Konica AR — flange distance, protocol, and adapter compatibility
Konica's bayonet mount for the Auto-Reflex range, introduced in 1965 and produced until Konica exited camera manufacturing in 1987. Notable for the unusually short 40.5 mm flange — one of the shortest of any 35 mm SLR mount — which leaves Konica AR lenses extremely difficult to adapt onto longer-flange DSLRs. They adapt trivially onto mirrorless bodies (Sony E, Fujifilm X, MFT, Canon RF). Konica's optical line was strong: Hexanon primes (40 mm f/1.8, 57 mm f/1.2, 135 mm f/3.2) are highly regarded by manual-focus cinematographers and stills shooters working on mirrorless.
Mount specifications
Flange focal distance
40.5 mm
Throat diameter
40 mm
Electronic protocol
Mechanical only (no electronic coupling)
Supported formats
full-frame, APS-C
Manufacturer
Konica
Introduced
1965 (discontinued)
Status
Discontinued
Konica AR on the flange-distance axis
Konica AR sits at 40.5 mm — highlighted in orange below. The flange-distance gap between the mirrorless and SLR clusters is the room a mechanical adapter occupies; that gap is why almost every SLR lens adapts onto every mirrorless body, and why the reverse is mechanically impossible.
Flange clearance is only -3.5 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Canon EF (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -3.5 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Canon EF-S (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -1.5 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Canon FD (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -6.0 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Nikon F (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -4.0 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Sony A / Minolta A (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -5.0 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a M42 (Pentax / Praktica screw mount) (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -5.0 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Pentax K (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -11.5 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a PL (Positive Lock) (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -3.5 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Canon EF (cine) (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -4.2 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Exakta (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -3.9 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Praktica B (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -3.0 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Minolta SR / MC / MD (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -5.5 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Olympus OM (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Flange clearance is only -5.0 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Speed Booster equivalence calculator
Plug in any Konica AR lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Contax/Yashica (C/Y) (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
Effective focal length
35.5 mm
50.0 mm × 0.71 on the reducer.
Effective aperture
f/1.28
0.99 stops brighter than f/1.80.
Full-frame equiv. angle of view
53.3 mm
35.5 mm × 1.5× (APS-C sensor crop).
A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = −2 · log₂(ratio)). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Adapting other lenses onto a Konica AR body
You own a Konica AR body and want to mount glass from other systems. Mirrorless-lens-onto-DSLR-body combinations are omitted (rear element collides with the mirror box).
Flange clearance is only 1.5 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required.
Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Can Konica AR lenses adapt to a Canon EF or Nikon F DSLR?
No — Konica AR's 40.5 mm flange is shorter than both Canon EF (44 mm) and Nikon F (46.5 mm). A pure mechanical adapter cannot reach infinity focus; it would need a focal-reducing lens element, which only specialty Konica-AR-to-EF adapters with corrective glass provide, and even those degrade image quality. AR adapts cleanly onto every mirrorless mount instead (Sony E, Canon RF, Nikon Z, Fujifilm X, MFT).
Which Konica AR (Hexanon) lenses are worth seeking?
Hexanon AR 57 mm f/1.2 (rare, $600+), 40 mm f/1.8 (the famous "pancake" Hexanon, very sharp, $80-150), 50 mm f/1.7 (common, excellent value at $30-60), 135 mm f/3.2 (sharp portrait tele, $50-100), 35 mm f/2 (well-corrected wide, $100-200). The Hexanon line is regarded for sharpness and tonality that rivals contemporary Nikkor and Zuiko primes from the same 1965-1985 era.
Why did Konica AR have such a short flange?
Konica's engineers prioritised compact body size with the original Auto-Reflex line (1965) and never lengthened the flange in subsequent revisions (Autoreflex T, Autoreflex T3, FS-1). The decision constrained future SLR-to-SLR compatibility but turned out to be advantageous for modern mirrorless adaptation — the short flange leaves abundant room for an adapter onto Sony E (18 mm), Fujifilm X (17.7 mm), or Canon RF (20 mm).