F-Distagon 24mm f/3.5 IHI (circular fisheye)

The 24mm F-Distagon was never a Hasselblad catalogue lens. It was a special order, built in 1984 in something between 50 and 100 examples, and it appears in none of the places a V-system lens normally appears: Hasselblad Historical’s lens index has no 24mm entry, and there is no Zeiss data sheet for it in the series that documents every other Distagon and Biogon on the mount. What confirms it exists is commerce — KEH has catalogued one as a “Hasselblad 24mm f/3.5 F-Distagon CF IHI Fisheye Lens for Hasselblad 500 Series V System”, Leitz Auction has sold a “Carl Zeiss f. Hasselblad F-Distagon 3.5/24mm” catalogued as a prototype, and a further sold listing headed “extremely rare Hasselblad IHI f/3.5 24mm circular fisheye” survives in an auction archive. Everything else here is second-hand, and should be read that way.

What makes it interesting is the picture it draws. The 30mm F-Distagon is a full-frame fisheye: 180° across the diagonal with the corners filled. The 24 is a circular fisheye, laying a disc of image inside the 56 mm square with black around it — Emulsive calls it “one of the only true circular fisheye lenses ever made” and puts the current price at around $25,000. Two forms are consistently described. One carries a Prontor CF shutter in a CF-style barrel and works on any V body; the other has no shutter at all, which restricts it to the focal-plane 2000- and 200-series cameras, and is usually reported with a yellow filter fitted. Emulsive splits the run roughly 50 shutterless to 30–50 shuttered out of 80–100 total; The Fish List reports 50 units as the figure known to it, while also citing the same 80–100 range.

The purpose is the part that most needs a caveat. The Fish List says the lens was “specially built for a rubber tire industry, quality control purposes, sampling pictures from inside the tire” — a plausible use for a lens that photographs a full hemisphere from inside a cavity, and consistent with the fixed yellow filter, but stated by one source and no other. The same page gives an angle of view of 300° on the 56 mm circle, which no lens achieves and no other source repeats; it is recorded here only so that a reader who meets the figure elsewhere knows where it comes from. The 9 elements in 7 groups quoted online carries no citation, and the weight of 1365 g is exactly the figure Zeiss’s data sheet gives for the CF 30mm fisheye, which is either coincidence or a number copied from the wrong row.

Nor does anything consulted say what IHI stands for. It is used as a bare designation on dealer and reference pages, and reads like the abbreviated name of the customer who ordered the lens, but no source consulted spells it out and this entry does not guess.

Open: what IHI is; who ordered the lenses and for what, beyond the single tyre-industry claim; the true production figure and split; the optical prescription, since no data sheet, patent or cross-section has been found; whether the shutterless form carries Hasselblad’s F designation or is simply a barrel without a shutter; what the engraving on the barrel actually says; whether any of this is documented in Nordin’s compendia; and whether the Leitz lot catalogued as a prototype is a pre-production example or the same lens described loosely.