Distagon T* 45mm f/2.8 (Contax 645)

The Distagon T* 45mm f/2.8 was one of the six lenses Kyocera launched the Contax 645 with in 1999, and the system’s everyday wide angle. Carl Zeiss’s data sheet, catalogue number 10 49 44 and printed on 9 March 1999, describes a retrofocus design of nine elements in seven groups with internal focusing: 45.5 mm, 76° across the 41.5 × 56 mm frame, f/2.8 to f/32, focusing to 0.5 m, with a 72 mm filter thread, 80 × 99 mm and about 821 g. Zeiss compares its view to a 28 mm lens on a Contax 35 mm SLR, the same pairing the camera’s own angle-of-view chart makes, and offers it for landscapes, cities, travel and weddings, fast enough at f/2.8 for indoor wedding coverage. The sheet’s text promises very uniform illumination from corner to corner and remarkably low distortion. Its own curves show barrel distortion of about 2% towards the corners and, wide open, about a third of the centre’s light reaching the extreme corners, rising to about 60% by f/8. Zeiss designed it and it was built in Japan: the barrel reads “Lens made in Japan”. Jason Schneider wrote in 2006 that the 645 lenses were made by Kyocera with Zeiss technicians checking quality on site. German Wikipedia says Zeiss supplied the lenses, and collection-appareils that Zeiss designed them in Germany; neither describes German manufacture. A boxed copy sold in Japan in 2026 came with a German-language Prüfzertifikat card from Carl Zeiss Qualitätssicherung, Zeiss’s quality assurance, carrying its serial.

Like every autofocus lens in the system, it is electronic. Kyocera’s repair manual says there is no mechanical coupling between body, lens and film back. A CPU in the lens reads the aperture ring, drives the focus motor and an aperture stepping motor that moves in eighth-stop steps, and keeps the lens’s data in its own memory, and nine gold contacts in the bayonet connect it to the body. The barrel has no AF/MF switch, because the focus mode is set on the body. In single autofocus the focusing ring can be turned after the camera has locked focus, and in shutter priority the camera chooses the aperture wherever the ring is set. Whether the focus motor is ultrasonic is unsettled: Outdoor Photographer’s 1998 preview promised six ultrasonic autofocus lenses, Japanese Wikipedia and PRONEWS say every autofocus lens in the system has one, Kyocera’s US release presents the ultrasonic motor as a feature of the Tele-Apotessar 350mm, and the repair manual says only that the motor is in the lens. The dedicated hood is the GB-71. Shige’s hobby, a collector’s site that has reviewed most of the range on a Leica S, says the GB-72 of the 55 and 80 and the GB-B1 bellows hood also fit, though the GB-72, made for longer lenses, may vignette on 645 film; all three Auto Extension Tubes can be used. The Mutar 1.4x does not: Zeiss limits it to the 140, 210 and 350.

The bench test and the users describe the same lens: strong in the centre, weaker at the edges, softer wide open. Popular Photography tested it for its November 1999 issue, and Mamiya America reprinted the figures in 2001 to set its own AF 45mm f/2.8 against it. The centre was rated excellent at every stop to f/22, 50 lines/mm wide open rising to 78 at f/5.6, but the corners measured only 24 wide open and never more than 36. Mamiya’s lens matched it in the centre at most stops, fell behind at f/4 and f/11, and led in the corners wide open and from f/5.6 to f/22. Shige, using the lens on a Leica S, finds it slightly soft wide open and sharper stopped down, a character he likens mildly to an older lens. He calls it the soft one of the three wide Distagons, against the 35’s resolution, and rarely saw flare even without a hood. Hidekazu Tominaga, reviewing the camera for PRONEWS in 2024, called it an excellent lens but found the camera’s autofocus “quite questionable” with wide-angle shots and advised watching where it focuses. Shige rated autofocus speed on the Leica S as standard for the system. Fringer lists it, with every other autofocus lens in the range, under “better AF performance” on its Fujifilm GFX adapter, and GL Optics rehouses it as a T2.8 cine lens.

Camera World in Portland advertised it at $2,249 in May 2000, between the Planar 80’s $1,565 and the Distagon 35’s $2,395, and Shige gives ¥250,000 before tax as its yen list price. Shige now calls it the accessible way into the system: relatively affordable and often on the used market, from about ¥70,000 in 2023. Its prices spread widely. On Yahoo! Auctions in 2026 a boxed copy with dust but no fungus or haze, its diaphragm and autofocus working, made ¥190,804 after 27 bids on 4 October. A clean copy made ¥126,111 in June, a boxed copy with heavy spot fungus ¥100,208, and a copy with fungus sold with only its aperture checked ¥45,055. Kamerastore offered one with minor internal haze at US$1,005 in October 2026. Check any copy on a working Contax 645 body, since its diaphragm and focus move only under their own motors. Look for fungus and haze, and for corrosion on the contacts. Kyocera stopped accepting Contax repairs on 30 April 2015 and now refers owners to Repair Service Suwa. In 2026 one Yahoo! seller had a body, this lens and the Planar 80 inspected and repaired there before sale, and left the Sonnar 210 out because the work would have cost more than it was worth.

There is one version. No optical revision, finish or edition has turned up. Serials come in two forms, seven digits beginning 879 (8793447, 8794086, 8795092, 8796092) and eight digits (15026768), with no table to date either. Kamerastore’s copy, no. 8793447, carries a CE mark above “Lens made in Japan”; three higher-numbered copies do not, too few to say whether the mark follows serial, market or date. The namesakes are easy to tell apart. Mamiya’s AF and Sekor C 45mm f/2.8 lenses and Pentax’s A and FA 645 45mm f/2.8 carry their makers’ names and take 67 mm filters, or 77 mm on the first Sekor C. The Contax/Yashica Tessar 45mm f/2.8 is a 35 mm pancake, and the Contax G Planar 45mm is an f/2 rangefinder lens. A Distagon engraved 2,8/45 with gold contacts can only be this one.

Still open: a Kyocera list price in yen, any production figure or serial table, which Kyocera plant made the lens, the number of aperture blades, and whether the CE mark follows a market or a production period.