[schnur07]

I currently have the Pentax KP paired with the Sigma 70-200mm HSM II. I take photos of kids soccer games and also cross country. I only have experience with this setup but the autofocus doesn't seem that impressive especially in low light conditions - poor lit fields at night. I'm seriously considering getting a Nikon set up just for the sports photography. The D500 paired with the Nikon 70-200mm would cost me about $1800.

I'm wondering if the Pentax 70-200mm or the other Sigma lens would provide better autofocusing and a better image quality under low light?

thanks!

[kypfer]

If this is an f/2.8 lens it should be perfectly adequate … you're unlikely to get better performance from a different system.
I've got the "old" Sigma EX 70-200mm f/2.8 and it's very good on my KP (and all my other Pentax bodies!).

[schnur07]

If this is an f/2.8 lens it should be perfectly adequate … you're unlikely to get better performance from a different system.
I've got the "old" Sigma EX 70-200mm f/2.8 and it's very good on my KP (and all my other Pentax bodies!).

Yes it's an f/2.8 lens. One thing that is really frustrating is when I use continuous AF and then the frame rate goes way down.

[mikesbike]

I use continuous AF and then the frame rate goes way down.

Sounds like you are doing quite a lot of burst shooting.

[schnur07]

I decided it would be a good idea to really pay attention to what was going on with the camera tonight when I was shooting the soccer game. The really slow framerate happens when I have the focus button held down (back button focus) using continuous focus during low light under the stadium lights at night. Tonight I was shooting wide open at f2.8, shutter speed was 1/500 and ISO was at 128,000. So maybe that would push a lot of camera/lens combos to their limits under those conditions. When I was shooting earlier in the game when there was still daylight, the framerate was respectable.

[kypfer]

Yes it's an f/2.8 lens. One thing that is really frustrating is when I use continuous AF and then the frame rate goes way down.

It does … simply because the camera is re-checking the focus for each shot, also, at that sort of ISO, the camera will be doing all sorts of noise reduction, which could be turned off to see if the results are adequate.
Unfortunately you can't have every shot more or less in focus and hi-speed frame rates
If the action is across the frame rather than closer and farther you could try single focus rather than continuous.

Tonight I was shooting wide open at f2.8, shutter speed was 1/500 and ISO was at 128,000

Possibly time to develop your panning skills and try a slower shutter speed to bring the ISO down. A little bit of action blur can improve a sports shot
Another thing to try might be reducing the image size (do you really need 24Mpixel images?) … also assuming here you're shooting JPG and not RAW!

I'm thinking the problem isn't the lens, but the camera - I'd try switching that before swapping out the lens - maybe you do need a better lens, but you can decide that later.
Have you got the aperture set at 2.8? The smaller the aperture the harder it is for the KP to do autofocus.
The frame rate on the KP isn't that high to begin with, but shooting in burst mode will cause pauses as the thing struggles to get the data written to the card.
The K3 III has a slightly faster frame rate than D500, by the way, and the K3 II is roughly equivant. The K3 III and the D500 both support the newest SDXC UHS-ii cards, so the writing speed should be much faster than the KP or K3 ii.

[jgnfld]

Could you post the pics and exifs from a shot or 2?

[bdery]

Image quality from the Pentax will be noticeably better at F2.8, more or less even at F4 and beyond. AF will be better, but YMMV depending on the context. Nikon will do better for tracking, but for static AF-S Pentax is much better than its reputation. Even comparing the K-1 III of original K-3 with a modern Sony, AF-S isn't really different.

If you like your Pentax system, I would not hesitate to invest in good glass instead of looking over the fence.

Have you looked at the Pentax 70-200mm review? I compare it with the Tamron 70-200, it could give you some comparison points.

[schnur07]

It's been a long time since I've uploaded and attached photos. Let's hope this worked. Here's a sampling of various photos in low light conditions. They're nothing special but just want you to see some of the shots and get your continued feedback.

I really appreciate all of the advice. I can certainly shoot smaller sized photos since none of them are getting printed - I just put them on an Amazon photo link for players and families to look at and some make it into the yearbook I think. I'll have to look into the noise reduction thing as well.

This is one of great things about the internet is having a place where people from all over the planet can share their knowledge regarding a shared interest like Pentax photography. Thanks all!

[kypfer]

Here's a sampling of various photos in low light conditions. They're nothing special but just want you to see some of the shots and get your continued feedback.

Well, I don't see a noise problem
Remember, it's the camera that decides when an image is in focus so the shutter is released, any other lens of similar specification will likely give similar results on the same camera.
Yes, some lenses may have a physically faster autofocus mechanism, so the lens may achieve the same degree of focus faster, but the camera will decide when the image is sufficiently focussed to release the shutter, assuming you've got it configured to do so.

[schnur07]

I wonder if I should adjust some of the focus priority settings or the auto focus hold settings. I kind of switch back and forth between continuous AF and single AF. I'm not sure what my preference is. Maybe in low light, AFS would be the better option. And I'm sure I don't have very good technique. But it's a weird thing to try to get better at - not sure what I need to do to improve. It's not like practicing shooting a basketball where you get immediate feedback of whether you made the shot or not.

[mikesbike]

The K3 III has a slightly faster frame rate than D500, by the way, and the K3 II is roughly equivant. The K3 III and the D500 both support the newest SDXC UHS-ii cards, so the writing speed should be much faster than the KP or K3 ii.

This answer is similar to what I was going to bring up. The K-3 III was developed in good part with action shooting in mind. However, the results shown in the sample images presented seem very good.

---------- Post added 09-21-22 at 05:53 PM ----------

I wonder if I should adjust some of the focus priority settings or the auto focus hold settings. I kind of switch back and forth between continuous AF and single AF. I'm not sure what my preference is. Maybe in low light, AFS would be the better option. And I'm sure I don't have very good technique. But it's a weird thing to try to get better at - not sure what I need to do to improve. It's not like practicing shooting a basketball where you get immediate feedback of whether you made the shot or not.

Doing it often is certainly important for improving your technique and getting more keepers. I have done some indoor roller hockey at the college level and beyond. It took numerous events before I was able to get many keepers. By looking at my results, I began to realize what was important to convey the context of the game's action rather than just a shot of a particular player only.

I would say a fair percentage of the samples you have given here could be useful for the intended purpose. In my case, I generally used AF-S and worked on improving my panning, while also learning the game well enough to anticipate and react quickly enough when a shot would take place. I was constantly hitting the AF half-press of the shutter button. Another aspect to consider: for controlling the visual effect of portraying movement, there might be at certain times a benefit for regulating shutter speed at a somewhat slower level- enough so some parts of the action will be sharp while other parts will portray movement. For example, a foot might look lightly blurred, as well as the ball emerging from it, while the main figure still remains sharp. This takes a bit of experimenting, as various sports entail different degrees of speed and specific movements.

[kypfer]

I wonder if I should adjust some of the focus priority settings or the auto focus hold settings. I kind of switch back and forth between continuous AF and single AF. I'm not sure what my preference is. Maybe in low light, AFS would be the better option. And I'm sure I don't have very good technique. But it's a weird thing to try to get better at - not sure what I need to do to improve. It's not like practicing shooting a basketball where you get immediate feedback of whether you made the shot or not.

As with "birds-in-flight", one of my interests, it's all down to practice.
I've taken very many dozens of "generic seagull" pictures, in all sorts of lighting, wind and weather conditions, simply to get so familiar with my rig that when that once-in-a-season whatever flies past I've got a reasonable chance of getting it.
Don't just take pictures of games you're interested in, take every opportunity to take pictures of similar events in similar lighting so you've got more material to analyse and can then decide what are the best settings for you!
Take sequences shots of suitable subjects at the various options available … A/F Hold, AF-S, AF-C etc. etc., make notes of what and which, then sit down at the computer and simply decide which settings suit you the best.
It's likely to take several sessions to start to see a pattern, but eventually (hopefully) you'll start to see a preference for a particular configuration … that's the one you can fine tune
Store it as a User Mode, so you always start from exactly the same settings, then if there's a further trend to a slightly higher shutter speed, a slightly different aperture or whatever it'll become obvious quite quickly and you can then modify your User Mode to suit.
I made the effort a few winters ago to diligently work through several years worth of exposures, making notes (from the EXIF) of the settings the camera had for exposures I was happy with, and when it was all plotted out 1/1500 @ f/8 auto-ISO (TAv Mode) became the obvious choice.
This is for me, using my "bigma" handheld, and I'll freely wind the shutter speed up or down or adjust the backlight compensation to suit individual circumstances, but I know where I'm starting from and that takes a lot of the guesswork out of it
Good luck

[schnur07]

I'm considering upgrading to the K3 III, but holy crap it's expensive. From what I've read the AF on it is much better, higher frame rate and does better in low light. Anybody have experience with the K3 III vs the KP?