Rokkor
camera lens
Rokkor was a brand name used for all Chiyoda Kōgaku Seikō and later Minolta lenses between 1940 and 1980, including a few which were marketed and sold by other companies like Leica. The name was derived from the name of Rokkō (六甲山), a 932 metres (3,058 ft) high mountain, which could be seen from the company's glass-making and optics factory at Mukogawa near Osaka, Japan. The company's founder Kazuo Tashima wanted the name to symbolize the high quality in optics.
Overview
The first lens to carry the Rokkor designation was a 200mm f/4.5 lens that came with the hand-holdable aerial camera Chiyoda SK-100 in 1940. After the Rokkor name was dropped and no longer engraved in new lenses after 1980/1981, the Rokkor name resurfaced two times. As was revealed not before 2006, the Rokkor name was still used internally for prototypes of a never released SR-mount Minolta MD Apo Tele Rokkor 300mm f/2.8 manual-focus lens in the early 1980s, a lens design, which later saw life as the A-mount Minolta AF Apo Tele 300mm f/2.8 G in 1985, a non-Rokkor auto-focus lens. The Rokkor name was also resurrected for a short time between 1996 and 1998 for the Minolta G-Rokkor 28mm f/3.5 lens. As the only officially released auto-focus Rokkor ever, this lens was incorporated into the Minolta TC-1 135 film compact camera. To celebrate Minolta's 70th anniversary in 1998, the same optics were also used in the Minolta TC-1 Limited as well as in a Leica thread-mount version of the lens in a limited production run of 2000 units for the Japanese market only.
When the brand was still used by Minolta, there were also printed Minolta magazines named "ROKKOR" in Austria and Japan.
Begin with the source’s own compact description: “Rokkor” is camera lens. The dossier treats that line as a proposition to test through Rokkor, camera and lens, not as a finished interpretation.
Why this record matters
The phrase “camera lens” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Dec 18, 2025. The linked authority identifier is Q1367613. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1940, 1980, 1981 and 2006.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Rokkor”, its source revision and the description used here.
- Expand the search: follow Rokkor primary sources, Rokkor archive and Rokkor research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Rokkor”?
- Which institution is responsible for the underlying evidence?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “Rokkor” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.