Cosinon-W 28mm 1:2.8

28mm
f/2.8
Prime

Quick answer

The Cosina Cosinon-W 28mm 1:2.8 is a wide-angle prime lens covering 28mm at f/2.8 for the Pentax K mount. Its bright maximum aperture handles indoor and evening light reasonably well.

About this lens

The Cosina Cosinon-W 28mm 1:2.8 is a wide-angle prime lens covering 28mm at f/2.8 for Pentax K mount cameras. The wide view suits landscapes, architecture and environmental shots.

Cosina Cosinon-W 28mm 1:2.8 specifications

Brand: Cosina
Mount: Pentax K
Focal length: 28mm
Maximum aperture: f/2.8
Lens type: Prime

What can you shoot with the Cosina Cosinon-W 28mm 1:2.8?

At 28mm this is a wide-angle prime, which typically suits:

Landscapes and cityscapes
Street and travel photography
Environmental portraits and interiors

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	28mm	65.5°	75.4°
APS-C	1.5x	42mm	46.4°	54.5°

Try the field-of-view calculator

Frequently asked questions

What mount does the Cosina Cosinon-W 28mm 1:2.8 use?

It uses the Pentax K mount, so it fits Pentax K cameras directly.

What is the focal length of the Cosina Cosinon-W 28mm 1:2.8?

It is a fixed 28mm lens with a maximum aperture of f/2.8. That makes it a wide-angle lens.

Is the Cosina Cosinon-W 28mm 1:2.8 a prime or a zoom lens?

It is a prime lens with a fixed 28mm focal length. Primes usually open wider than zooms; this one opens to f/2.8.

What is the Cosina Cosinon-W 28mm 1:2.8 equivalent on a crop sensor?

On APS-C (1.5x 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.