AF on K-7 Vs K20D

Ignoring the speed of the AF between both cameras, I am talking about the accuracy.
Is the AF on the K-7 better than the K20D?
I ask as I have intermittent problems with the AF on the K20D. It does not matter which lens is on, but having said that it is only 3 that really have the problem. I have used the AF adjust but to no avail. Having said that, sometimes the lens is spot on, others it is way out. No problems though with the lenses on the DS, but still very occasional issues on the K10D.
So My question is, the K-7, is it more reliable? Please only answer if you have or used both a lot.

The only time I have focusing problems with my K20D is when light and/or contrast are low. In such situations, the K-7 is improved, especially under tungsten/artificial lights.

I've just been doing some comparisons between my K20D and a K-7 and found no significant differences, even in low light (before the focus assist light on the K-7 come on).

What lenses have the issue? If they are screw drive, the symptom can often be caused by backlash in the drive system, and depending which direction the rotation is coming from, you can get a different focus point.

Another thing to bear in mind is that the AF points have a much wider coverage than just the focus dot coverage and if you have several objects at different distances in the AF point area (especially with a wide angle lens) the AF cannot decide which object to focus on and either focusses on the wrong one or gives up completely.

A mix I am afraid Richard

The ones it really happens on are as follows:-
SMC-DA* 50-135 F2.8
Sigma 24-70mm F2.8
Tokina 20-35mm F2.8

Plus, very occasionally
SMC-FA 50mm F1.4
Sigma 105mm Macro
Sigma 55-200mm DC

Like I said, it is not all the time, but only on occasion, but when it happens it is not good, especially as you only have one chance to take the image.

Strange though, my 16-45 has never had the problem (touch wood) only the ones stated, and it varies between close and general focus.

The only body that never does it, is the istDS but 6MP is not what I need for these instances.


Hmmmm, a strange one.

Well, my k20 needed some AF adjust, and went hunting in low-light... It also had a specific problem with my tamron 70-200 2.8 where it couldn't snap out of close focus : once there, it just did a little focus move on each half-press, but nothing else... I had to either switch to MF, or focus on something nearby, to make it responsive again...

Now, I noticed that the focus sensors are tricky... The center point, for instance, is in fact extending well below the red square, and if what you're focusing onto has a more "contrasty" edge in this area, then that's where it will focus...

The K7 is generally faster (test done with two FA50, focused at the same time), much more responsive in low-light, and locks faster (less hunting around).
It needed no AF adjust, but the sensors are still tricky!

Sorry Guys,

No real help as I am just intending to buy a K7................


Regards


Paul

A second thought is to 'clean' the contacts. I have noticed that this does improve the Af function on both my K10 bodies.

Seconds to do.

Regards


Paul

Don't know if I really see any difference, but there was really quite a lot of dirt coming of the contacts. I just took a cotton swab with some alcohol to clean them.

Cleaned them no change hmmmmmmmmmm