Compare lenses

Sigma 20mm f/2 DG Contemporary vs Tamron 20mm f/2.8 Di III OSD M1:2

The Sigma 20mm f/2 DG Contemporary and the Tamron 20mm f/2.8 Di III OSD M1:2 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 and a fit on more cameras (66 against 41 in this guide). Pick the Tamron 20mm f/2.8 Di III OSD M1:2 if you want a lighter lens (220 g against 370 g).

Still torn? Ask the guide about the Sigma 20mm f/2 DG Contemporary and the Tamron 20mm f/2.8 Di III OSD M1:2

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	Tamron 20mm f/2.8 Di III OSD M1:2
Maker	Sigma	Tamron
Focal length	20mm (prime)	20mm (prime)
Full-frame equivalent	20mm	20mm
Maximum aperture	f/2brighter	f/2.8
Made for	Full frame	Full frame
Mounts	Sony E, L-Mount	Sony E
Stabilised	no	no
Autofocus	yes	yes
Weight	370 g	220 glighter
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.

Tamron 20mm f/2.8 Di III OSD M1:2: 20mm.

Aperture

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

Tamron 20mm f/2.8 Di III OSD M1:2: 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 Tamron 20mm f/2.8 Di III OSD M1:2 41.