Rikenon Rikenon 135mm f2.8 Heritage

Overview

The Rikenon 135mm f/2.8 was produced by Ricoh, a Japanese manufacturer known for its XR Rikenon line of lenses. The reviews cover two closely related variants: the M42 screw-mount 'Auto Rikenon 135mm f/2.8' (featuring a ring-type A/M aperture switch and a 14mm retractable hood, with 6 aperture blades) and the later Pentax K-mount 'XR Rikenon 135mm f/2.8' (with 8 straight-edged blades, a built-in slide-out metal hood, and no Ricoh pin or A setting). A 1980 Ricoh brochure described the 135mm f/2.8 as 'quite possibly the most popular choice after the standard lens,' positioning it as an ideal, compact, and bright option for portraits, indoor and outdoor sports, landscapes, and other long-distance subjects. The lens is characterized by all-metal construction with a diamond-pattern rubber focusing ring on the K-mount version. No established nicknames or community jargon are evidenced in these reviews. Its modest cult appeal stems from being an underrated performer with excellent build quality at a very low price, with one reviewer on a Pentax K-1 calling it 'underrated' and noting it 'performs very well across the board.'

Verdict: The Rikenon 135mm f/2.8 is an underrated, superbly built budget telephoto that delivers strong, consistent sharpness and pleasing bokeh for very little money. Its only real quirk is a slightly cool rendering versus Pentax SMC glass, which is trivially fixed when shooting raw. Ideal for photographers wanting an affordable, well-made manual-focus 135mm for portraits, sports, and landscapes — with the M42 (Auto) version offering broad adaptability across mirrorless systems.

Optical Character

Bokeh

Rated well by reviewers, with a bokeh score of 9 from one reviewer and community averages around 7.0 and 4.33/5.

Color

Renders slightly cool compared to Pentax SMC lenses, easily corrected in raw.

Sharpness wide open

Highly rated for sharpness (community average 8.7; one reviewer gave a 9), performing very well across the board.

Community Insights

What people love

Excellent, all-metal build quality — one reviewer rated handling a perfect 10 and called the construction excellent
Strong, consistent all-around performance without notable weak points, described as 'underrated'
Well-controlled and easy-to-manage aberrations
Outstanding value at a very low average price (around $30–$35)
Good bokeh and high sharpness for the money

What people dislike

Slightly cool color rendering compared to Pentax SMC lenses (though considered a non-issue when shooting raw on digital)
Does not reach 'excellent' in any optical category, only in handling and build

Pro Tips

Shoot raw on digital to neutralize the lens's slightly cool color cast, as recommended by a Pentax K-1 user
Use it as a portrait, sports, and landscape telephoto — the role Ricoh's 1980 brochure designed it for
Leverage the long ~230° focus throw (K-mount version) for precise manual focusing

Sources (1)

Web-grounded synthesissecondary

The Rikenon 135mm f/2.8 was produced by Ricoh, a Japanese manufacturer known for its XR Rikenon line of lenses. The reviews cover two closely related variants: the M42 screw-mount 'Auto Rikenon 135mm f/2.8' (featuring a ring-type A/M aperture switch and a 14mm retractable hood, with 6 aperture blades) and the later Pentax K-mount 'XR Rikenon 135mm f/2.8' (with 8 straight-edged blades, a built-in slide-out metal hood, and no Ricoh pin or A setting). A 1980 Ricoh brochure described the 135mm f/2.8 as 'quite possibly the most popular choice after the standard lens,' positioning it as an ideal, compact, and bright option for portraits, indoor and outdoor sports, landscapes, and other long-distance subjects. The lens is characterized by all-metal construction with a diamond-pattern rubber focusing ring on the K-mount version. No established nicknames or community jargon are evidenced in these reviews. Its modest cult appeal stems from being an underrated performer with excellent build quality at a very low price, with one reviewer on a Pentax K-1 calling it 'underrated' and noting it 'performs very well across the board.'

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