Which autofocus setting

[djteknovibe]

I never normally ever take photos of moving objects and in fact i've probably only photographed about 5 moving objects in the past 10 years, I think you use autofocus continuous don't you? Does anyone know which is best either using autofocus continuous or burst mode? I always use burst mode anyway with 99% of things I photography unless it's a low light landscape in which case I always use a tripod and remote control with single shot mode.

[richandfleur]

I've recently had great success with tracking the kids at sports, using AF-C and Auto 5 point AF mode, using F8-9 on the Pentax 55-300mm zoom. IF my Pentax K-S1 had a bigger buffer for RAW files in burst mode, then I'd be pretty happy right now. A K-3 level speed and buffer would suit me fine.

[djteknovibe]

I did photograph a train last week going slowly with AF-C and it came out very sharp but yesterday I forgot to use AF-C. Plus seeing as I always use continuous burst mode for photographing anything except low light landscapes the photos came out ok but I wasn't sure which mode would be best because the kids were running about fast. In burst mode I take loads and then flick through them and pick out the sharpest. But I guess doing that isn't the best idea for movng subjects because the camera only focuses once and fires a burst wheras AF-C continually re-focuses the subject.

[scarr1]

try using back button focus, and leave just leave AF-C on all the time. single press = AF-S, constant press = AF-C.

[djteknovibe]

What's back button focus? My K70 doesn't have that.

[scarr1]

It does. If you look on the back, near where your thumb would rest, you have a button marked AF/AE-L. You need to go into the menu, look for button customisation and select AF2 ( i think). This disables the shutter button focus so auto focus is done by pressing the rear AF button.
Then select AF-C.
Try it...it may seem a bit odd at first, but i find it much better.

[djteknovibe]

I use that button anyway so...

[richandfleur]

I've never seriously given the back button AF a shot, but do get it's purpose.

Will be interesting to hear the preferred AF settings from others for continuous mode. I've opted for the centre 5 AF points, as when shooting sports with kids, if I went to the full AF autopoints options (11 on the K-30 / K-S1 cameras) then the camera almost always grabbed the background. AF 5 seemed to be the magic combo for me and continued to track with a half press. I've moaned about this for a long time but have had recent improved success with this combo.

Also having a large depth of field from around the F8-9 region helped by making the exact AF point less critical, and it also meant the lens was typically working in it's sharpness sweet spot too. This worked well for ideal lighting conditions. I always have a max cap of ISO 3200 on my cameras, but this still allowed a shutter speed of around 1/600 - 1/800s or so for sports. Sensor stabilisation turned on.

[Judderman62]

Once you switch to back button focus, and it took me a while to both understand and be convinced to try it, you will never go back. I use it even on my Canon Eos-m . It's the future

[richandfleur]

It's the future

Actually that is tracking AF, where you target an object of interest and the camera follows it around.

Worth noting that actually, in that the AF-C / Auto 5 point method I mention above fully does require you to keep the subject slap bang in the middle of the frame. Take it too far out off centre and it'll just leap to the background. Maybe the Auto 11 point would help with this if they're placed further out, but with that mode I've had problems targeting the point of interest initially. It's all a bit of a compromise, but I have however had many more keepers than ever before with this setup, enough to say I'm happy with it

To me Video is the remaining standout point to improve, but AF is definitely close by.

[djteknovibe]

I didn't get any better or sharper shots using the back AE-L button, I always use ISO200 outside and never any ISO higher than that because I HATE noise. I did try the 5 point AF and still I couldn't get any sharper shots than using the single point AF. Would you say the focus and image sharpness of this photo below is ok, average or good for the situation of photographing kids running about?

https://www.flickr.com/photos/dj_teknovibe/33810320906/

[richandfleur]

I'd say you've got motion blur going on.

ƒ/8.0
133.0 mm
1/160
200

No sure what mode you were in, but if it's one of the auto modes then it's going to slow the shutter speed down to let more light in.
Try the likes of TAv, where you can specify the f aperture of f8 but also bump the shutter speed up to say 1/640 or above. (Assuming you're after a perfectly frozen image with no motion blur).

General rule for handheld shutter speed should be fine, even more so if you have SR turned on, but that won't freeze motion in the photo.

Noise can be addressed, and if it's the difference between getting a shot and not then it's worth it. The K-70 should be good noise wise up to 1600 - 3200 range. You'd be hurting your ability to get fast moving shots by capping unnecessarily at ISO 200, unless you're looking to use a flash to assist.

[Derek897]

Your biggest problem there is shutter speed not focus.
You cant really expect sharp shots at that speed with an oncoming subject.
You really should be able to raise iso to 800 without any visible noise which will get your shutter speed closer to where it needs to be.
You could open the aperture a little too, if the shutter speed is still too low.

[djteknovibe]

I was using Aperteur Priority mode, I had it set to ISO200 because I hate image noise so I leave it on that for all day shots unless I absolutely cannot get a shutter speed I need then I use ISO400. On my K70 noise is noticeable at ISO1600 so I never use any higher than ISO400. It's not my lack of experience or knowledge it's my stubborness to have as little noise as possible I know I could get it sharp by using ISO1600.

[Derek897]

Iso 800 is a safe bet then or have you tried it.
Theres a huge difference between 200 or 400 and iso 1600