Contax G mount Ultra-wide prime
Contax Zeiss 21mm f/2.8 Biogon T*
Quick answer
The Contax Zeiss 21mm f/2.8 Biogon T* is a ultra-wide prime lens covering 21mm at f/2.8 for the Contax G mount. Its bright maximum aperture handles indoor and evening light reasonably well.
- Full frame
- APS-C (32mm equiv.)
- Micro Four Thirds (42mm equiv.)
- Other systems via mount adapter
- Focal
- 21mm
- Aperture
- f/2.8–22
- Weight
- 200g
- Filter
- 55mm
- Min focus
- 0.5m
What 21mm sees
- Full frame crop 1.0×
- 91.7° 81.2° horizontal
- APS-C crop 1.5× → 32mm
- 69° 59.5° horizontal
- Micro Four Thirds crop 2.0× → 42mm
- 54.5° 46.4° horizontal
Diagonal angle of view. Frames drawn to scale at 21mm. Calculated from the focal length and crop factor (adapted mount, so sensor size depends on your camera), not measured.
Open the field-of-view calculatorContax Zeiss 21mm f/2.8 Biogon T* specifications
Optics
- Focal length
- 21mm
- Maximum aperture
- f/2.8
- Minimum aperture
- f/22
- Format coverage
- Full frame
- Optical construction
- 9 elements in 7 groups
Focus
- Minimum focus distance
- 0.5 m
Physical
- Filter thread
- 55 mm
- Weight
- 200 g
- Length
- 35 mm
- Diameter
- 59 mm
Specification source: en.wikipedia.org
What can you shoot with the Contax Zeiss 21mm f/2.8 Biogon T*?
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.
Frequently asked questions
What mount does the Contax Zeiss 21mm f/2.8 Biogon T* use?
It uses the Contax G mount, so it fits Contax G cameras directly and can be used on other systems through a mount adapter.
What is the focal length of the Contax Zeiss 21mm f/2.8 Biogon T*?
It is a fixed 21mm lens with a maximum aperture of f/2.8. That makes it a ultra-wide lens.
Is the Contax Zeiss 21mm f/2.8 Biogon T* 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 Contax Zeiss 21mm f/2.8 Biogon T* 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. On Micro Four Thirds (2x crop) it frames like 42mm on full frame, with a 46.4° horizontal and 54.5° diagonal field of view. These figures are calculated from the focal length and crop factor.