Samyang Pentax K Prime

20mm f/1.8 ED AS UMC

20mm
f/1.8
Prime

Quick answer

The Samyang 20mm f/1.8 ED AS UMC is a ultra-wide prime lens covering 20mm at f/1.8 for the Pentax K mount. Its fast maximum aperture helps in dim light and gives good subject separation.

About this lens

This 20mm f/1.8 fast wide-angle prime lens from Samyang fits Pentax K mount cameras, with extra-low dispersion glass and aspherical elements. The wide view suits landscapes, architecture and environmental shots.

Samyang 20mm f/1.8 ED AS UMC specifications

Brand: Samyang
Mount: Pentax K
Focal length: 20mm
Maximum aperture: f/1.8
Lens type: Prime

What can you shoot with the Samyang 20mm f/1.8 ED AS UMC?

At 20mm this is a ultra-wide prime, which typically suits:

Landscapes and big skies
Architecture and interiors
Astrophotography and night skies

Its fast maximum aperture helps in dim light and gives good subject separation.

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	20mm	84°	94.5°
APS-C	1.5x	30mm	61.9°	71.6°

Try the field-of-view calculator

Frequently asked questions

What mount does the Samyang 20mm f/1.8 ED AS UMC use?

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

What is the focal length of the Samyang 20mm f/1.8 ED AS UMC?

It is a fixed 20mm lens with a maximum aperture of f/1.8. That makes it a ultra-wide lens.

Is the Samyang 20mm f/1.8 ED AS UMC a prime or a zoom lens?

It is a prime lens with a fixed 20mm focal length. Primes usually open wider than zooms; this one opens to f/1.8.

What is the Samyang 20mm f/1.8 ED AS UMC equivalent on a crop sensor?

On APS-C (1.5x crop) it frames like 30mm on full frame, with a 61.9° horizontal and 71.6° diagonal field of view. These figures are calculated from the focal length and crop factor.