Completely Dejected (auto focus K5)

I've read the article and I'm not so sure it isn't techno-nonsense, purposrting to be highly scientific but actually pretty meaningless.
If we subtract their 20 suggested error from the results and measure at 0 EV there's hardly any error at all. If we have a light level of 0.5 EV there isn't a problem.

Who routinely uses AF at such low light levels and why? Our eyes can't properly focus the camera when it's that dull....

Calibrating the AF in such dull light will not be accurate and will definitely lead to focusing errors.

Thank the Lord for Manual focussing. I think the issues outlined in the report would be the last reason ever to switch brands. The K-5 excels in all other respects.

How dark is 0.5 EV? Are we talking 'too dark to be able to walk around without bumping into things'? Dimmish room in the evening?

Well to be fair, if you can't see to focus, the AF is all there is.

There are loads of times it's too dark to see properly when I'd still like to be able to take pictures and rely on the AF.

I am not taking that dark! I'm on about in my kitchen with all the lights on!!

Ok, so I've now found this wiki article. Is it all nominally at 100 ISO?

You can see from the table that EV 0.5 is pretty dark. It is normally measured referencing ISO100 and an f1.4 lens.

The point is if there's no light, the image will be rubbish anyway, if there is light then it won't be EV0.5

It was noted in the article quoted that it would apply equally well to other marques, if there was a problem, although I haven't found a problem personally so it's hard to judge absolutely.

I don't know why you are assuming I was focusing in the dark!

first time I've heard of this .... something I might have liked to have encountered before I bought mine

"In the dark" is relative...the problem quoted is related to very low light levels.

I don't see what the big hoo-ha is with this focus and tungsten light problem, its not just limited to Pentax Cameras.

We have to adjust focus for infra red because its beyond our visible colour spectrum, so surely if a device is calibrated to focus on a particular temperature of light then anything either side may be off slightly, though not to the same degree as IR, and if your shooting wide open with very limited depth of field its only going to show even more???

Am I talking rubbish or is there some science behind that?

fatspider has a fair point.

Surely a camera that has various white balance settings, including tungsten, should be able to focus correctly in all those lighting conditions/temperatures .... and lets not forget it's not that long ago that this camera cost over £1000 at that price i'd expect it to be able to focus as well as anything out there.

Isn't this what the focus assist light is for???

For what it's worth, permanently switching to centre-point only solved all my AF problems (which were occasional and minor in the first place).

Subdued lighting in a living room, restaurant, dimmly lit kitchen, many live performances where you either can't use flash or don't want to, inside a dimmly lit church.

John