http://forums.dpreview.com/forums/read.asp?forum=1036&message=38366802
http://forums.dpreview.com/forums/read.asp?forum=1036&message=38365268
Test photos are posted and the following is quoted from one of the K-5 users above:-
"I bought a K-5 which was clearly having trouble with AF in tungsten light. Focus worked fine in daylight, so I loaded v1.03 and did some testing. Unfortunately the new firmware didn't help.
I know some people have a K-5 that works in tungsten light, but I decided to give up for now and returned the camera.For those who can't be bothered to look, tungsten AF on both older cameras outperformed the K-5 by a margin that doesn't require pixel peeping to spot."
Well, it seems that the low light tungsten Front Focusing issue is a real and newly introduced one with Pentax latest AF system of the SAFOX IX, which used in the K-5 and K-r. Too bad.. >:-(
All Related:-
http://ricehigh.blogspot.com/search?q=SAFOX+IX