The magnification ratio is the specification, and 1:1 is the dividing line · review
Pentax’s weather-resistant 100 mm f/2.8 macro for K-mount, the HD version of its long-running lens, at about $647 from Adorama with one unit left.
Pentax builds this lens for weather, with AW sealing and an SP fluorine coating on the front element that repels water drops and fingerprints.
One ED and two anomalous-dispersion elements control color fringing, and the circular diaphragm keeps out-of-focus highlights round down to f/5.6.
This is the HD PENTAX-D FA, successor to the smc lens our earlier page described. It adds a machined aluminum exterior.
Adorama sold it at about $647 with one unit left.
Prices quoted in this text were read on November 2, 2026. The live price is at the top of the page.
| Mount | Pentax K, full frame |
|---|---|
| Focal length | 100 mm |
| Aperture | f/2.8 |
| Magnification | 1:1 |
| Sealing | AW (All Weather) dustproof and weather-resistant |
| Optics | One ED and two anomalous-dispersion elements |
| Coating | SP (Super Protect) fluorine coating on the front |
| Diaphragm | Circular from wide open to f/5.6 |
| In the box | Soft case, hood, caps |
| Amazon reference | B0BJQF7WJ1 |
No. This listing is the HD version, with HD coatings and a new aluminum exterior. Our earlier page covered the older smc lens, now without a US offer.
Pentax lists dustproof, weather-resistant AW construction.
A 1:1 ratio, also written 1.0×, means the subject is projected onto the sensor at its real size. A 0.5× lens projects it at half size.
At $647, it is the 3 cheapest of the 9 models in this category published here.
8.2/ 10
The macro to own on a Pentax K body, built for wet and dusty days.
photo equipment from the same category, at nearby prices. Only what all of them publish is shown: a column with holes compares nothing.
| Model | Price | Mount | Focal length | Aperture | Magnification |
|---|---|---|---|---|---|
| Pentax HD D FA Macro 100mm F2.8 | $647 | Pentax K, full frame | 100 mm | f/2.8 | 1:1 |
| Sigma 105mm F2.8 EX DG OS Macro (F) | $654 | Nikon F, full frame; usable on DX | 105 mm | f/2.8 | 1:1 at 12.3 in (31 cm) |
| Canon RF 85mm F2 Macro IS STM | $589 | Canon RF, full frame | 85 mm | f/2 | 0.5× (half life size) |
| TAMRON SP 90mm F/2.8 VC Macro (EF) | $799 | Canon EF, full frame | 90 mm | f/2.8 | 1:1 |
This model is listed on Amazon.com, at ≈ $647 at the last reading. Listed is not the same as in stock: availability changes daily, and the buy box shows the live price.
Details checked on November 2, 2026.
Pentax K owners who shoot macro outdoors, in damp or dusty conditions.
Specifications: the manufacturer sheet for photo equipment and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
Canon RF, full frame · 85mm · f/2 · 0.5× maximum magnification · 1.15 ft (0.35 m) close focus · optical IS up to 5 stops · Hybrid IS · control ring
A bright 85 mm f/2 portrait lens that also focuses to half life size, with 5-stop stabilization, sold by Amazon.com for about $589. It is 0.5×, not true 1:1 macro.
Best for: Canon RF owners who want an 85 mm portrait lens that can also do close-ups of flowers and products.
≈ $589
Canon RF, full frame · 100mm · f/2.8 · 1.4× maximum magnification · IS up to 5 stops, Hybrid IS · SA control ring · L series
Canon’s RF L macro, the first medium telephoto macro lens to reach 1.4× according to Canon, with Hybrid IS and a bokeh-shaping control ring, sold by Amazon.com for about $1,349.
Best for: Canon RF macro photographers who want the most magnification with autofocus.
≈ $1,349
Canon EF, full frame · 100mm · f/2.8 · 1:1 macro · Hybrid IS · USM · L series · 2.05 lb (930 g) listed
Canon’s L-series EF macro lens with Hybrid IS, a long-time reference for 1:1 macro on DSLRs, at about $1,449 from a dealer. The listing itself gives almost no detail.
Best for: Canon DSLR owners who want a dependable 1:1 macro that doubles as a portrait lens.
≈ $1,449
