"As of the time of this review the system offers 5 lenses - two "kit" lenses, a fisheye lens and two "toy" lenses. This review will focus on the Pentax-01 Standard Prime 8.5mm f/1.9. The first thing that we'll get used to is the focal length here. APS-C or micro-four-thirds lens specs are

more or less familiar among "serious" users but 8.5mm sounds odd here. This relates to the size of the camera sensor which has a crop factor of 5.5x so in full format terms we are talking about "47mm" thus a standard lens. Now this is not the full story. The max. aperture of f/1.9 sound fast and it is terms of light gathering. However, if you apply the cropping factor (f/1.9x5.5 = ~f/10.4) things will appear not all that sexy anymore regarding the depth-of-field potential. You can still achieve some basic object isolation with this lens but only if you move very close to your subject."