Originally posted by paperbag846 Red dot is inaccurate, green hexagon is accurate.
Well, my K-m has only a green hexagon, and it certainly isn't accurate for MF confirmation (not with most of my lenses, anyway).
Actually, I don't think it's all that surprising that the AF mechanism doesn't appear to cope with all FLs, apertures and lenses. After all, it seems to need to know exactly which AF lens is mounted for accurate AF (and even then may need to be tweaked), so why should it be able to give good focus indication for any old MF lens?
Basically, the phase-detect AF mechanism, whilst being straightforward enough in principle, actually needs a large dose of black magic to work properly.