[Newtophotos]

Is the K-5 significantly worse than the K-30 in terms of autofocus? Is it only worse in certain situations (low-light, with certain lens, etc.) I read in reviews when the K-30 came out that it's autofocus would be better (possibly due to focus peaking?) than the K-5, which was two years older at the time. Maybe this has been addressed by firmware updates and now both are comparable?

[jatrax]

Is the K-5 significantly worse than the K-30 in terms of autofocus?

The short answer is 'no'. For most people, in most situations, for taking most pictures I doubt you can find any significant difference. In some specific circumstances the k-5 is supposed to not focus as well. I've used k-5 for two years and never had any situation where I considered the AF to be a problem. However, most of the complaints were about low light particularly lit by tungsten bulbs, such as a dim bar or restaurant. I don't shoot in those conditions so maybe that's why it has not been an issue for me.

(possibly due to focus peaking?)

Focus peaking is irrelevant to how the auto focus works, it just shows you on the Live view screen an indication of what is in focus, mostly useful for manual focus and only with Live View.

Maybe this has been addressed by firmware updates and now both are comparable?

There have been firmware updates to the k-5, but fundamentally they use a different version of the AF system. K-5 uses SAFOX IX+ and k-30 uses SAFOX IXi+.

[Adam]

Is the K-5 significantly worse than the K-30 in terms of autofocus? Is it only worse in certain situations (low-light, with certain lens, etc.) I read in reviews when the K-30 came out that it's autofocus would be better (possibly due to focus peaking?) than the K-5, which was two years older at the time. Maybe this has been addressed by firmware updates and now both are comparable?

The K-30's live view AF is significantly better, but the phase detect AF is actually about the same, if not slightly worse. Tests have been conducted here:

Pentax K-30 Review - Autofocus Tests - PentaxForums.com

[atarget]

most of the complaints were about low light particularly lit by tungsten bulbs, such as a dim bar or restaurant. I don't shoot in those conditions so maybe that's why it has not been an issue for me.

.

Personally, I would not bring an expensive dslr to the bar. I'd take like Sammy NX1000, maybe...... and it's perfect in low light.

[Class A]

The K-30's live view AF is significantly better, but the phase detect AF is actually about the same, if not slightly worse.

I'd be extremely cautious with such conclusions, given how the tests were done.

It appears that a lot of the test were dependent on an exact alignment of the AF areas with the markings of the focusing screen. Maybe the tested K-30 was a bit lacking in that respect and hence missed many intended targets.

From the report

...every time the K-30's PDAF missed the target, it instead focused on the more contrasty edge of the printer's paper tray, slightly below and to the left of the Canon logo. So, the bad news is that the target we wanted wasn't in focus eight times out of nine;

So maybe the tester and camera just disagreed about what to focus on (same regarding the Russian doll tests). The K-30 AF could still be better in terms of accuracy. I'd be extremely surprised if it wasn't, particularly in low light.

[Adam]

I'd be extremely cautious with such conclusions, given how the tests were done.

It appears that a lot of the test were dependent on an exact alignment of the AF areas with the markings of the focusing screen. Maybe the tested K-30 was a bit lacking in that respect and hence missed many intended targets.

From the report

...every time the K-30's PDAF missed the target, it instead focused on the more contrasty edge of the printer's paper tray, slightly below and to the left of the Canon logo. So, the bad news is that the target we wanted wasn't in focus eight times out of nine;

So maybe the tester and camera just disagreed about what to focus on (same regarding the Russian doll tests). The K-30 AF could still be better in terms of accuracy. I'd be extremely surprised if it wasn't, particularly in low light.

As far as I recall, the reviewer who wrote that was particularly meticulous. There is of course no perfect way of conducting tests such as these, as you'd basically need to feed the camera's AF algorithm a virtual image and see how it reacts...

However, I do think that the results are 100% sound as far as AF speed is concerned. I compared the K-50 to the K-5 II here and there was no question that the newer CDAF is faster (and the same goes for the newer PDAF in the K-5 II):
Pentax K-50 Review - Autofocus - PentaxForums.com