The Eight-Element Legend
Every mount family keeps one legend, and the M42 file's is not an exotic. It is a standard 50 that looks, from a pace away, identical to its own replacement. Asahi's Super Takumar 50mm f/1.4 exists in two constructions: an eight-element version built from about 1964 to roughly 1966, and the seven-element recalculation that quietly took over its name, its barrel and its spot in the catalog, and ran on through the Super-Multi-Coated era. Same engraving on the front, same mount, same aperture ring under the thumb, one element of difference inside, and the hobby now pays a multiple for the early one. This file is about where the legend came from, why the company walked away from it without a word, and how to tell the two lenses apart without believing a single listing title.
The Planar problem
The story starts in Oberkochen. Zeiss shipped its Planar 50mm f/1.4 in 1963 and set the bar for fast standard lenses, and the Japanese makers set out to clear it. Asahi's answer arrived in 1964, and the optical department got there by spending: eight elements where the class standard was seven, a construction expensive enough that the hobby's standard account says the company lost money on every copy sold. The press reviews were the kind optics engineers frame, and the lens picked up the nickname the file records with the usual caution about nicknames: the Zeiss killer. The register cannot audit Asahi's unit economics sixty years later, so the losing-money story stays filed as the hobby's account rather than the company's. What is beyond dispute is what happened next.
The quiet retreat
Within roughly two years, the eight-element design was gone. Asahi recalculated the lens to seven elements using the new high-index glass of the era, thorium-doped, kept the name, the barrel style and the price position, and said nothing. The references put the handover around 1965 to 1967 and do not agree on the year, which this file records as a corridor in the house manner rather than picking a side. No announcement, no version number, no mark on the box. A great lens was replaced inside its own skin, and the only record of the change is the lens itself, which is the purest version of this register's founding situation: when the maker keeps no public record, the object is the record.
The radioactive irony
Here is the detail that connects this file to the thorium dossier: the legend is the version without the hot glass, mostly. The seven-element Takumar and its Super-Multi-Coated descendants carry thoriated elements, yellow with age in the familiar way, and sit on every radioactive-lens list ever compiled. The eight-element is conventionally described as thorium-free, and the file adds the honest asterisk: owners with meters have reported weak readings on some early copies, so the clean split the hobby repeats has measured exceptions on record. The practical doctrine survives the asterisk. Deep tea-colored yellowing is seven-element behavior, the thorium signature that doubles as a dating tool, while the eight-element runs cooler, its warmth coming from coatings rather than decay. A heavily yellowed lens being sold as an eight-element is making two claims that argue with each other.
The examination
Now the part the premium depends on, because the two lenses share a name and the listings know it. The tells, in the order of how well the references agree on them. First, the engraving narrows the field: Super-Takumar on the nameplate rules out the SMC generations, leaving the two claimants. Second, the aperture ring: the eight-element engraves the numeral 2 at f/2 where the seven-element generally wears a dot. Third, the stop-down switch: A and M on the eight-element, AUTO and MAN on the seven, and the hobby's teardown literature adds the stamped product codes, 35800 on the eight-element's hardware against 37800-series on the later lenses. Fourth, the rear element: focused to infinity, the eight-element's rear glass bulges noticeably toward the camera, enough that the file carries a warning about mirror clearance on some SLR bodies, while the seven-element sits flat. And fifth, the famous one, printed here with its dispute attached: the infrared focus index near the 4 on the depth scale. The references state this tell in opposite directions, one putting the eight-element's mark before the 4 and another after it, so this file ranks the hobby's best-known tell dead last and records both versions. Serial ranges overlap at the boundary and settle nothing alone. The doctrine is the same one the register applies everywhere: no single tell convicts or acquits, and an identification is the agreement of several, checked against a claimed year that must itself survive the family file.
What the premium is actually for
Strip the mythology and the eight-element premium is an identification premium: a multiple paid for one element nobody can see, attached to a lens the maker replaced without announcement, distinguishable only by reading the object the way this site reads everything. That is why the legend belongs to this register. A listing title that says eight-element is a claim; the numeral at f/2, the A-M switch, the bulging rear glass and the parts codes are the audit; and the asking price is only as real as the examination behind it. The company that built the best fifty of its era and then quietly stopped left collectors exactly one way to know what they are holding. Look at the lens. The lens is the record.