Illustration, not a product photo.
Pentax K-3 Mark III
Probably the last great APS-C DSLR. Huge optical viewfinder, IBIS and full weather sealing.
Overview
The Pentax K-3 Mark III is a 2021 APS-C 25.7MP DSLR on the Pentax K mount. It shoots up to 12 frames per second, records 4K 30p video and has in-body stabilisation, and it's weather sealed. Probably the last great APS-C DSLR. Huge optical viewfinder, IBIS and full weather sealing.
It's best suited to landscape, wildlife & animals, sports & action. In our database, 13 lenses fit it natively (4 from third-party makers such as Samyang, Sigma).
MPB had none listed on 5 November 2026; check the dealers below for new or used examples.
Key specifications
| Released | 2021 |
| Type | DSLR |
| Sensor | APS-C (23.5×15.6mm, 1.5× crop) |
| Resolution | 25.7 megapixels |
| Max burst | 12 fps |
| Sensor readout | Mechanical shutter (DSLR) |
| Max ISO | 1,600,000 |
| Low-light score | 3.25/5 |
| Stabilisation | In-body (IBIS) |
| Viewfinder | Optical |
| Video | 4K 30p |
| Weather sealed | Yes |
| Weight | 820 g with battery |
| Mount | Pentax K |
- APS-C sensor: about 1.5× extra reach from every lens
- In-body image stabilisation with every lens
- Weather sealing for rain and dust
- Optical viewfinder with zero lag and long battery life
- DSLR: no subject-detection autofocus through the viewfinder, and lens development has stopped
- Older autofocus generation; check shutter count and battery health when buying used
- Heavy body at 820g
Compatible lenses
13 native in our database
| Lens | Fit | Focal | Aperture | Weight | New ≈ | Used (MPB) | |
|---|---|---|---|---|---|---|---|
| Pentax HD FA 50mm f/1.8 Portraits | Native First-party | 50mm | f/1.8 | 122g | £199 | — | |
| Samyang 14mm f/2.8 ED AS IF UMC (manual) Astrophotography · Landscape | Native Third-party (manual focus) | 14mm | f/2.8 | 552g | £299 | £112–349 | |
| Sigma 17-50mm f/2.8 EX DC OS HSM Everyday & travel | Native Third-party | 17-50mm | f/2.8 | 565g | £349 | £63–264 | |
| Pentax HD DA 55-300mm f/4.5-6.3 ED PLM WR RE Wildlife & animals · Sports & action | Native First-party | 55-300mm | f/4.5-6.3 | 442g | £399 | £84–344 | |
| Pentax HD DA 16-85mm f/3.5-5.6 ED DC WR Everyday & travel | Native First-party | 16-85mm | f/3.5-5.6 | 488g | £549 | £294 | |
| Sigma 18-35mm f/1.8 DC HSM Art Everyday & travel · Portraits · Vlogging & video | Native Third-party | 18-35mm | f/1.8 | 810g | £649 | £294–459 | |
| Sigma 35mm f/1.4 DG HSM Art Everyday & travel · Portraits · Astrophotography | Native Third-party | 35mm | f/1.4 | 665g | £699 | £399–419 | |
| Pentax HD DA 11-18mm f/2.8 ED DC AW Landscape · Astrophotography | Native First-party | 11-18mm | f/2.8 | 704g | £899 | £659 | |
| Pentax HD D FA 24-70mm f/2.8 ED SDM WR Everyday & travel | Native First-party | 24-70mm | f/2.8 | 787g | £1,099 | £289–399 | |
| Pentax HD D FA* 50mm f/1.4 SDM AW Portraits | Native First-party | 50mm | f/1.4 | 910g | £1,099 | £389–419 | |
| Pentax HD D FA 70-210mm f/4 ED SDM WR Sports & action | Native First-party | 70-210mm | f/4 | 980g | £1,099 | — | |
| Pentax HD D FA 15-30mm f/2.8 ED SDM WR Landscape · Astrophotography | Native First-party | 15-30mm | f/2.8 | 1040g | £1,399 | — | |
| Pentax HD D FA 150-450mm f/4.5-5.6 ED DC AW Wildlife & animals | Native First-party | 150-450mm | f/4.5-5.6 | 2000g | £1,999 | £1,049–1,179 |
Batteries and memory cards
Pentax D-LI90 · maker's battery about £71
Battery for the K-1 series and K-3 Mark III. Carry at least one spare.
2× SD (UHS-II)
A V30 UHS-I card is enough for stills; a V60 UHS-II card clears bursts faster.
How the K-3 Mark III compares
Where to buy
*Used prices on this site come from MPB on 5 November 2026. MPB only lists what it has bought in, so "None listed" means none in their stock that day, not that Pentax K-3 Mark III is hard to find. Check these trusted UK dealers too.
See example photos
Real-world shots taken with the Pentax K-3 Mark III. Results are searches on each site, so check the camera or lens listed in each photo's details.
Frequently asked questions
Is the Pentax K-3 Mark III good for landscape?
Yes. APS-C sensor: about 1.5× extra reach from every lens. In-body image stabilisation with every lens. Pair it with a wide zoom (about 16–35mm equivalent) with a front filter thread for ND and polariser filters.
Is the Pentax K-3 Mark III good for wildlife & animals?
Yes. APS-C sensor: about 1.5× extra reach from every lens. In-body image stabilisation with every lens. Pair it with as much reach as you can carry: 400–600mm equivalent or more.
What lenses fit the Pentax K-3 Mark III?
It uses the Pentax K mount. 13 lenses in our database fit natively, including 4 third-party options.
How much is a used Pentax K-3 Mark III?
MPB had none listed when we checked on 5 November 2026. That reflects MPB's stock on the day, not availability: try the other dealers below.
Does the Pentax K-3 Mark III have image stabilisation?
Yes, it has in-body image stabilisation (IBIS), so every lens is stabilised.