Glass Bodies a variant-level encyclopedia of vintage lenses and cameras by iwillpat

Planar T* 50mm f/1.7 (C/Y)

Carl Zeiss · Contax/Yashica · 1979

Also known as: Contax Planar 50mm f/1.7 · Contax Carl Zeiss Planar T* 50mm F1.7 · Carl Zeiss Planar T* 50mm F1.7 C/Y · Planar T* 50mm F1.7 MMJ · Planar T* 50mm F1.7 AEJ · Planar 1,7/50 T* · Planar 1.7/50 C/Y · Contax Zeiss 50mm 1.7 · CONTAX Carl Zeiss Planar T* 50mm F1.7 MM · CONTAX Planar T*50mm F1.7 AE · コンタックス プラナー 50mm F1.7 · コンタックス Carl Zeiss Planar T* 50mm F1.7 MMJ · プラナー T* 50mm F1.7 AEJ

Variants & identification

Variant Mount Years Serial ranges Production
AE (Japan, 1979–85) Contax/Yashica 1979–1985 — —
MM (Japan, 1985–2005) Contax/Yashica 1985–2005 — —
  1. Construction (6 groups, 7 elements), 45°, 0.6 m closest focus, 190 g, 61 × 36.5 mm, 55 mm filter and the f/1.7–16 scale are Kyocera's figures from its product page for the MM lens (kyocera.co.jp, archived 2003, page copyright 2002). Japanese Wikipedia gives the same construction, closest focus and filter. Zeiss's historical data sheet gives about 195 g, the figure Phillip Reeve and Craig Marshall also quote; Reeve measures 36 mm long and 59 mm across against Kyocera's 36.5 × 61 mm. The table carries Kyocera's numbers.
  2. Blade count: six, counted by Phillip Reeve on his AE copy; Kyocera's page does not give it.
  3. Price: ¥29,000 without case is Kyocera's list price for the MM lens as still sold in 2002–03, the only maker list price found; no 1979 launch price was found. Used around 2015: $120–140 on eBay.com, €65–100 on eBay.de (Reeve); $150–250 for a good copy in 2019 (Marshall).
  4. Dates: 1979 for the AE lens and 1985 for the MM barrel are Japanese Wikipedia's; 2005 is the end of Kyocera's Contax business, not a published discontinuation date.
  5. Origin: Japan for both generations (Japanese Wikipedia; Reeve's AE copy); no West German run is documented.
How to tell them apart (expand)
  • Name ring reads Carl Zeiss Planar 1,7/50 T*; 'Lens made in Japan'; 55 mm filter; the smallest and lightest C/Y standard lens at 190–195 g and 36.5 mm long
  • Plastic focus and aperture rings over a metal inner barrel, filter thread and mount, the one C/Y Zeiss prime so made; the f/1.4 is all metal with rubber grips
  • AE or MM: white 16 on the aperture ring is AE, green 16 is MM
  • Not to be confused with the Yashica ML 50mm f/1.7 or DSB 50mm f/1.9, which share the mount but carry Yashica's name, or with the Contax G Planar 45mm f/2 (autofocus, no focusing ring)

AE (Japan, 1979–85):

  • Minimum-aperture numeral 16 in white; no MM coupling cam
  • 'Lens made in Japan'; focus and aperture rings in plastic on a metal inner barrel, the one C/Y Zeiss lens so built (Reeve; Marshall)
  • The diaphragm does not show the saw-tooth opening of the f/1.4 AE lens (owner's note on an AEJ copy, FredMiranda thread)

MM (Japan, 1985–2005):

  • Minimum-aperture numeral 16 in green; extra MM cam on the mount for program and shutter-priority bodies
  • 'Lens made in Japan'

Specifications

Formula
Planar double-Gauss, 7 elements in 6 groups; 45° angle of view
Construction
7 elements / 6 groups
Aperture range
f/1.7–f/16
Diaphragm blades
6
Min. focus
0.6 m
Dimensions
61 × 36.5 mm
Weight
190 g
Filter
55 mm
Years manufactured
1979–2005
Country
Japan
Coating
Zeiss T* multicoating
Original price
¥29,000 without case, Kyocera's list price for the MM lens still on sale in 2002–03; no 1979 launch price was found (today ¥33,000)

What reviewers say

Optical Ratings

Aggregated from the reviews above — follow the links for the full picture.

Chromatic aberration
axial at f/1.7
Spherical aberration
low contrast open
Vignetting
2.1 stops open
Flare & ghosting
exceptional for era
Distortion
mild barrel

History

The Planar T* 50mm f/1.7 joined the Contax/Yashica line in 1979 as the cheaper standard lens, four years after the f/1.4 with which the RTS had been launched. It is a seven-element, six-group double-Gauss covering 45°, which Kyocera’s page points out is an unusually elaborate construction for a lens of this speed and price; it focuses to 0.6 m, half a stop slower and a little less close than the f/1.4, takes the same 55 mm filter, and at 190 g by Kyocera’s figure (195 g by Zeiss’s data sheet) and 36.5 mm long it is the smallest and lightest standard lens of the system. Both barrels were made in Japan; no West German run is documented. The AE lens ran from 1979 to 1985 and the MM lens, with the same optics, from 1985 until Kyocera’s Contax business closed; Kyocera was still listing it in 2002–03 at ¥29,000 without case, under a page heading that misprints the name as Distagon.

The barrel is where the lens shows its price. The inner barrel, filter thread and mount are metal, but the focus and aperture rings are plastic, and Phillip Reeve finds them poorly damped and the lens “a little cheap” in the hand; Craig Marshall calls it the one Contax lens with plastic components. The f/16 numeral colour and the MM cam separate the generations as on every C/Y lens: white 16 is AE, green 16 is MM. An owner’s note on an AEJ copy records that its diaphragm does not show the saw-tooth opening seen on the f/1.4 AE lens.

Optically the two 50s are close. Reeve’s test on a Sony A7 found the f/1.7 a little sharper than the f/1.4 at full aperture, with good resolution but low contrast at f/1.7, an excellent centre by f/2.8 and almost the whole frame excellent by f/5.6; vignetting of about 2.1 stops wide open, mild barrel distortion, no lateral colour but strong axial colour at f/1.7, and flare resistance he calls exceptional for its era. The out-of-focus rendering is harsh wide open and smooth by f/2.8, after which the six-blade aperture shape intrudes. His verdict is a versatile lens that “really shines from f/2.8”, with a price-to-performance ratio good but no longer exceptional at $120–140 around 2015. Marshall, writing for video use in 2019, found it the better of the two Contax 50s at full aperture, with minimal breathing and an iris that can be de-clicked, at $150–250 for a good copy.

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This history is AI-written, from the sources listed at the foot of the page. Where the record is silent it says so rather than filling the gap — but no human wrote these sentences.

Example photos

Sample photo wanted — shot with a Planar T* 50mm f/1.7 (C/Y)? We'd love to feature it (with credit).

Live listings

Asking price, DKK: a median of DKK 1,300 across 6 fixed-price listings on 2026-11-02 (middle half DKK 1,300–DKK 1,400). First day tracked.

Asking prices from the listings scanned, not sales; junk-flagged rows and auction lots excluded; other currencies are not converted.

Buying from Yahoo! Auctions outside Japan. It is a domestic marketplace: sellers ship within Japan, and most will not register an overseas buyer. A proxy service bids on your behalf, receives the item and forwards it, for a fee and a wait. Buyee, Jauce and ZenMarket each accept a Yahoo auction number directly. Listed alphabetically for information — none is recommended over another, and none of these is an affiliate link.

Listings updated 2026-11-02. Links go to the shop or marketplace that carries the item.

Related: Planar T* 50mm f/1.4 (C/Y) · Planar T* 55mm f/1.2 '100 Jahre Planar' (C/Y) · Makro-Planar T* 60mm f/2.8 (C/Y)

Sources (7)

Every page here is assembled from public sources, and the gaps are real ones. If you own this lens, know a serial number I'm missing, or can see where I have it wrong, tell me — corrections, serials and sample photos are all worth having.