Thanks for starting the thread jpzk - I am most interested in learning how others are using the K3 AF settings.
I have used my trusty K5 over the past few years to shoot my kids playing junior basketball and while I have managed to get 100's of treasured shots but there have been many hundreds more that have been trashed due to focus not being right (or close to right). The K3 promised a significant upgrade in AF capability and, in summary, I am very pleased to find a big increase in "in-focus" shots. How much better? Subjectively, I guess that with my K5 (& DA*50-135mm) I would get about 25-50% acceptable focus whereas the K3 produces 75%+ acceptable and about half of these really sharp. The other noticeable improvement is that the "18. AF Hold status" also works a treat at basketball producing more potential "keepers".
With IQ, I initially thought the images were a lot grainier but I now think it is not so bad as I am cropping more heavily than previously and bringing out more grain. So probably there is a bit more noise than the K5. Overall though I am getting many more "keepers" and for my shooting the K3 is a definite step-up in technology over the K5.
I couldn't say if the DA*50-135 focusses more quickly on the K3 than the K5 - there are too many other AF variables that have also changed moving to the K3. The K3 tracking has no problem locking onto a player running towards the camera and holding the focus for the length of the court (and also having other players & the ref passing between the camera and the subject and keeping focus!). I read many comments on the forums that the DA*50-135 is the slowest focussing Pentax lens and not recommended for action/sports but I have found it performs quite well!!?? I purchased it specifically for basketball because it is F2.8 (basketball is fast action in usually poorly lit stadiums) and the zoom range ideal for sideline shooting (most shots I take would be around 70mm). I suspect that the long focus travel between 1m -infinity is slow but within the range it is very quick, ie if you are near to focus at the start it is very quick to lock on and can easily follow a player running full speed towards you. I think the inability of the K5 to track well has not helped the reputation of this lens. There are probably other lenses that are quicker but my view is that 50-135 can do a good job.
I photographed 7 matches at the Dandenong/Eltham junior basketball tournament over the Australia Day long weekend in January (this tournament is purportedly the worlds largest junior basketball tournament with over 1100 teams playing more than 7000 matches over the weekend!). I took about 1700 shots over the weekend and as my initial AF settings seemed to be working well, I did not change them much over the weekend.
My settings and comments are:
Exposure program - I use TAv - control the shutter and aperture to minimise the ISO - there is never too much light shooting basketball!
Aperture - F2.8 mostly to keep ISO as low as possible (increased to F3.5 if light was better but to be honest, with this lens I do not notice any difference in IQ)
Shutter - the boys are 15/16 years old and move pretty fast so 1/320 is a minimum, 1/250 works but you can expect some motion blur on hands & the ball
AFC
Use the AF back button
16. 1st Frame=3, in-focus priority (I think it is better to get the focus right at the start of the sequence and if it focuses on the wrong subject then you have the chance to repress the AF button/shutter)
17. Action in AFC = 1, Focus priority
18. Hold status = 3, Medium. This works really well - a major improvement in stopping the camera re-focussing on the wrong subject. I had a number of instances where the referee passes between the player and camera, obliterating 25% of the frame but the player remains in focus!
Expanded area Sel 3, with the initial focus point in the centre. This seemed to be working and I did not really try other settings. Maybe Sel 2 is worth a try??
Continuous shooting - High
All taken with firmware1.01 - v1.02 has reportedly further improved the AFC.
My general technique is to:
Target the player's chest (in portrait and showing feet, head, hands and usually the ring)
Hit the AF button and hold, the camera acknowledges focus point in the viewfinder (and ping).
Follow/track the player keeping the focus area centred in the viewfinder and take the shots when you think they will be best.
Repress AF is focus point is lost.
Crop image later to recompose.
Some examples from the tournament are posted below. All taken with K3 & DA*50-135F2.8 and have been PP'd in LR5 - cropping, exposure adjust, sharpening and NR.
I have included the first two to show the cropability of the images - the crop is about 100%
The last image shows a player running towards the camera - the focus is maintained through the sequence and this was the best composed shot of the 6 taken