Hasselblad (Ross) HK 7

The HK 7 exists because of a German camera that came down in Sweden. Hasselblad’s own history has the Swedish Air Force bringing Victor Hasselblad an intact aerial hand camera recovered on Swedish soil in 1940 and asking whether he could copy it; his reply, in the version Evald Karlsten recorded from him, was that he could not make one like it but could make one better. The Flygvapenmuseum’s collection notes identify what he had been handed — a German camera with a curtain shutter speeded 1/100, 1/200 and 1/500 — and camera-wiki names it as probably the Handkammer HK 12.5cm/7×9, which is where the Swedish camera’s 7×9cm format and its “HK” prefix come from. The workshop opened in April 1940 in a shed beside a car repair business in central Göteborg, under the name Ross AB, with a mechanic from that business and his brother as the first staff. Chernoff’s account on Hasselblad Historical, written with Richard Nordin, has one working camera by early 1941, at which point staff rose to about twenty and the operation moved into a proper factory building.

What Hasselblad changed is the substance of the design. In place of the German focal-plane curtain he fitted a leaf shutter behind the lens — four blades in a 40mm throat, made in the Ross shop itself, which Chernoff establishes from examined cameras and from factory photographs Nordin found of Ross craftsmen cutting shutter leaves. The Ross shutter runs 1/150, 1/250 and 1/400 only; a leaf shutter exposes the whole frame at once, so a fast-moving aircraft does not skew the image as it does through a travelling slit. Lenses were interchangeable through a three-lobed bayonet with one narrow lobe so the lens seats one way, all fixed at infinity and all uncoated: a Zeiss Biotessar 13.5cm f/2.8 as standard, with a Schneider Xenar 24cm f/4.5 and a Meyer Tele-Megor 25cm f/5.5 as telephotos. A Tessar 13.5cm f/4.5 appears on the auctioned no. 89 and is not in Chernoff’s list. Every barrel was hand-fitted and engraved with its body’s serial, and the same serial is stamped into the memo plate on the rear cover, whose red dot must meet the body’s — a fitting practice that Chernoff traces forward to the serial-stamped magazine inserts of the lettered 1600F in 1950.

The camera is large: 31cm long, 26cm across the wooden grips, 17.6cm high and 4.8kg with the standard lens, on Hasselblad Historical’s measurements, which Hasselblad’s history page repeats. A thumb lever in a turret on top advances the film and cocks the shutter, the right index finger fires it, and a folding wire frame finder gives two fields, the inner frame serving both telephotos. There is no dark slide and no interchangeable back — the rear cover simply slides off the casting — which is why Chernoff calls the 1951 company brochure wrong to say that all 342 wartime cameras had quickly interchangeable magazines; interchangeable backs arrived with the SKa 4 in 1942. Filters slide into a slot in the lens barrel against spring-loaded ball detents, and the lens cap comes off with one slide, in gloves.

How many were built depends on which figure is being counted. Hasselblad Historical and the company’s history page agree on 240 HK 7s, serials 1 to 240, between 1941 and 1943; the 342 that Hasselblad’s history also gives — and that Japanese Wikipedia repeats — is the brochure’s total for every camera Ross delivered to the Swedish forces in 1941–45. Chernoff’s own model-by-model sum comes to about 404 (240 HK 7, 70 SKa 4 and 4a, 70 MK 80, 24 SKa 5), so he treats 342 as unconfirmed rather than wrong. Surviving examples with known serials are few: no. 164 sold at Westlicht in November 2014 with a Tele-Megor 25cm, and no. 236 has passed through auction, both cited by camera-wiki.

Two things in the record do not agree and cannot yet be settled. The Westlicht description of no. 164 gives shutter speeds of 1/50, 1/100 and 1/250, against the 1/150–1/400 of the cameras Chernoff and Nordin handled; whether a late camera carried a different shutter or the catalogue simply erred is unknown. And the designer’s credit is thinner than it looks: Chernoff’s caption names Gustaf Andersson, later Tranefors, as the man who built the test shutter into the first body, and links Carl Gustaf Tranefors’s American patent 2,398,567 for the camera shutter, while Hasselblad’s history speaks only of an unnamed mechanic and his brother. No price is recorded — the camera was a military contract, never a catalogue item — and no source names the aircraft it flew in.