Lens Options...

The lens mount on the Pentax K-01 is compatible with all of the company's K-mount lenses, with no adapter required. Be aware though that because it uses a lens mount originally designed for an SLR system, the K-01's longer flange-back distance makes it less flexible than its peers when it comes to mounting third-party lenses via adapters.

The K-01 can come bundled with three possible lenses, including the F2.8, 40 mm pancake lens you see below. This is the thinnest lens I've seen (0.36 inches!), and really a marvel of engineering. The lens, also apparently designed by Marc Newson (although actual optics are the same as the older SMC DA 40mm f/2.8), is very light (51 g) and is equivalent to 60 mm focal length when attached to the K-01.

The incredibly thin 40 mm pancake lens

The thing that bugged me the most about the lens is the small rubber lens cap that you snap into place - it doesn't like to stay put. The other two lenses are standard Pentax kit lenses, neither of which will win any awards. Whichever lens you end up using, don't forget that there's a 1.5X crop factor to keep in mind. And, since image stabilization is built into the body, every lens you attach (and you can use almost any K-mount lens on the face of the Earth) will have shake reduction.

...and Lens Issues

During the time I was working on this review I had a few issues with Pentax quality control (or rather the lack of it). The weeks I spent with the K-01 were frustrating. My original K-01 would produce out-of-focus photos about 50% of the time, with multiple lenses. I exchanged it for a second body, which did not have that issue. Lenses were a different story - here's a quick summary of my experiences:

  • F2.8, 40 mm pancake: my kit lens worked great - no complaints!
  • F3.5-5.6, 18-55 mm #1: returned it early on due to the blurry photos issue mentioned above; seemed okay aside from corner blurring.
  • F3.5-5.6, 18-55 mm #2: this lens arrived to replace 18-55 #1, and was a brand new water resistent (WR) model; it was decentered, meaning that sharpness drops off rapidly as you move away from the center of the frame; I did not have focusing problems with this particular lens.
  • F3.5-5.6, 18-55 mm #3: I bought this lens years ago just to have around, and used it to reshoot the photos taken with the WR model; this lens had the same blurriness issues as lens #1 did with my original K-01 body, but it did okay with the second one; this is a Mark I lens, so it had issues with vignetting that the other two 18-55's did not.
  • F2.8, 16-50 mm: this $1500 lens is in Pentax's DA* lineup, so I was expecting great things; it arrived brand new and guess what - it was decentered, too. My 18-55 actually produced sharper photos (see example below), with one exception.
  • F4.0-5.6, 50-200 mm: another one of the possible kit lenses, this lens also appeared to be decentered, and had horrible purple fringing which revealed itself during my first pass at night test shots.
  • F2.8, 50-135 mm: I borrowed this $1600 DA* lens from a friend to take over night shooting duty, and it worked great.
Below are crops from the third 18-55 ($200) and the 16-50 ($1500).
F3.5-5.6, 18 - 55 mm DA lens ($200) @ F7.1 - this is lens #3 mentioned above
Left side (100% Crop) Center (100% Crop)
F2.8, 16 - 50 mm DA* lens ($1500) @ F7.1
Left side (100% Crop) Center (100% Crop)

Unless I've had an incredible run of bad luck, it seems that quality control at Pentax needs some work. Having a defective camera body and two brand new decentered lenses is not what I'd expect from them. If you get a lens that is properly built and calibrated, then you'll get very nice results. If something seems amiss, however, keep exchanging it until you're happy. To be fair, Pentax isn't the only manufacturer with these kinds of issues (hello, Fujifilm), though this was considerably worse than my usual experiences.