Pentax KP Continous focus test

08amczb · 03-08-2017, 12:06 AM

I will repeat the test in focus priority with different focus point selection modes when the weather and my time allows it. I'am waiting for bright sunlight, when I'am home. I hope I can do it on sutarday.

Tatouzou · 03-08-2017, 08:12 AM

Originally posted by apete

I have only K5ii which is much older generation but - from what I have observed - once focus priority is selected FPS is always reduced dramatically. This setting may be a game changer. Would you be able to repeat the test in focus priority mode?

Though still I think your effort was one of the best of all I have seen. Thanks for that!

K3 has much improved AF-C over K5, quite good in the Z axis (select a single AF point and track the target by panning the camera), but disappointing in X and Y tracking (SEL9 or SEL25).

**bobbotron** · 03-10-2017, 12:51 PM

Originally posted by 08amczb

I will repeat the test in focus priority with different focus point selection modes when the weather and my time allows it. I'am waiting for bright sunlight, when I'am home. I hope I can do it on sutarday.

Hey, the camera has good high ISO, why not set it to 1600 or 3200 for some of your tests?

Btw, have you checked the calibration of your lenses on the KP?

08amczb · 03-10-2017, 02:56 PM

Originally posted by bobbotron

Hey, the camera has good high ISO, why not set it to 1600 or 3200 for some of your tests?

The good high ISO performance doesen't help the AF system in the dark. I am courios about the capabilities in good light first.

Originally posted by bobbotron

Btw, have you checked the calibration of your lenses on the KP?

Now I did it. The 50-135 does not need any calibration, nor the 55-300PLM so my tests were valid as I tought. I was supprised by my 16-50, it needs -2 and I didn't noticed it on my K-30. The F 50 F1.7 needs the same -6 and the 10-17 now need -2. The others are fine. I hope tomorrow I experience the same accuracy in sunlight.

**bobbotron** · 03-10-2017, 03:11 PM

Originally posted by 08amczb

The good high ISO performance doesen't help the AF system in the dark. I am courios about the capabilities in good light first.

Now I did it. The 50-135 does not need any calibration, nor the 55-300PLM so my tests were valid as I tought. I was supprised by my 16-50, it needs -2 and I didn't noticed it on my K-30. The F 50 F1.7 needs the same -6 and the 10-17 now need -2. The others are fine. I hope tomorrow I experience the same accuracy in sunlight.

For sure. My suggestion was for daylight (at least, that was the intent of my suggestion.) :P It is my experience if you want to freeze action, bumping your ISO to at least 400 (even on bright days!) ensures your camera isn't going to pick poor exposure settings for the job. Aperture priority, f5.6 or f8, 400 ISO. (Clearly, this is all just my opinion!)

08amczb · 03-11-2017, 09:48 AM - **1 Like**

I've done some more testing, see my first post, I've edited it to include all new findings.
Now I'am satisfied with the af system, t can do 3D tracking. I think,now Pentax is competitive on the market in all respects again, not just in performance/price.

**bobbotron** · 03-11-2017, 10:02 AM

Thanks for posting an update, nice results!

apete · 03-11-2017, 01:28 PM

Thanks a lot for new tests! While waiting for my KP to arrive it is really nice to read positive reviews :-)

FantasticMrFox · 03-11-2017, 02:46 PM

Originally posted by Tatouzou

K3 has much improved AF-C over K5, quite good in the Z axis (select a single AF point and track the target by panning the camera), but disappointing in X and Y tracking (SEL9 or SEL25).

From my experience it's quite the opposite, z-axis tracking is what the K3 is worst at. With subjects moving directly towards or away from the camera it can't even properly keep up with someone moving at normal walking pace.

**mikesbike** · 03-11-2017, 07:19 PM

I do shoot some action, including fast-action club roller-hockey. I've been using my K-5 IIs, which I have noticed has better AF than my previous K-5. I seldom do burst shooting. My friend being a goalie helps, so I can mainly focus on him, then switch just slightly to other incoming action. I just keep hitting the half-press and fire when I think I can nail the shot I want. I have been successful to a very large extent, being quick on the trigger. I come from years of manual focus, and I am still grateful to have any AF! I too have found the lens used makes a difference. For this purpose I use an older model f/2.8 constant aperture short zoom lens, the Sigma AF 24-60mm EX DG which uses the good old camera screw-drive, but it seems very quick. Everything else being equal, it seems having the f/2.8 lens letting more light come in, also allows the camera's AF system to perform better than a similar slow aperture lens. For this kind of assignment, I shoot wide open so I can get my shutter speed up to around 1/500 sec at least, with ISO at 2,000-2,500 for the indoor lighting I encounter.

I agree that the DA* 50-135mm f/2.8 is a slower focussing lens, though a very good lens. I also have the DA* 200mm f/2.8 prime lens, and I believe it to have faster AF, though both use the older SDM focus motor. I also agree that the DA 18-135mm DC WR has one of the quickest and most sure AF, which is surprising. I also have the DA 55-300mm f/4-5.8 WR which uses the old screw driven AF. I think the main reason it is considered of slower AF is because it has a longer focus throw. If the moving subject stays at some distance, then the lens doesn't have to move focus very far and it does ok. The advantage of longer focus throw is in more accurate manual focus fine-tuning. Reports indicate some improvement for faster AF in the new 55-300 lens, but not dramatically so. And typical for Pentax, in trying to make the lens more compact, it is of slower aperture. My 55-300mm f/4-5.8 HD WR can keep to f/4 up to 100mm and to f/4.5 all the way out to 200mm for higher shutter speed/lower ISO. So it comes close to the big, expensive 70-200mm f/2.8 lenses by about one stop, while having greater range going from 55mm, with its performance in this range being of very good quality indeed. I am not in any way dissatisfied with this lens! I wonder where the new lens is wide open to 100mm, and out to 200mm?

08amczb · 03-12-2017, 04:01 AM

The new 55-300 PLM is F4.5 from 55mm to 150mm and F5.6 from 150mm to 300mm. Only at 300mm it's F6.3. I have the red ring WR and the new one also and I feel the AF is significantly faster and more accurate. It does not hesitating any.
With the K-30 I prefocused and shot a burst and hoped one sharp image. In bright sunlight it was better, but I wasn't satisfied with the AF. I doesn't have that much experience with manual focus lenses and my eyes arn't perfect, so I appreciate I can trust the KP's AF system.

03-11-2017, 07:19 PM	#25
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,549	I do shoot some action, including fast-action club roller-hockey. I've been using my K-5 IIs, which I have noticed has better AF than my previous K-5. I seldom do burst shooting. My friend being a goalie helps, so I can mainly focus on him, then switch just slightly to other incoming action. I just keep hitting the half-press and fire when I think I can nail the shot I want. I have been successful to a very large extent, being quick on the trigger. I come from years of manual focus, and I am still grateful to have any AF! I too have found the lens used makes a difference. For this purpose I use an older model f/2.8 constant aperture short zoom lens, the Sigma AF 24-60mm EX DG which uses the good old camera screw-drive, but it seems very quick. Everything else being equal, it seems having the f/2.8 lens letting more light come in, also allows the camera's AF system to perform better than a similar slow aperture lens. For this kind of assignment, I shoot wide open so I can get my shutter speed up to around 1/500 sec at least, with ISO at 2,000-2,500 for the indoor lighting I encounter. I agree that the DA* 50-135mm f/2.8 is a slower focussing lens, though a very good lens. I also have the DA* 200mm f/2.8 prime lens, and I believe it to have faster AF, though both use the older SDM focus motor. I also agree that the DA 18-135mm DC WR has one of the quickest and most sure AF, which is surprising. I also have the DA 55-300mm f/4-5.8 WR which uses the old screw driven AF. I think the main reason it is considered of slower AF is because it has a longer focus throw. If the moving subject stays at some distance, then the lens doesn't have to move focus very far and it does ok. The advantage of longer focus throw is in more accurate manual focus fine-tuning. Reports indicate some improvement for faster AF in the new 55-300 lens, but not dramatically so. And typical for Pentax, in trying to make the lens more compact, it is of slower aperture. My 55-300mm f/4-5.8 HD WR can keep to f/4 up to 100mm and to f/4.5 all the way out to 200mm for higher shutter speed/lower ISO. So it comes close to the big, expensive 70-200mm f/2.8 lenses by about one stop, while having greater range going from 55mm, with its performance in this range being of very good quality indeed. I am not in any way dissatisfied with this lens! I wonder where the new lens is wide open to 100mm, and out to 200mm? Last edited by mikesbike; 03-11-2017 at 07:25 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Please test electronic shutter on KP	beholder3	Pentax KP	37	12-18-2020 11:47 AM
Changing focus point on Pentax KP	NuDrake	Pentax KP	21	03-04-2017 12:51 PM
More test images from the Pentax KP compare with D500/K1	melander	Pentax KP	3	02-02-2017 11:00 PM
Focus test feedback	thehiko	Pentax K-3 & K-3 II	10	10-22-2015 05:44 AM
K-5 Continous focus in bad lighting sports example	Urkeldaedalus	Pentax K-5 & K-5 II	4	12-04-2010 06:58 PM

03-08-2017, 12:06 AM	#16
08amczb Veteran Member Join Date: Dec 2013 Posts: 796 Original Poster	I will repeat the test in focus priority with different focus point selection modes when the weather and my time allows it. I'am waiting for bright sunlight, when I'am home. I hope I can do it on sutarday.

03-08-2017, 08:12 AM	#17
Tatouzou Senior Member Join Date: Feb 2015 Posts: 175	Originally posted by apete I have only K5ii which is much older generation but - from what I have observed - once focus priority is selected FPS is always reduced dramatically. This setting may be a game changer. Would you be able to repeat the test in focus priority mode? Though still I think your effort was one of the best of all I have seen. Thanks for that! K3 has much improved AF-C over K5, quite good in the Z axis (select a single AF point and track the target by panning the camera), but disappointing in X and Y tracking (SEL9 or SEL25).

03-10-2017, 12:51 PM	#18
bobbotron Site Supporter Join Date: Jan 2015 Location: Ottawa, ON Photos: Gallery Posts: 3,349	Originally posted by 08amczb I will repeat the test in focus priority with different focus point selection modes when the weather and my time allows it. I'am waiting for bright sunlight, when I'am home. I hope I can do it on sutarday. Hey, the camera has good high ISO, why not set it to 1600 or 3200 for some of your tests? Btw, have you checked the calibration of your lenses on the KP?

03-10-2017, 02:56 PM	#19
08amczb Veteran Member Join Date: Dec 2013 Posts: 796 Original Poster	Originally posted by bobbotron Hey, the camera has good high ISO, why not set it to 1600 or 3200 for some of your tests? The good high ISO performance doesen't help the AF system in the dark. I am courios about the capabilities in good light first. Originally posted by bobbotron Btw, have you checked the calibration of your lenses on the KP? Now I did it. The 50-135 does not need any calibration, nor the 55-300PLM so my tests were valid as I tought. I was supprised by my 16-50, it needs -2 and I didn't noticed it on my K-30. The F 50 F1.7 needs the same -6 and the 10-17 now need -2. The others are fine. I hope tomorrow I experience the same accuracy in sunlight.

03-10-2017, 03:11 PM	#20
bobbotron Site Supporter Join Date: Jan 2015 Location: Ottawa, ON Photos: Gallery Posts: 3,349	Originally posted by 08amczb The good high ISO performance doesen't help the AF system in the dark. I am courios about the capabilities in good light first. Now I did it. The 50-135 does not need any calibration, nor the 55-300PLM so my tests were valid as I tought. I was supprised by my 16-50, it needs -2 and I didn't noticed it on my K-30. The F 50 F1.7 needs the same -6 and the 10-17 now need -2. The others are fine. I hope tomorrow I experience the same accuracy in sunlight. For sure. My suggestion was for daylight (at least, that was the intent of my suggestion.) :P It is my experience if you want to freeze action, bumping your ISO to at least 400 (even on bright days!) ensures your camera isn't going to pick poor exposure settings for the job. Aperture priority, f5.6 or f8, 400 ISO. (Clearly, this is all just my opinion!)

03-11-2017, 09:48 AM - 1 Like	#21
08amczb Veteran Member Join Date: Dec 2013 Posts: 796 Original Poster	I've done some more testing, see my first post, I've edited it to include all new findings. Now I'am satisfied with the af system, t can do 3D tracking. I think,now Pentax is competitive on the market in all respects again, not just in performance/price.

03-11-2017, 10:02 AM	#22
bobbotron Site Supporter Join Date: Jan 2015 Location: Ottawa, ON Photos: Gallery Posts: 3,349	Thanks for posting an update, nice results!

03-11-2017, 01:28 PM	#23
apete Senior Member Join Date: May 2014 Posts: 249	Thanks a lot for new tests! While waiting for my KP to arrive it is really nice to read positive reviews :-)

03-11-2017, 02:46 PM	#24
FantasticMrFox Veteran Member Join Date: Oct 2014 Location: Munich Posts: 2,339	Originally posted by Tatouzou K3 has much improved AF-C over K5, quite good in the Z axis (select a single AF point and track the target by panning the camera), but disappointing in X and Y tracking (SEL9 or SEL25). From my experience it's quite the opposite, z-axis tracking is what the K3 is worst at. With subjects moving directly towards or away from the camera it can't even properly keep up with someone moving at normal walking pace.

03-12-2017, 04:01 AM	#26
08amczb Veteran Member Join Date: Dec 2013 Posts: 796 Original Poster	The new 55-300 PLM is F4.5 from 55mm to 150mm and F5.6 from 150mm to 300mm. Only at 300mm it's F6.3. I have the red ring WR and the new one also and I feel the AF is significantly faster and more accurate. It does not hesitating any. With the K-30 I prefocused and shot a burst and hoped one sharp image. In bright sunlight it was better, but I wasn't satisfied with the AF. I doesn't have that much experience with manual focus lenses and my eyes arn't perfect, so I appreciate I can trust the KP's AF system.