Pentax made one frustrating strategic mistake with the K1: it should have been a mirrorless camera shipped with one 35mm f/2.8 Otus-grade lens, along with optional adapters for Nikon and Canon DSLR lenses. As it stands, Pentax K lens selection is quite limiting and it’s yet another DSLR.
A relative weakness for full-frame Pentax is lenses. So the new 15-30mm is a key lens for the Pentax K1, and one that will be a primary test lens during my review.
Native mount lenses
Existing lenses designed for Pentax APS-C sensor size can of course be used on the Pentax K1, certainly in APS-C crop mode. Some of these even fill the full frame, or nearly so, at least over some portion of the range, so the full frame sensor can be mostly, perhaps even fully utilized (though with likely quality limitations). See my reviews of the Pentax limited lenses as well as my evaluations of the three Zeiss Touit APS-C lenses on full frame Sony, like the Touit 12mm f/2.8 Distagon.
Some of these will surely be disappointing, and some will be excellent. The underlined lenses I am likely to review (15-30mm for sure). Depending on response when I start reviewing the K1, I may do more than the ones marked shown underlined.
- Pentax HD PENTAX-D FA 15-30mm f/2.8 ED SDM WR. Along with the built-in rise and fall and shift in the K1, this might prove to be a versatile performer for architecture.
- Pentax HD Pentax-D FA 24-70mm f/2.8ED SDM WR
- Pentax smcP FA 31mm f/1.8 Limited
- Pentax SMCP-FA 43mm f/1.9 Limited
- Pentax Telephoto SMCP-FA 77mm f/1.8
- Pentax smc Pentax-D FA 100mm f/2.8 WR Macro Lens (maybe needs stopping down)
- Pentax HD PENTAX D FA* 70-200mm f/2.8 ED DC AW
- Pentax HD PENTAX D FA 150-450mm f/4.5-5.6 DC AW
- Various other older Pentax K lenses.
- View all Pentax full-frame lenses
The 31mm, 43mm and 77mm SMCP-FA Limited lenses probably aren’t great wide open, but if they are good at f/5.6 - f/8 they may be a dream kit for portability along with the 15-30mm for the wide end of the range.
This is not a complete list, but gives a good idea of the kind of stuff that is out there.
- Sigma 35mm f/1.4 DG HSM A. More Sigma ART lenses coming apparently all all are first-rate lenses. There are also various other Sigma lenses for Pentax, including a 15mm f/2.8 full-frame fisheye.
- 28mm, 50mm, 90mm Schneider PC-TS lenses. See reviews of all three Schneider PC-TS lenses in DAP.
- Rokinon 24mm f/3.5 ED tilt shift.
- Rokinon, Samyang, Tamron, see all 3rd-party full-frame Pentax K lenses.
Knut (K3 II user) writes:
One has to keep in mind, that the K1 is (to some extent) a present to the long term collector of Pentax lenses. These collectors do have access to some, maybe Zeiss classic grade lenses.
To me this is not an offer to lure Canon or Nikon users to Pentax (although some features are enticing).
Pentax lenses which are on Zeiss Classic level to my mind are:
- A Series: A 1,4/85; A1,8/135; A 4/200 macro
- FA Series: FA 1,8/31; FA 1,7/77; FA 2,8/200; DFA 2,8/200; FA 4,5/300; DFA 4/300
Unfortunately nothing under 31mm. Your review of the 15-30mm is thus definitely anticipated!
For a more complete picture testing the two limited lenses FA 1,8/31 and FA 1,8/77 would be very interesting. This would be extremely helpful to Pentax users.
Most Pentax-brand lens recommendations above are probably valid. Maybe some reservations on the DFA 100 macro before stopping down.
Pentax Normal SMCP-FA 50mm f/1.4: I’m skeptical. This a very classic design which does not pick up in resolution before f4-5,6. Lens design is identical for A 1,4/50; F 1,4/50; FA/1,4/50. It is a known secret that the A and F versions were built to more stringed requirements.
FA 150-450mm. According to Japanese testers it is superior to the CaNikon counterparts
DIGLLOYD: I plan on including the 31/1.8 or 77/1.8 in my review along with the 15-30mm.
Larry J writes:
Lloyd, you've really captured my attention the past few days with your coverage and commentary on the new FF Pentax. In mid 2014 I jettisoned my 67 ii and a select six-lens kit because I needed to make the move to digital and it seemed the promised Pentax entry was still 'way beyond the horizon. Since then I've been adapting to the digital approach to making picture with a 24 MP Nikon while missing the capture detail of the medium format. I want to move on to a higher pixel count body because I mostly print large (~20x30, ~24x40, etc.) which is now a stretch, but the D810 is a daunting investment.
So, along comes Pentax with a 36 MP body and you're giving it some serious scrutiny, praising its innovations, and I'm wondering if this merits my considering a system shift (my 3-lens kit is 16-35, 50 and 80-200).
I'd be interested in learning what you'd think of pairing the K-1 with the Sigma 35 Art: image quality, pros and cons of usage, etc. There were three Limited series lenses a while back that got good reviews. Would you expect the 77mm to stand up to the new sensor and perform its functions (AF, aperture, shutter) favorably when compared to other good contemporary lenses? Are there any other older K mounts to investigate? I value your insights, and I respect your position.
DIGLLOYD: I should have some feedback soon using the Sigma 35mm f/1.4 DG HSM Art on the K3 II (the full-frame K1 is not due to ship until April 10).
My guess is that the Pentax 31/1.8, 43/1.9 and 77/1.8 will be very good performers in an overall sense, including bokeh and rendering style, but that they will have some clear limits and probably will need f/5.6 - f/8 for corner to corner performance (and may have some field curvature and/or fsfocus shift issues—that’s speculation and remains to explore).
My expectation is that the Sigma Art lenses (20mm, 24mm, 35mm, 50mm) may be the best performers for the K1 (and very reasonably priced). That’s assuming Sigma brings the 20/24/50mm options to Pentax (35mm is th only option at present). The 20mm and 50mm options are particularly attractive for the K1. However, the Sigma f/1.4 DG HSM ART lenses are rather large and heavy compared to the Pentax 31mm, 43mm and 77mm.