>>4447508>>4447530Really, it's a problem at low ISO.
The accelerator chip is said to actually be doing work at low ISO to improve tonality and dynamic range. My guess is they're using the green pixels to drive the signal of the red and blue pixels (red + blue = magenta). Essentially a bit of pre-bayering.
>>4447538First, your link about adapter doesn't compare keeper rates between the adapter on a Sony vs. the K1/ii. It does demonstrate that the lenses are way faster on the K1ii than on the Sony (probably not Sony's fault, just the adapter doesn't perform at a native level).
One of those links is about the 77mm, the one with the hit rates. That's a very slow lens, using screw mount and old 90s tech. It's known to be less accurate. Screw drives have the tendency to back and front focus because of inherent inaccuracy (they overshoot, or the algorithm underestimates how much it should drive).
On the other link about the k->e adapter, you can see the 28-105 is way faster at autofocus.
Generally the non-screwdrive lenses (ie. SDM, DC, and PLM lenses) do way better.
In practice, I haven't noticed any difference in autofocus performance/accuracy and hit rate between Canon and Pentax. And the Pentax does a lot better in low light than when I used to use older Sony mirrorless. But I also mostly shoot street, not sports or high action which is Pentax's weak point, especially the tracking algorithm (with the K3iii only just catching up to Nikon D500 performance).
But Pentax AF isn't as bad as people say it is, inherently. Just Pentax still markets a lot of screwdrive lenses, and people judge it by that. And those ARE worse at autofocus. (Either that, or they're recalling like 2005 era Pentax or even film era Pentax).
