Originally posted by clackers The 24-28 mm range gives a human eye kind of perspective and is the most versatile kind of focal length, which is why it's used by all the fixed lens cameras like the Ricoh GR, Nikon 1, Fuji X100, Sigma DP, et al.
Field of View depends on both focal length and sensor size. I believe those cameras have several different sensor sizes, and thus different fields of view, even if they have the same focal length.
24mm is only "normal" field of view on a sensor smaller than APS-C.
All Pentax DSLRs have APS-C sized sensors, so a "normal" lens is closer to 35mm.
Interestingly, many people find a slightly wider angle view to be a little more natural looking than actual human field of view. Also, it gives you some room to crop.