Auto Rikenon 300mm f/5.5

Ricoh · M42 · 1967

our own finding

Also known as: Auto Rikenon 300mm f/5.5 · Auto Rikenon 300mm f5.5 · Auto Rikenon 300mm · Auto Rikenon 1:5.5 f=300mm · Auto Rikenon 1:5.5 300mm · Rikenon Auto 300mm · Ricoh Auto Rikenon 300mm · Ricoh Rikenon 300mm f5.5 · Rikenon 300mm f/5.5 · Rikenon 300mm f5.5 · Rikenon 300mm 1:5.5 · Rikenon 1:5.5 f=300mm · Rikenon f=300mm 1:5.5 · Rikenon 5.5/300 · Rikenon 300mm M42 · Auto Rikenon 1 5.5 f300mm · Auto Sears 300mm f/5.5 · Sears 300mm f/5.5 · Sears 300mm f5.5 · Rikenon 5,5/300 · Rikenon 300 mm f/5.5 · Auto Sears 1:5.5 f=300mm · Rikenon 1:5.5 300mm

Variants & identification

Variant	Mount	Years	Serial ranges	Production
Auto Rikenon 300mm f/5.5	M42	—	—	—
Auto Sears 300mm f/5.5	M42	—	—	—

Construction (3 groups, 5 elements), closest focus (6.0 m), angle of view (8°) and filter (62 mm) are from Ricoh's tables in the SLX 500 and Auto TLS EE instruction books, which agree. Weight differs: 850 g (1.87 lb) in the Auto TLS EE book and in Dr. Ricoh's list, 840 g (1.85 lb) in the SLX 500 book. The f/22 smallest stop is from Dr. Ricoh's list and photographed examples. No source gives the number of diaphragm blades, the length or the diameter.
Dates: no source dates the lens. 1967 on this page is the year Ricoh gives for the Singlex TLS, the earliest body whose instruction book lists a '300mm f 5.5 automatic'. The book is undated and could be a later printing, so the lens may be somewhat younger than the camera. It is still in the SLX 500 (1975) and Auto TLS EE tables. Ricoh dates the Auto TLS EE to 1976; camera-wiki cites a July 1973 Popular Photography advertisement introducing it in the US, so the lens was current in either 1973 or 1976 at the latest, depending on which date is right. No end date was found; Ricoh moved to the Pentax K mount with the XR-1 and XR-2 in 1977.
A preset RIKENON 1:5.5 f=300mm with no 'Auto' on the front ring also turns up: two photographed examples (serials 10150 and 10361, one with a JCII PASSED sticker and a case with the Ricoh logo) have a preset ring and an aperture ring, both running 5.5 to 32, a tripod collar and a pull-out hood. Its mount is not established: one seller calls it M42, the other says the mount is unknown, and the photographs do not settle it. Dr. Ricoh lists a 5.5/300, named without 'Auto' and with no specification, for the Nikon F-mount Ricoh Singlex of 1962. These may be the same lens, but no source says so. It is not given a variant here until a document or a clear photograph of the mount places it.
The Auto Sears variant rests on one photographed example matched to the Ricoh lens by its barrel and controls; that identification is this page's own and is flagged as original research.

How to tell them apart (expand)

Engraved 1:5.5 f=300mm on the front ring; the Ricoh lens reads AUTO RIKENON, the Sears one AUTO SEARS
Long black barrel with a rotating tripod collar and locking knob, a built-in pull-out hood and a 62 mm filter thread
Aperture ring 5.5–22 plus an M/A ring for automatic or manual diaphragm. A lens with two aperture rings running to 32 is the preset Rikenon 300mm, not this one
Ricoh's later K-mount 300mm, the XR Rikenon APO 300mm f/4.5, is a different lens: f/4.5, APO on the barrel, 67 mm filter, Pentax K bayonet

Auto Rikenon 300mm f/5.5:

Front ring engraved AUTO RIKENON 1:5.5 f=300mm with a five-digit serial and LENS MADE IN JAPAN (examples photographed in listings read 11020 and 11084)
Single aperture ring from 5.5 to 22, with a separate M/A ring behind it for automatic or manual (stop-down) diaphragm operation
Rotating tripod collar with a locking knob, a long ribbed focusing ring scaled to 6 m / 20 ft, and a built-in pull-out lens hood
Ricoh's tables: 3 groups, 5 elements, 6.0 m closest focus, 8° angle of view, 62 mm filter, 850 g in the Auto TLS EE book (840 g in the SLX 500 book)

Auto Sears 300mm f/5.5:

Front ring engraved AUTO SEARS 1:5.5 f=300mm with a five-digit serial (10824 on the example photographed) and LENS MADE IN JAPAN
Otherwise the same barrel as the Auto Rikenon in listing photographs: 5.5–22 aperture ring with M/A ring behind it, rotating tripod collar with locking knob, ribbed focusing ring, built-in pull-out hood

Auto Rikenon 300mm f/5.5: The automatic-diaphragm 300mm of Ricoh's M42 line. The Singlex TLS instruction book lists a '300mm f 5.5 automatic' among the accessory Rikenon lenses, and the later SLX 500 and Auto TLS EE books give its full specification in their lens tables. It is an ordinary stop-down M42 lens: there was never an EE version, so on the Auto TLS EE it gives no shutter-priority automation and is metered by hand or stopped down. Dr. Ricoh's list gives f/22 as the smallest stop, which matches the aperture ring on photographed examples. No source dates its introduction or end, gives a price, or names the maker of the optics.
Auto Sears 300mm f/5.5: Sears sold Ricoh's M42 bodies and lenses under its own name (the Sears TLS is a Singlex TLS), and this lens is the 300mm of that line. No Sears or Ricoh document names a Sears 300mm, so the identification rests on the photographed example: engraving layout, controls, collar and hood all match the Ricoh lens. Sears bought lenses from more than one Japanese maker, so a Sears 300mm f/5.5 without the M/A ring and tripod collar described here is not necessarily this lens. One collector on the MFLenses forum (2008) describes an Auto-Sears 300/5.5 sold with small variations as Vivitar, Soligor, Lentar and Mamiya and believes it was made by Tokina; he does not say whether it is the same lens as the Ricoh one, and no source settles which Sears 300mm f/5.5 is which.

Serial-range notes

Five-digit serials, 10xxx–11xxx: Serials seen in listing photographs: 11020 and 11084 on Auto Rikenon lenses, 10824 on an Auto Sears lens, and 10150 and 10361 on the preset Rikenon 300mm f/5.5 described in the table notes. Five examples are too few to say whether Ricoh numbered the versions in one sequence or what the ranges mean.

Specifications

Construction: 5 elements / 3 groups
Aperture range: f/5.5–f/22
Min. focus: 6 m
Weight: 850 g
Filter: 62 mm

What reviewers say

No reviews aggregated yet — this family is still in the research queue. Written one? We'd love to index it.

Optical formula

No cross-section found: Ricoh's instruction-book tables give only the 3-group, 5-element count, and Dr. Ricoh's list adds nothing on the layout.

History

The Auto Rikenon 300mm f/5.5 is the long telephoto of Ricoh’s M42 screw-mount system: the longest of the automatic-diaphragm primes after the 400mm f/6.3, and shorter than the 500mm f/8 and the preset 600 and 800mm lenses. It is a slow, fairly simple lens: Ricoh’s own tables, in the SLX 500 and Auto TLS EE instruction books, give 5 elements in 3 groups, focus to 6 m, an 8° angle of view and a 62 mm filter. They disagree slightly on weight, 840 g in the SLX 500 book against 850 g in the Auto TLS EE book, which Dr. Ricoh’s list follows. The barrel carries a rotating tripod collar with a locking knob and a built-in pull-out hood, and the diaphragm is automatic, with an M/A ring behind the aperture ring for stop-down metering. No source dates it exactly, prices it or says who made the glass.

It has been in the system from early on. The instruction book for the Singlex TLS, the first M42 body in Ricoh’s own camera list (1967), already names a ‘300mm f 5.5 automatic’ among the accessory Rikenons. That book is undated, so this places the lens in the TLS era rather than in 1967 itself. The lens was still listed for the SLX 500 of 1975 and for the Auto TLS EE, which Ricoh dates to 1976 and camera-wiki, on the strength of a 1973 advertisement, to 1973. That makes it a period lens for every Ricoh M42 body: the Singlex TLS, the Ricohflex TLS 401, the SLX 500, the Singlex II and the Auto TLS EE. On all of them it works as an ordinary automatic-diaphragm M42 lens, metered stopped down or however the body meters. The Auto TLS EE book lists EE lenses only at 28, 35, 135 and 200mm, and Dr. Ricoh adds an EE 50mm f/1.7 standard lens; no source lists an EE 300mm. The 300mm has no EE setting, so on the Auto TLS EE it gives no shutter-priority automation and is used like any other M42 lens. Ricoh calls the Auto TLS EE the first AE camera on the M42 mount. As history that is wrong: Asahi’s aperture-priority Pentax ES of 1971 was an M42 automatic-exposure camera before it, whichever date is taken for the Ricoh.

Sears sold Ricoh’s Singlex TLS as the Sears TLS, and a photographed Auto Sears 300mm f/5.5 has the same engraving layout, M/A ring, tripod collar and hood as the Rikenon, so it appears to be this lens under a Sears badge. Not every Sears 300mm f/5.5 is: one collector on the MFLenses forum describes an Auto-Sears 300/5.5 that was also sold as a Vivitar, Soligor, Lentar and Mamiya and believes it to be a Tokina, so a Sears lens should be matched to the Ricoh one by its barrel, not its badge. Ricoh also made two other 300mm f/5.5 lenses, and they are easy to mix up. Dr. Ricoh lists a non-auto 5.5/300 for the Nikon F-mount Singlex of 1962. A preset lens engraved simply RIKENON 1:5.5 f=300mm, with a preset ring and an aperture ring running to f/32, also turns up in Ricoh-logo cases. Whether that preset lens is the Nikon F one, an M42 lens or something else is not settled by any source, so it is not treated as a version here. The K-mount XR Rikenon APO 300mm f/4.5 that came in the 1980s is a separate, larger design.

When buying, first read the front ring: AUTO RIKENON (or AUTO SEARS) with an aperture ring stopping at 22 is this lens, while a plain RIKENON with two rings to 32 is the preset one. On an automatic M42 body, check that the diaphragm snaps closed when the pin is pressed and with the M/A ring at A. Telephotos of this age often have a sluggish diaphragm and haze between the elements, and one German dealer’s listing of this lens says it has fungus. Also check that the tripod collar locks and the hood slides without dropping. At 6 m closest focus and f/5.5 it is a lens for distant subjects on a tripod, and nobody consulted has published a review of it. No period price and no photograph cleared for reproduction were found.

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This history is AI-written, from the sources listed at the foot of the page. Where the record is silent it says so rather than filling the gap — but no human wrote these sentences.

Example photos

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