Here is a report from Fstoppers – “Comments suggest the newly announced Pentax FA* 85mm f/1.4 is just a rehoused Sigma lens – probably not”:
“If Ricoh has rehoused the Sigma, my guess is that they’ve probably improved on this already incredible lens. Based on that, I don’t think anyone is going to be overly disappointed if that is the case. Taking a look at the filter threads on both lenses, the Pentax lens tapers on the top, and maybe that slight change allowed the smaller size. That in itself is a very useful change, because filters above 82mm are harder to find and more expensive.
Of course, as of right now, this is merely speculation in the comments sections, and although at first glance, it appears that Ricoh has rehoused the Sigma, I’m not convinced that is the case. I think that this is more than likely an original lens from Ricoh, which Pentax shooters should be very happy about.”
Via Fstoppers