Pentax SMC Pentax 67 105mm f/2.4

Overview

The 105mm f/2.4 is the standard "normal" lens for the Pentax 67 family, and is widely regarded as one of the finest 105mm medium-format normals ever manufactured — frequently cited alongside the Hasselblad 80mm f/2.8 Planar and the Mamiya 80mm f/1.9 as one of the standout normals of the medium-format era. Its combination of a fast f/2.4 maximum aperture (unusually wide for a 6×7 normal — the 105mm covers a much larger image circle than any 35mm 50mm normal), a compact-for-its-class form factor, and a much-praised "3D" rendering character has made the lens an enduring reason photographers buy into the Pentax 67 system.^[1]

In 35mm-equivalent terms, 105mm on 6×7 (56×70mm) corresponds to roughly 52mm full-frame — a nominal "normal" lens. In practical use, the lens behaves as a slightly-wider-than-50mm with the depth-of-field shallowness of a fast 80mm — a distinctive look that's hard to replicate on smaller formats without exotic optics.

The 105mm position in the Pentax 67 lens line

The 105mm f/2.4 occupies the most-sold position in the Pentax 67 lens lineup. Pentax also offered a 90mm f/2.8 LS leaf-shutter lens at a similar focal length, but the 90mm LS is a different optical design optimized for flash sync rather than wide aperture; the 105mm f/2.4 is the optical-quality / wide-aperture choice.^[2] Other neighboring lenses in the line:

• 75mm f/4.5 / 75mm f/2.8 AL — wide-normal alternatives; popular for environmental portraits and landscape
• 90mm f/2.8 LS — leaf-shutter portrait/wide-normal; same focal-length neighborhood but shutter-in-lens for 1/500 flash sync
• 150mm f/2.8 (later in production) — short-tele alternative with similar bokeh quality

For most Pentax 67 photographers, the 105mm f/2.4 is the lens that comes with the body and rarely leaves it.

Optical design

The 105mm f/2.4 uses a 6-element, 5-group design — this formula is consistent across all three production versions (Super Takumar, SMC Takumar, SMC Pentax 67). It's a near-Planar variant: roughly symmetric about the diaphragm with paired front and rear groups, well-corrected for spherical and coma aberrations and producing the smooth out-of-focus rendering the lens is known for.

The maximum aperture of f/2.4 is unusually wide for a medium-format normal — by comparison, the Hasselblad 80mm Planar is f/2.8, the Mamiya 645 80mm is f/1.9 (faster but smaller image circle), the Bronica GS-1 100mm is f/3.5. The f/2.4 figure was chosen to allow handheld shooting at moderate ISO film speeds despite the large mirror's vibration limits — a half-stop more than f/2.8 mattered when shooting Tri-X 400 in available light.

The three versions and the thorium-glass story

The 105mm f/2.4 was sold in three versions across its long production life. All three share the same 6-element / 5-group optical formula — what changes is the coating technology and (in the third version) the glass itself.^[1]

Version 1: Super-Takumar 6×7 105mm f/2.4 (1969)

• Original release alongside the Pentax 6×7 body in 1969.
• Single-layer anti-reflective coating ("Super-Multi-Coated" branding had not yet arrived).
• Thorium-bearing glass in one or two elements — used to achieve the high refractive index needed for the wide aperture without enlarging the lens. Thorium glass is mildly radioactive and yellows over decades of exposure to its own beta radiation.
• Mid-life "Super Takumar" examples may show visible yellowing tinting their imagery slightly warm; the yellowing can be partially reversed by extended UV exposure (sunlight or UV lamp for several days).

Version 2: SMC Takumar 6×7 105mm f/2.4 (1971)

• Super-Multi-Coated upgrade — Pentax's then-new multi-layer anti-reflective coating, significantly improving flare resistance and contrast over the single-coated original.
• Same optical formula, same thorium glass. Yellowing risk persists.
• Often considered the "sweet spot" version — significantly better coatings than version 1, slightly more rounded optics in some samples vs. version 3, lower used-market price than version 3.

Version 3: SMC Pentax 67 105mm f/2.4 (1989)

• Released alongside the renamed Pentax 67 body.
• Thorium glass replaced with non-radioactive high-index glass of equivalent optical properties. No yellowing, no radiation concerns.
• Latest-generation SMC coating — generally regarded as having the best contrast and flare resistance of the three versions.
• Mechanical updates: tighter focus barrel tolerances, refined aperture click stops.
• Most common version on the current used market; trades for the highest prices.

The version most photographers want depends on their priority: version 3 for clean glass and best coating, version 2 for the coating + lower price + the option to "de-yellow" via UV exposure, version 1 only for collectors or for those willing to deal with the yellowing as a creative warm cast.

Distinguishing optical character

What makes the 105mm f/2.4 "the legendary normal" — beyond spec-sheet figures — is a combination of qualities reviewers consistently identify:

• Sharp wide open at f/2.4. Most fast normals require stopping down 1-2 stops to reach optimal sharpness; the 105mm f/2.4 is usable at maximum aperture with only a slight contrast drop vs. f/4–f/5.6.
• Smooth, painterly out-of-focus rendering. The 9-blade aperture remains close to circular through most of its range; out-of-focus highlights (specular bokeh balls) appear nearly round at all but the smallest apertures.
• "3D" subject separation. A distinctive characteristic where in-focus subjects appear to "pop" from the background — a function of the lens's microcontrast curve and its smooth defocus transition.
• Low chromatic aberration even at f/2.4. The 6-element design is well-corrected for the wavelengths most-relevant to portrait skin tones; LoCA (longitudinal chromatic aberration) is minimal for a fast MF normal.
• Field curvature is mild. Edge sharpness at f/2.4 is reasonable on a flat subject and improves quickly stopped down to f/5.6 — well-suited to environmental portraiture where the subject is centered and edges are typically beyond the depth of field.

The lens has effectively no flare or ghosting issues at the SMC version's coating level — backlit subjects can be photographed at f/2.4 with strong sources just outside the frame without veiling flare.

Working notes

• 67mm filter thread. Standard size; 67mm filters are widely available and not expensive. Polarizers and ND filters in 67mm are inexpensive new and commonly available used.
• Lens hood (PH-RC 67) is highly recommended. The wide front element benefits significantly from a deep hood. Aftermarket 67mm hoods work; the original Pentax PH-RC 67 is a deep tulip-shape that protects the front element well.
• Mounts on the inner bayonet. All Pentax 67 lenses 35mm–300mm focal length mount to the inner bayonet ring; the 400mm and longer lenses use the outer ring.
• Manual focus only. No version of the 105mm f/2.4 was ever AF — the Pentax 67 system was MF throughout its life. The focus barrel has a long throw (~270° from minimum focus to infinity) for precise focus at f/2.4.
• Compatible with all Pentax 67 bodies including the 67II. The 67II's AE pentaprism meters through the lens normally; the older bodies' optional TTL pentaprisms also meter correctly.

Used market and version selection

Used pricing as of 2026 (US market, varies by condition):

• SMC Pentax 67 105mm f/2.4 (1989+): $400–700 for excellent condition; $300–500 for good with normal wear.
• SMC Takumar 6×7 105mm f/2.4 (1971–1989): $250–500. Yellowing examples lean toward the lower end.
• Super-Takumar 6×7 105mm f/2.4 (1969–1971): $200–400. Yellowing is common; price reflects.

When selecting on the used market, key things to verify:

• Glass clarity — yellowing on Takumar versions is the main one to check.
• Aperture blade condition — should be dry (no oil), should snap to each click stop crisply.
• Focus barrel — should be smooth without binding or stiffness; lubrication degrades over time.
• Coating integrity — front and rear elements should be free of deep cleaning scratches; coating should look uniform.
• Mount condition — bayonet flange should be clean and undamaged; some used examples have flange wear.

A CLA (clean, lubricate, adjust) for any of these versions runs $150–250 from a competent service shop and is a worthwhile investment on a $300–700 lens that can then last decades.

Related lenses

• Pentax 67 55mm f/4 — moderate wide-angle for 6×7; the most common wider-than-normal companion to the 105mm f/2.4
• Pentax 67 75mm f/4.5 — wide-normal; bridges the gap between 55mm and 105mm
• Pentax 67 90mm f/2.8 LS — leaf-shutter alternative at a similar focal length; flash-sync at 1/500
• Pentax 67 165mm f/4 LS — short telephoto / portrait lens; also notable for its rendering
• Pentax 67 200mm f/4 — long portrait / short telephoto

Related cameras

• Pentax 67 — primary host body for this lens (1969–1998 family)
• Pentax 67II — successor body (1998–2009); the 105mm f/2.4 mounts directly with full functionality