Quick answer
The Sigma 21mm f/2.8 Super Wide II is a ultra-wide prime lens covering 21mm at f/2.8 for the Sigma SA mount. Its bright maximum aperture handles indoor and evening light reasonably well.
About this lens
This 21mm f/2.8 wide-angle prime lens from Sigma fits Sigma SA mount cameras. The wide view suits landscapes, architecture and environmental shots.
Sigma 21mm f/2.8 Super Wide II specifications
What can you shoot with the Sigma 21mm f/2.8 Super Wide II?
At 21mm this is a ultra-wide prime, which typically suits:
- Landscapes and big skies
- Architecture and interiors
- Astrophotography and night skies
Its bright maximum aperture handles indoor and evening light reasonably well.
Full-frame equivalent and field of view
Calculated from the focal length and crop factor. Not measured.
| Sensor | Crop | Equivalent | Horizontal FOV | Diagonal FOV |
|---|---|---|---|---|
| Full frame | 1.0x | 21mm | 81.2° | 91.7° |
| APS-C | 1.5x | 32mm | 59.5° | 69° |
Frequently asked questions
What mount does the Sigma 21mm f/2.8 Super Wide II use?
It uses the Sigma SA mount, so it fits Sigma SA cameras directly.
What is the focal length of the Sigma 21mm f/2.8 Super Wide II?
It is a fixed 21mm lens with a maximum aperture of f/2.8. That makes it a ultra-wide lens.
Is the Sigma 21mm f/2.8 Super Wide II a prime or a zoom lens?
It is a prime lens with a fixed 21mm focal length. Primes usually open wider than zooms; this one opens to f/2.8.
What is the Sigma 21mm f/2.8 Super Wide II equivalent on a crop sensor?
On APS-C (1.5x crop) it frames like 32mm on full frame, with a 59.5° horizontal and 69° diagonal field of view. These figures are calculated from the focal length and crop factor.
