Quick answer
The Vivitar 105mm f/2.5 Auto is a short telephoto prime lens covering 105mm at f/2.5 for the Pentax K mount. Its bright maximum aperture handles indoor and evening light reasonably well.
About this lens
The Vivitar 105mm f/2.5 Auto is a short-telephoto prime lens covering 105mm at f/2.5 for Pentax K mount cameras. The focal length is a classic choice for portraits and details.
Vivitar 105mm f/2.5 Auto specifications
What can you shoot with the Vivitar 105mm f/2.5 Auto?
At 105mm this is a short telephoto prime, which typically suits:
- Portraits with a flattering perspective
- Events and weddings
- Isolating subjects from the background
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 | 105mm | 19.5° | 23.3° |
| APS-C | 1.5x | 158mm | 13° | 15.6° |
Frequently asked questions
What mount does the Vivitar 105mm f/2.5 Auto use?
It uses the Pentax K mount, so it fits Pentax K cameras directly.
What is the focal length of the Vivitar 105mm f/2.5 Auto?
It is a fixed 105mm lens with a maximum aperture of f/2.5. That makes it a short telephoto lens.
Is the Vivitar 105mm f/2.5 Auto a prime or a zoom lens?
It is a prime lens with a fixed 105mm focal length. Primes usually open wider than zooms; this one opens to f/2.5.
What is the Vivitar 105mm f/2.5 Auto equivalent on a crop sensor?
On APS-C (1.5x crop) it frames like 158mm on full frame, with a 13° horizontal and 15.6° diagonal field of view. These figures are calculated from the focal length and crop factor.
Which cameras does the Vivitar 105mm f/2.5 Auto 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.
