Photo: Rich Niewiroski Jr. (CC BY 2.5)
Quick answer
The Sigma 8mm f/3.5 EX DG Circular Fisheye is a ultra-wide fisheye lens covering 8mm at f/3.5 for the Pentax K mount. Its moderate maximum aperture works best in good light or with a higher ISO.
About this lens
A 8mm f/3.5 full-frame fisheye lens, the Sigma 8mm f/3.5 EX DG Circular Fisheye is designed for Pentax K mount bodies. It suits dramatic perspectives, astrophotography and creative wide-field work.
Sigma 8mm f/3.5 EX DG Circular Fisheye specifications
- Brand
- Sigma
- Mount
- Pentax K
- Focal length
- 8mm
- Maximum aperture
- f/3.5
- Lens type
- Fisheye
- Format coverage
- full-frame
- Optical construction
- 11 elements in 6 groups
- Aperture blades
- 6
- Minimum focus distance
- 0.14 m
- Maximum magnification
- 0.22x
- Weight
- 400 g
- Length
- 68.6 mm
- Diameter
- 73.5 mm
Specification source: sigmaphoto.com
What can you shoot with the Sigma 8mm f/3.5 EX DG Circular Fisheye?
At 8mm this is a ultra-wide fisheye, which typically suits:
- Landscapes and big skies
- Architecture and interiors
- Astrophotography and night skies
Its moderate maximum aperture works best in good light or with a higher ISO.
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 | 8mm | 132.1° | 139.4° |
| APS-C | 1.5x | 12mm | 112.6° | 122° |
Frequently asked questions
What mount does the Sigma 8mm f/3.5 EX DG Circular Fisheye use?
It uses the Pentax K mount, so it fits Pentax K cameras directly.
What is the focal length of the Sigma 8mm f/3.5 EX DG Circular Fisheye?
It is a fixed 8mm lens with a maximum aperture of f/3.5. That makes it a ultra-wide lens.
Is the Sigma 8mm f/3.5 EX DG Circular Fisheye a prime or a zoom lens?
It is a prime lens with a fixed 8mm focal length. Primes usually open wider than zooms; this one opens to f/3.5.
What is the Sigma 8mm f/3.5 EX DG Circular Fisheye equivalent on a crop sensor?
On APS-C (1.5x crop) it frames like 12mm on full frame, with a 112.6° horizontal and 122° diagonal field of view. These figures are calculated from the focal length and crop factor.
Which cameras does the Sigma 8mm f/3.5 EX DG Circular Fisheye fit?
Any Pentax K-mount camera, including Pentax K-1, Pentax K-3, Pentax K-3 II, Pentax K-3 Mark III, and Pentax K-30 and 15 more.
Alternatives for Pentax K from other brands
All Pentax K lensesSame mount, overlapping focal range, closest maximum aperture first.
