Pentax K Lenses
60 interactive lens diagrams
Pentax K bayonet, introduced in 1975 | 35 mm film, APS-C digital, and full-frame digital
Pentax K replaced M42 screw mount with a bayonet while preserving a strong continuity ethos. Introduced in 1975, the mount has evolved through manual-aperture lenses, A-series electronic aperture information, autofocus KAF variants, digital APS-C DSLRs, and full-frame K-1 bodies.
The K mount is unusually adapter-friendly and backward-compatible compared with many camera systems, though features such as aperture control, autofocus drive, and electronic contacts vary by generation. Pentax's official M42 adapter also made the transition from screw mount less abrupt for photographers with existing Takumar lenses.
Its lens history includes compact Limited primes, rugged DA and D FA lenses, classic SMC coatings, and broad third-party support from the film era onward. K-mount pages are useful for comparing a long-running SLR bayonet that survived autofocus and digital without being abandoned.
Mount interface
Flange focal distance 45.46 mm, bayonet mount. 0° at 12 o'clock from the camera front; the lens-side view is the horizontal mirror. Dotted strokes mark photo-scaled or schematic (not-to-scale) dimensions.
Throat / openingMount ringBayonet lug / slotLock pin / notchIndex markElectrical contactMechanical couplingScrews / sealsDatum & axis
LAOWA 105mm f/2 Smooth Trans Focus (STF)— 11 ELEMENTS / 8 GROUPS, DESIGN f = 102.26 mm, DESIGN F/2.05LAOWA 12mm f/2.8 Zero-D— 16 elements / 10 groups, Design f = 12.4999 mm, Design Fno = 2.87LAOWA 15mm f/4 Wide Angle 1:1 Macro— 12 ELEMENTS / 9 GROUPS, f = 16.00 mm, F/4.1LAOWA 24mm f/14 2× Macro Probe— 27 ELEMENTS / 19 GROUPS, f ≈ 23.7 mm, F/14MINOLTA AF 28-75mm f/2.8 (D)— 28-75mm f/2.8, 16 elements / 14 groups, 4 hybrid aspherical surfacesPENTAX DA 21mm f/3.2 AL Limited— 8 elements / 5 groups, f = 21.60 mm design; 21 mm nominal, F3.2 marketed; F3.3 patent designPENTAX DA 35mm f/2.8 Macro Limited— 9 elements / 8 groups, 35 mm marketed; 34.41 mm patent EFL, f/2.8 marketed; 1:2.88 patent FNOPENTAX DA 70mm f/2.4 Limited— 6 elements / 5 groups, 70 mm (scaled from patent f=67.74), f/2.4 nominal; patent FNO 1:2.5PENTAX DA* 16-50mm f/2.8 ED AL [IF] SDM— 15 ELEMENTS / 12 GROUPS, f = 16.48–48.50 mm (2.94×), F/2.8 (constant)PENTAX DA* 50-135mm f/2.8 ED [IF] SDM— 18 ELEMENTS / 14 GROUPS, f = 51.5–131.0 mm (patent) / 50–135 mm (marketing), F/2.8 (constant)PENTAX F 85mm f/2.8 Soft— 5 ELEMENTS / 4 GROUPS, f ≈ 85.0 mm, F/2.8PENTAX FA 31mm f/1.8 AL Limited— 9 ELEMENTS / 7 GROUPS, f ≈ 31.8 mm, F/1.8PENTAX HD D FA 150-450mm f/4.5-5.6 ED DC AW— Marketed 150–450mm f/4.5–5.6, Design f = 153.50–440.00 mm, Design F/4.6–5.7PENTAX HD D FA 21mm f/2.4 ED Limited DC WR— 11 elements / 8 groups, f = 21.32 mm design, F2.4 nominal / F2.45 designPENTAX HD D FA 28-105mm f/3.5-5.6 ED DC WR— 15 ELEMENTS / 11 GROUPS, PATENT f = 28.70–102.38 mm, PATENT f/3.6–5.7PENTAX HD D FA* 50mm f/1.4 SDM AW— 15 elements / 9 groups, f = 49.57 mm design, F1.45 design / F1.4 nominalPENTAX HD D FA* 70-200mm f/2.8 ED DC AW— 19 ELEMENTS / 15 GROUPS (PATENT), 19 ELEMENTS / 16 GROUPS (MARKETED), 70-200mm f/2.8 (MARKETED)PENTAX HD D FA* 85mm f/1.4 ED SDM AW— 12 elements / 10 groups, f = 83.41 mm design; 85 mm marketed, F1.46 design; F1.4 marketedPENTAX HD DA 16-85mm f/3.5-5.6 ED DC WR— 16 ELEMENTS / 12 GROUPS, 16-85mm f/3.5-5.6 (marketing), 16.48-82.45mm, modeled f/3.565-5.776 (Example 1)PENTAX HD DA 18-50mm f/4-5.6 DC WR RE— 11 ELEMENTS / 8 GROUPS, 18-50mm F4-5.6, 0.3m MFDPENTAX HD DA 20-40mm f/2.8-4 ED Limited DC WR— 9 ELEMENTS / 8 GROUPS, 20–40mm f/2.8–4 (production), 20.60 / 30.00 / 39.00 mm (patent)PENTAX HD DA 55-300mm f/4.5-6.3 ED PLM WR RE— 14 ELEMENTS / 11 GROUPS, DESIGN f = 56.50–291.19 mm, DESIGN F/4.60–6.48PENTAX HD DA* 11-18mm f/2.8 ED DC AW— 16 ELEMENTS / 11 GROUPS, 11–18 mm MARKETING / 11.25–17.70 mm DESIGN, F/2.8 CONSTANTPENTAX SMC A ZOOM 35-70mm f/4— 7 ELEMENTS / 7 GROUPS, 35-70mm f/4 (MARKETED), 36-68.5mm f/4.1 (PATENT)PENTAX SMC A* 135mm f/1.8— 7 elements / 6 groups, f = 134.99 mm, F/1.8PENTAX SMC A* 200mm f/4 MACRO ED— 10 elements / 9 groups, f = 199.98 mm design, F/4PENTAX SMC DA 16-45mm f/4 ED AL— 13 ELEMENTS / 10 GROUPS, 16-45 mm f/4 MARKETING, 16.30-43.70 mm / F4.1 MODELPENTAX SMC DA 17-70mm f/4 AL [IF] SDM— 17 ELEMENTS / 12 GROUPS, DESIGN 17.50–67.89 mm, F/4.1 MODELEDPENTAX SMC DA 18-55mm f/3.5-5.6 AL— 12 ELEMENTS / 9 GROUPS, 18-55mm f/3.5-5.6 (marketing), Design f = 19.10-55.16 mmPENTAX SMC FA 100-300mm f/4.7-5.8— 11 ELEMENTS / 9 GROUPS, DESIGN f = 103.00–290.04 mm, DESIGN F/4.8–6.0PENTAX SMC FA 20-35mm f/4 AL— 10 ELEMENTS / 8 GROUPS, DESIGN f = 20.60-34.01 mm, DESIGN F/4PENTAX SMC FA 28-105mm f/4-5.6 POWER ZOOM— 13 ELEMENTS / 11 GROUPS, DESIGN f = 29.02–101.60 mm, DESIGN F/4.1–5.8PENTAX SMC FA 28mm f/2.8 Soft— 5 elements / 5 groups, f = 28 mm, F/2.8 nominal; patent F.No. 1:2.9PENTAX SMC FA J 75-300mm f/4.5-5.8 AL— 12 ELEMENTS / 10 GROUPS, DESIGN f = 77.25–289.96 mm, DESIGN F/4.6–6.2PENTAX SMC FA* 28-70mm f/2.8 AL— 14 ELEMENTS / 11 GROUPS, DESIGN f = 29.00–68.00 mm, DESIGN F/2.8PENTAX SMC FA* 300mm f/4.5 ED [IF]— 9 ELEMENTS / 7 GROUPS, DESIGN f = 300.06 mm, DESIGN F/4.5PENTAX SMC FA* 80-200mm f/2.8 ED [IF]— 16 ELEMENTS / 13 GROUPS, DESIGN f = 81.63–196.00 mm, DESIGN F/2.8SAMYANG 100mm f/2.8 ED UMC MACRO— 15 ELEMENTS / 12 GROUPS, DESIGN f = 98.04 mm, DESIGN F/2.9SAMYANG 135mm f/2 ED UMC— 11 ELEMENTS / 7 GROUPS, DESIGN f = 130 mm, DESIGN F/2.07SIGMA 15mm f/2.8 EX DG DIAGONAL FISHEYE— 7 ELEMENTS / 6 GROUPS, DESIGN f = 15.3 mm, DESIGN F/2.8SIGMA 18-35mm f/1.8 DC HSM | Art— 17 ELEMENTS / 12 GROUPS, DESIGN f = 18.60–33.78 mm, DESIGN F/1.86SIGMA 24-70mm f/3.5-5.6 ASPHERICAL HF— 9 ELEMENTS / 7 GROUPS, DESIGN f = 25.0-67.6 mm, DESIGN F/3.62-5.79SIGMA 24mm f/1.8 EX DG ASPHERICAL MACRO— 10 ELEMENTS / 9 GROUPS, DESIGN f = 24.69 mm, DESIGN F/1.85SIGMA 28mm f/1.8 EX DG ASPHERICAL MACRO— 10 ELEMENTS / 9 GROUPS, DESIGN f = 27.10 mm, DESIGN F/1.86SIGMA 30mm f/1.4 DC HSM | Art— 9 elements / 8 groups, f = 30.785 mm design, F1.4 marketed / F1.46 designSIGMA 35mm f/1.4 DG HSM | Art— 13 elements / 11 groups, f = 35.16 mm design, F1.45 design / F1.4 marketedSIGMA 4.5mm f/2.8 EX DC CIRCULAR FISHEYE HSM— 13 ELEMENTS / 9 GROUPS, DESIGN f = 4.45 mm, DESIGN F/2.9SIGMA 70-300mm f/4-5.6 DG OS— 16 ELEMENTS / 11 GROUPS, DESIGN f = 70.33-290.5 mm, DESIGN F/4.15-5.84SIGMA 85mm f/1.4 EX DG HSM— 11 ELEMENTS / 8 GROUPS, DESIGN f = 83.58 mm, DESIGN F/1.46SIGMA APO 50-500mm f/4.5-6.3 DG OS HSM— 22 ELEMENTS / 16 GROUPS, DESIGN f = 51.50–485.00 mm, DESIGN F/4.57–6.47SIGMA MACRO 70mm f/2.8 EX DG— 10 ELEMENTS / 9 GROUPS, DESIGN f = 68.91 mm, DESIGN F/2.88TAMRON AF 28-200mm f/3.8-5.6 Super XR Aspherical [IF] MACRO— 28-200mm marketing / 29.07-193.0mm patent design, 15 PHYSICAL LENS PIECES / 14 GROUPS, 3 COMPOSITE ASPHERICAL LENSESTAMRON AF 28-300mm f/3.5-6.3 XR Di LD Aspherical [IF] MACRO— 28-300mm marketed / 28.9958-289.5284mm modeled, f/3.5-6.3 marketed / f/3.50-6.50 patent wide-open, 13 groups / 15 physical lens piecesTAMRON SP AF 17-50mm f/2.8 XR Di II LD Aspherical [IF] (A16)— 16 ELEMENTS / 13 GROUPS, DESIGN f = 17.40–48.50 mm, DESIGN F/2.88TAMRON SP AF 28-75mm f/2.8 XR Di LD Aspherical [IF] MACRO— 16 ELEMENTS / 14 GROUPS, DESIGN f = 28.87-72.65 mm, DESIGN F/2.91TAMRON SP AF 70-200mm f/2.8 Di LD [IF] MACRO— 18 ELEMENTS / 13 GROUPS, 70-200mm f/2.8 (MARKETING), 71.50-194.00mm F/2.88 (PATENT DESIGN)VIVITAR SERIES 1 35-85mm f/2.8 VMC— 12 ELEMENTS / 9 GROUPS, f ≈ 38.5–89.1 mm (patent: 36–83 mm), F/2.8VIVITAR SERIES 1 70-210mm f/3.5 VMC MACRO FOCUSING AUTO ZOOM— 15 ELEMENTS / 10 GROUPS, 70-210mm (PATENT 70-205mm), f/3.5 (PATENT 1:3.65)VOIGTLÄNDER APO-LANTHAR 180mm f/4 SL Close Focus— 9 ELEMENTS / 7 GROUPS, f ≈ 197.9 mm (patent) / 180 mm (marketed), F/4VOIGTLÄNDER MACRO APO-LANTHAR 125mm f/2.5 SL— 10 ELEMENTS / 9 GROUPS, f = 125.0 mm, F/2.5