Focal length	20mm (prime)	21mm (prime)
Full-frame equivalent	20mm	21mm
Maximum aperture	f/2brighter	f/2.8
Made for	Full frame	Full frame
Mounts	Sony E, L-Mount	Sony E
Stabilised	no	no
Autofocus	yesautofocus	no, manual focus
Weight	370 glighter	394 g
Cameras it fits	66 in this guidefits more cameras	41 in this guide

Focal range, in full-frame terms

Sigma 20mm f/2 DG Contemporary: 20mm.

Zeiss Loxia 21mm f/2.8: 21mm.

Aperture

Sigma 20mm f/2 DG Contemporary: f/2 wide open.

Zeiss Loxia 21mm f/2.8: f/2.8 wide open.

Each opening drawn to scale against f/1.4: a smaller f-number lets in more light and blurs the background more.

Field of view

How wide each sees, at each end, on the sensor it was made for.

Cameras they fit

41 cameras in this guide take both, so either works on the same body. In all, the Sigma 20mm f/2 DG Contemporary fits 66 and the Zeiss Loxia 21mm f/2.8 41.