Originally posted by maltfalc 28mm would actually be way closer to giving a "normal" fov with aps-c, if that's what you're going for.
Closer than 30-35? That's what the original post specified.
I'm not sure I agree if that's what you are saying.
28mm FOV on APSC = 55 degrees diag / 46 degrees horz
31mm FOV on APSC = 50/42
35mm FOV on APSC = 45/38
50mm FOV on Full Frame = 47/40
43mm FOV on Full Frame = 53/45
55mm FOV on Full Frame = 43/36
58mm FOV on Full Frame = 41/34
40mm FOV on APSC = 39/33
So I'm not sure that 30-35 is any farther out of "normal" for APSC than the 28. Realistically 43 - 55 are all considered normal on FF and consequently I think we can say that 28-35 are all within spec for APSC normal lenses. The DA 40 is slightly narrower but still close to the longer normal lenses used in the film era. The "ideal spec" per Pentax is the 43mm but that's not a universally accepted lens for normal perspective.