Topcon IC-1 Auto

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The Topcon IC-1 Auto is a 1973-1978 35mm SLR from Tokyo Kogaku named for the Integrated Circuit which controlled its shutter priority auto exposure. It was the successor to the Topcon Unirex, and the last Topcon camera to use the UV bayonet lens mount. The IC-1 is remarkably similar to the Unirex in looks: rumour has it that Seikosha ceased to make the leaf shutter used in the Unirex, resulting in that camera being modified to accommodate a focal-plane shutter, and becoming the IC-1.

There are two versions of this camera, where the original dates from 1974 to 1976 and the new from 1976 to 1978. The difference between the two is mostly to do with the specification of the standard lens, where the original was a 50mm f2, and the new a 55mm f1.8. Accordingly the lens speed compensator dial on the original has a maximum setting of f2, while the new has a maximum of f1.8. Additionally, an LED battery condition indicator was added to the upper area of the viewfinder, it got a hot shoe flash connection, the Auto logo colour was changed from black to red, and the serial number was moved from the top plate (next to the rewind knob) to the back of the hot shoe mounting.

Specifications common to both versions:

  • Lens mount: Topcon UV bayonet. The mount included a locking facility when Topcor UV lenses are attached.
  • Viewfinder: Fixed eye-level Pentaprism finder, with 0.8x image (standard lens) and 93% of the width and length of the actual picture area. Micro-prism focusing spot surrounded by fine focus ring and full area ground-glass, with Fresnel lens plate. Aperture scale is visible on left edge of finder area, with warning areas at both ends of the scale.
  • Shutter: Electronically-controlled cloth focal plane shutter, with shutter speed ring on lens mount. Ten shutter speed settings (green: manual only) 1, 1/2, 1/4, (black: auto) 1/8, 1/15, 1/30, (flash sync: red) 1/60, 1/125, 1/250 and 1/500 second, plus Bulb. Internally coupled to the built-in exposure setting system.
  • Meter: TTL centre weighted full aperture measuring system, with two CdS cells on both sides of the finder eyepiece measuring the reflected light of the full finder area.
  • Exposure: Automatic shutter speed priority (1/8th to 1/500th), or fully manual.
  • Film Speed: 25 to 3200 ASA (plus DIN scale).
  • Flash: Electronic flash units sync at 1/60th.
  • Film Advance: Single stroke lever (120°).
  • Frame Counter: Automatic count-up and reset.
  • Rewind: Via crank and bottom release button.
  • Size: 141 x 93 x 59mm (W x H x D).
  • Battery: 2 x 1.35v PX625A mercury battery (use the equivalent WeinCELL MRB625 zinc air cell).