Category Archives: Pentax K-mount

Guest Review: Pentax SMC FA 31mm f1.8 Limited

11/15/2020:  “Alternatives” and “Conclusion” and “Notes” sections has been updated in light of new releases, and a few more sample images have been added.

The Pentax 31mm f1.8 Limited is a fast moderate wide angle lens released in 2001. It’s designated as one of Pentax’s “Limited” series, denoting its high status within the Pentax catalogue. Since its release, the 31 Ltd has been beloved, especially within the Pentax community. I picked up my first copy in pursuit of a fast, decently priced alternative to the Sony RX1. Sony hasn’t provided shooters with a native fast 35mm f1.8 or f2 option. The 31 Ltd was a highly praised lens upon release, but optics have come along way recently, and it’s getting long in the tooth. Let’s see how it holds up 17 years after it’s release, and what type of images we can expect.

The 31mm focal length is an oddity, being near but noticeably different from the more conventional 28mm or 35mm focal lengths. The 31 ltd functions as versatile jack-of-trades lens with its 31 FL. The lens is still in production by Pentax/Ricoh, coming in either silver or black.

To view larger versions of the photos in this review, follow this link to my Pentax 31 ltd album on flickr


Continue reading Guest Review: Pentax SMC FA 31mm f1.8 Limited

135mm legacy Shoot out: SMC Pentax-M f/3.5 vs Canon nFD f/3.5 vs. Panagor f/2.8

Shoot out: SMC Pentax-M 135mm f/3.5 vs. Canon nFD 135mm f/3.5 vs. Panagor PMC auto tele 135mm f/2.8

In my search for a compact but good budget telelens I came across the SMC Pentax-M 135mm f3.5 and the Canon newFD 135mm f/3.5. Later, I also found a Panagor PMC auto tele 135mm f/2.8 in Canon FD mount. These lenses are cheap, light, and small, but how do they perform?

Disclaimer: I only tested one sample of the Canon and Panagor, and two samples of the Pentax. Since these lenses are old there might be more sample variation than usual, other samples might perform slightly better or worse. Both Pentax samples displayed similar performance. 

Left to right: Panagor, Canon, Pentax


Specifications Canon newFD 135mm f/3.5 SMC Pentax-M 135mm f/3.5 Panagor PMC auto tele 135mm f/2.8 (FD)
Diameter 63 mm 63 mm 61 mm
Length 85 mm 66 mm 88 mm
Filter diameter 52 mm 49 mm 55 mm
Weight (ex. Adapter) 325 g 270 g 411 g
Aperture f/3.5-32 f/3.5-32 f/2.8-22
Minimal focus distance 1.3 m 1.5 m 1.5 m
Elements/groups 4/4 5/5 4/4*
Aperture blades 6 8 6

(*Based on the optical design of this lens for other mounts)
Continue reading 135mm legacy Shoot out: SMC Pentax-M f/3.5 vs Canon nFD f/3.5 vs. Panagor f/2.8