Originally posted by Quark The focus hold setting was set to low.
The focus hold setting should be set to OFF when subject are moving in the Z direction, otherwise K1 AF tracks better across the frame but slows down in the Z direction, that's to prevent the camera to refocus on objects that come into the focus plane of the subject. That matches what Adam wrote.
Originally posted by Quark Pentax 300mm f4 DA* lens with aperture set at F/4 (for shallow depth of field)
The DA300 is not very good for tracking, especially when the subject comes near the camera, the SDM AF of the DA300 is too slow to catch up at near focus distances. DFA150-450 works way better for AF tracking.
There, for sure, can be cameras with better AF tracking, D5 or 1Dx. Regarding camera such as 5DIII, 5Dsr, D750,D610,6D.... the difference of AF may not be much to justify switching systems, especially for getting a successful bike test. For the occasional shooting of races, aircrafts, and bird inflight, I get good results from my K3 and K1, and I'm not going to switch to Nikon or Canon for a bike test (although I'm rather impressed by the keeper rate I get on a "bike test").
I did the bike test to try to comply with DPR, but... this was the first time in my life I have to shot bikes coming at me up to a few meters away. I previously shot race bikes but I would stand so close to get hit by a bike for the sake of being able to do the "DPR AF test".
How to say it? Are tests that you never use in your shooting any relevant for the choice of a camera system???
The DPR test is more about building a bad reputation than it is actually useful in the field. The proof is written by yourself: before the DPR test you where happy with the camera, and now that you did the DPR test you're not happy anymore. What it says: the camera is fine for you, but DPR review make you discontent of the system you were satisfied with. In the meantime, DPReview makes money out of the clicks they record from their website, and users like you may spend more money to switch to another system that you actually did not need.