K-r Autofocus performance update..not good

Started Nov 26, 2011 | Discussions thread
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Barry Fitzgerald
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K-r Autofocus performance update..not good
Nov 26, 2011

I'll just add before this post I was puzzled by the complaints about AF on this forum.

However today I shot some portraits in a low light environment lit with artificial light.

Out of the shots I took with phase detect AF I would estimate at least 60-70% missed AF, and by some margin in many cases despite AF confirm.

The camera displays no obvious problems in better light. Neither lens used shows any symptoms of AF issues in better light. Both the 90mm macro and 17-50mm showed serious AF problems in low light.

I can only conclude there is a serious issue with the low light AF performance of the K-r esp in some lighting conditions.

I noted the problem fairly quickly and switched to contrast AF live view. I worked around the issue, but I simply cannot afford to lose so many shots with an AF system that is as poor as this in low light. My Km5d is no champ for AF..in good light the K-r whips it and by a big margin. However I've never seen this number off missed AF shots from a camera before even the KM which could miss of course just like any camera, and it's not fast. But it's hit rate if far far higher than this, despite being a dated 2005 body.

As per another post I'm aware the central AF point is quite a bit larger than indicated and I attempted to compensate for this. But in most cases this didn't work. No degree of AF adjustment seems to work, it can hit AF once in a while! The odd time that is..but

I simply cannot afford to lose this number of shots for jobs like this. This was only a web job for a site so I'm not going to print, I might be able to focus magic a few if needed, but if I can't rely on the phase detect in low light it's an instant problem for me.

Question is this..

If it takes a K-5 to solve the problem I'll go that route and work around the issue in the for the time being and my Konica Minolta body is still in service and reliable, but I need honest feedback on this. If not then as I'm not heavily invested in Pentax and I have other options...

Very disappointing as the K-r is in many ways a great body lots of bang per buck. It's a huge let down to have this kind of issue. Maybe I should have stuck with the K-x because I never noticed this with that body.

As it is the K-r is not fit for purpose for low light shooting even my Fuji compact would kill it stone dead. Damn shame

Pentax K-5 Pentax K-m (K2000) Pentax K-r Pentax K-x
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