Auto Rikenon 400mm f/6.3 (M42)
Ricoh · M42 · 1967 · Four elements in three groups
Also known as: Auto Rikenon 400mm f6.3 · Auto Rikenon 400mm f/6.3 · Auto Rikenon 400mm 1:6.3 · Auto Rikenon 1:6.3 f=400mm · Ricoh Auto Rikenon 400mm f/6.3 · Ricoh Rikenon 400mm f6.3 · Rikenon 400mm f6.3 · Rikenon 400mm f/6.3 · Rikenon 400mm 1:6.3 · Rikenon 6.3/400 · Ricoh 400mm f6.3 M42 · Rikenon 6,3/400 · Rikenon 400 mm f/6.3 · オートリケノン 400mm F6.3 · リケノン 400mm F6.3 · Rikenon 1:6.3 400mm · Rikenon 1:6.3 f=400mm
Variants & identification
| Variant | Mount | Years | Serial ranges | Production |
|---|---|---|---|---|
| Auto Rikenon 400mm f/6.3 | M42 | — | — | — |
- The specifications are Ricoh's, from the lens table on p.14 of the Auto TLS EE instruction book: three groups, four elements, 8.0 m closest focus, 6° angle of view, 72 mm filter, 1,050 g (2.31 lb), automatic diaphragm. The SLX 500 instruction book's table (p.10) agrees on everything except the weight, which it gives as 1,045 g (2.30 lb); both figures are Ricoh's, and the header uses the Auto TLS EE book's 1,050 g. Dr. Ricoh's M42 table gives the same construction, focus distance and filter, and adds f/22 as the smallest aperture, which Ricoh's tables do not print. Dr. Ricoh's weight cell reads "1,05", which matches 1,050 g if read as kilograms. None of these sources gives a blade count, diameter or length.
- No launch or end date is known. The 1967 in the header is the year Ricoh gives for the Singlex TLS (June 1967), the first body whose instruction book lists the lens. That printing of the book is undated and also lists the 50mm f/1.7 and 70-230mm zoom, so it may be a later printing and the lens may be later than 1967. Dr. Ricoh's table gives no release date for it.
- Who made it is not recorded. Ricoh's books name no maker, and no source ties this lens to any other maker's 400mm f/6.3.
- No Sears-badged 400mm is on record. Sears sold other Rikenons as Auto Sears lenses, so a 400mm f/6.3 Auto Sears with a 72 mm filter and 8 m focusing would belong here if one turns up.
- No launch price is on record. Dr. Ricoh's list gives €40 in its Value (EUR) column, its estimated collector value for a copy in very good condition, not a recorded sale or a period price.
How to tell them apart
- Screw mount, 72 mm filter, 8 m closest focus: no other Ricoh M42 lens combines them
- Not to be confused with the Rikenon 6.3/400 that Dr. Ricoh lists in Nikon F mount for the 1962 Singlex; that lens has a bayonet, and no source compares the two optically
Auto Rikenon 400mm f/6.3:
- 72 mm filter thread, shared in Ricoh's table only with the Auto Rikenon 17mm f/4 and 21mm f/3.8; the Auto Rikenon 300mm f/5.5 takes 62 mm
- Closest focus 8.0 m, the longest of any automatic-diaphragm Rikenon in Ricoh's table (the 300mm focuses to 6.0 m)
- Automatic diaphragm, unlike the preset 600mm and 800mm Rikenons and the 500mm f/8, which Dr. Ricoh lists as a preset mirror lens
- No EE setting: Ricoh's list of Auto Rikenon EE lenses has no 400mm
- Auto Rikenon 400mm f/6.3: The longest automatic-diaphragm lens Ricoh offered for its screw-mount reflexes. It is listed as "400mm f6.3 automatic" among the accessory Rikenon lenses in the Singlex TLS and TLS 401 instruction books, and in the SLX 500 and Auto TLS EE books' lens tables among the ordinary Auto Rikenons, not among the four EE lenses. Dr. Ricoh's M42 table marks it as confirmed. The exact wording on the front ring is not recorded here.
Specifications
- Formula
- Four elements in three groups
- Construction
- 4 elements / 3 groups
- Aperture range
- f/6.3–f/22
- Min. focus
- 8 m
- Weight
- 1050 g
- Filter
- 72 mm
- Country
- Japan
What reviewers say
No reviews aggregated yet — this family is still in the research queue. Written one? We'd love to index it.
History
The Auto Rikenon 400mm f/6.3 was the longest lens with an automatic diaphragm that Ricoh sold for its M42 screw-mount reflexes. Beyond it the range went to the 500mm f/8, which Dr. Ricoh lists as a preset mirror lens, and to preset 600mm and 800mm lenses. Ricoh’s lens table in the Auto TLS EE instruction book gives the 400mm four elements in three groups, a 6° angle of view, a 72 mm filter, a closest focus of 8.0 m and a weight of 1,050 g; the SLX 500 book’s table matches it except for the weight, 1,045 g. The lens appears as “400mm f6.3 automatic” in the accessory-lens lists of the Singlex TLS and TLS 401 instruction books as well. No launch date has been found. The 1967 on this page is the year Ricoh gives for the Singlex TLS, the first body whose book lists the lens, and the undated TLS book that lists it may be a later printing.
It is an ordinary M42 lens with an automatic diaphragm and fits every Ricoh screw-mount body, as well as any other M42 camera. Ricoh’s camera list gives the Singlex TLS and TLS 401 through-the-lens stop-down metering, so the lens is metered at the taking aperture, and at f/6.3 and smaller that leaves a dim finder for the reading. The Auto TLS EE gives shutter-priority automation only with Ricoh’s EE lenses, and the EE list in its book stops at the 28, 35, 135 and 200mm. The same book offers a full-aperture metering mode for non-EE screw lenses, but only for lenses of f/5.6 or faster, so the f/6.3 400mm falls back on the camera’s stopped-down mode. The export SLX 500 and Singlex II of 1975–76 take it too. Ricoh’s camera list credits both with open-aperture metering, but the SLX 500’s own instruction book has the user press the preview lever, stopping the lens down, to take a reading. The Rikenon 6.3/400 that Dr. Ricoh lists for the Nikon F-mount Singlex of 1962 is a different mount. No source says whether it shares this lens’s optics. The later K-mount XR bodies need an adapter to take the screw-mount lens.
Little has been written about the lens beyond Ricoh’s own tables, and no review of it is on record. No source names its maker. When buying one, check for the screw mount, the 72 mm filter ring and the 8 m end of the distance scale. A lens of this weight hanging from a 42 mm thread puts strain on the mount, so support the lens when it is on a body; none of the sources says whether Ricoh fitted a tripod collar. As with any long lens of this age, check the front group for haze and fungus, make sure the focusing travel is smooth over its full length, and press the auto pin to confirm that the diaphragm closes promptly. No Sears-badged version has been found.
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
Sample photo wanted — shot with a Auto Rikenon 400mm f/6.3 (M42)? We'd love to feature it (with credit).
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