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

SMC Pentax-A / FA 645 75mm f/2.8

Pentax · Pentax 645 · 1984

Also known as: SMC Pentax-A 645 75mm f/2.8 · SMC Pentax-FA 645 75mm f/2.8 · smc PENTAX-A 645 75mm F2.8 · smc PENTAX-FA645 75mmF2.8 · Pentax 645 75mm f/2.8 · Pentax 645 75/2.8 · Pentax-A 645 75mm · Pentax FA 645 75mm · ペンタックス 645 75mm F2.8 · smc PENTAX-A 645 75mmF2.8

Variants & identification

Variant Mount Years Serial ranges Production
SMC Pentax-A 645 75mm f/2.8 (manual focus, 1984) Pentax 645 1984 — —
SMC Pentax-FA 645 75mm f/2.8 (autofocus, 1997) Pentax 645 1997 — —
  1. A-version figures are from the PentaxForums lens database and camera-wiki (which cites Popular Photography, June 1984); FA-version figures are from Ricoh Imaging's Japanese and US spec pages. The 25 g difference is barrel material, not glass: both versions are 6 elements in 5 groups.
  2. No launch price in yen or dollars was found for either version. The only list price seen is Ricoh Imaging USA's current $699.95 for the FA, which is not a launch figure and is not entered as one.
  3. A leaf-shutter smc PENTAX 645 LS 75mm f/2.8 also exists for flash sync; it is a separate lens and is not covered on this page.
How to tell them apart (expand)
  • A or FA after PENTAX on the front ring is the whole story: A is manual focus with a metal barrel, FA adds a screwdrive AF coupler and an AF/MF switch
  • Both versions: 58 mm filter, 37.5 mm long, f/2.8 to f/22, 0.6 m closest focus, 8 blades, A position on the aperture ring
  • Weigh it if the engraving is worn: 240 g is the A, 215 g the FA

SMC Pentax-A 645 75mm f/2.8 (manual focus, 1984):

  • Engraved smc PENTAX-A 645 1:2.8 75mm on the front ring; metal barrel; no AF/MF switch and no screwdrive coupler in the mount
  • Aperture ring with the green A position; 58 mm filter thread; RH-A 58 mm screw-in hood and S80-80 case were the listed accessories (PentaxForums)
  • 240 g and 74 × 37.5 mm (PentaxForums; camera-wiki, citing Popular Photography, June 1984)

SMC Pentax-FA 645 75mm f/2.8 (autofocus, 1997):

  • Engraved smc PENTAX-FA 645 1:2.8 75mm; AF/MF switch on the barrel and a screwdrive AF coupler in the mount; the focusing ring turns during autofocus (PentaxForums user reviews)
  • Lighter barrel with more plastic: 215 g against the A's 240 g, 74.5 × 37.5 mm (Ricoh Imaging spec page)
  • Same 58 mm filter, same RH-A58 hood (sold separately) and S80-80 case; product code 26121 (Ricoh Imaging; PentaxForums)

Specifications

Construction
6 elements / 5 groups
Aperture range
f/2.8–f/22
Diaphragm blades
8
Min. focus
0.6 m
Dimensions
74 × 37.5 mm
Weight
240 g
Filter
58 mm
Years manufactured
1984
Country
Japan
Coating
SMC (Super Multi Coating) on both versions

What reviewers say

History

The 75mm f/2.8 is the normal lens of the Pentax 645, sold with the body when the camera appeared at the 1984 PMA show and still the lens most 645s turn up with. Six elements in five groups, f/2.8 to f/22, 0.6 m closest focus, a 58 mm filter thread and a barrel only 37.5 mm long at 240 g: the figures come from the PentaxForums lens database and match camera-wiki’s table, which cites Popular Photography of June 1984. Japanese Wikipedia notes that the A 645 lenses carry contacts inside the mount for the body’s program and shutter-priority modes, which is what the A on the front ring and the green A position on the aperture ring mean.

When the autofocus 645N arrived in 1997 the lens became the smc PENTAX-FA 645 75mm F2.8. Ricoh Imaging’s spec page gives 6 elements in 5 groups, f/22, 8 blades, 0.6 m, 0.18× and 58 mm again, at 74.5 × 37.5 mm and 215 g; the glass did not change, the barrel did. The FA adds a screwdrive coupler for the body’s motor and an AF/MF switch, and drops 25 g by using more plastic. Both versions take the same RH-A 58 mm hood and S80-80 case. An A lens on a 645N or 645NII focuses manually; an FA lens on the original 645 does the same (Japanese Wikipedia). The FA stayed in the catalogue through the 645D and 645Z, at $699.95 on Ricoh’s US page, and is now marked discontinued in Japan without a date.

Reviewers do not disagree about the optics. The PentaxForums database has 18 user reviews of the A at a 9.50 average and 14 of the FA at 9.38, every one a recommendation; Eric Woods on 35mmc sold his other 645 lenses once he had the FA 75; Niiro Sho, shooting it on a 645Z for Kitamura’s ShaSha, found it extremely sharp at the point of focus even at f/2.8 and free of distortion worth correcting. The recurring caveats are small ones: a little chromatic aberration in high-contrast scenes, bokeh that can be busy, corners that want f/5.6 to f/8, and a hood against side light. Jonathan Mac, who has owned both, calls the two optically the same and prefers the A for its sturdier barrel and better-damped focusing ring; several FA owners call its barrel flimsy, its AF/MF switch awkward and its rotating focus ring a nuisance.

Buying is straightforward. Check that the aperture ring clicks firmly (a loose ring is reported on used A lenses of this line), that the focus ring on an FA is not loose (one reviewer sent his to Pentax for an overhaul), and that the glass is clear; the A lenses are described as easy to open for cleaning. The choice between A and FA is a choice of body: manual focus and a metal barrel for the 645, autofocus for the N bodies and the digital 645s. A leaf-shutter LS 75mm f/2.8 exists for flash work and is a different lens. No launch price in yen or dollars was found for either version.

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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 taken with the SMC Pentax-A / FA 645 75mm f/2.8
Pentax 645 with a 75 mm lens (the file does not say whether A or FA) — Dudhhr, via Wikimedia Commons (CC BY-SA 4.0)

Sample photo wanted — shot with a SMC Pentax-A / FA 645 75mm f/2.8? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $650 across 25 fixed-price listings on 2026-09-19 (middle half $440–$970). First day tracked.

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

Show 28 more listings

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 2026-09-19. Links go to the shop or marketplace that carries the item.

Related: SMC Pentax-A 645 150mm f/3.5 · SMC Pentax-A / FA 645 35mm f/3.5 · SMC Pentax-A / FA 645 45mm f/2.8

Sources (10)

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.