Autofocus on K3

TerryL · 01-12-2020, 05:54 AM

Is the autofocus on the K3 better than the KP? Thank you.

**aslyfox** · 01-12-2020, 06:37 AM

have you seen the KP in depth review yet -

Quote:

. . . AF Tracking Test

Moving subject tracking during burst shooting is a good scenario for stress-testing a DSLR's focusing system. To find out just how much the KP's tracking autofocus has been improved compared to the K-3 (and older bodies), and how well it fares overall, we performed a moving AF test similar to the one in our original K-3 review. As shown in the illustration below, a bicyclist rode past the camera along a semicircular track, thus changing both his horizontal and vertical distance at any given time.

KP vs K-3 autofocus test setup (camera hand-held)

The camera was set to continuous-high mode with focus priority set. We used two AF point modes: center-point and SEL-M (25 points). Each test was repeated 3 times; the summed result is presented below. We used the DA 18-135mm lens (set to 135mm) rather than the faster 55-300mm PLM in order to better expose any differences between the two cameras.

Our motivation for the AF mode selection was simple: center-point mode allows the camera to concentrate on focusing speed and accuracy alone, while the SEL-M mode shows us how well the camera can do both at the same time.

Center Point
Select-M
Pentax KP 92%
(46/50) 83%
(43/52)
Pentax K-3 62%
(32/52) 59%
(30/51)
In-focus photo rate (sharp photos / total photos)

The results show that while both cameras sustained roughly the same framerate, the KP outperformed the K-3 handsomely regarding AF. What's more impressive is that these cameras differ solely in software tweaks to the AF system. The test also shows that the single point mode can provide a higher keeper rate than multi-point mode assuming it is feasible for the photographer to keep the selected point on the subject at all times.

Overall this shows that the KP is quite good for tracking, even without the fastest-focusing lens available. However, there is certainly room for improvement— the utility of the fancy multi-point mode is questionable as its focusing speed and accuracy falls noticeably short of center point mode. We previously performed this test with the Nikon D610 in 39-point tracking mode and captured 80 sharp photos, out of 82. While the KP can compete with this figure in single point mode, the competition's multi-point tracking is still comfortably ahead. . . .

Read more at: Pentax KP Review - Focusing | PentaxForums.com Reviews

TerryL · 01-12-2020, 06:43 AM

Originally posted by aslyfox

have you seen the KP in depth review yet -

Read more at: Pentax KP Review - Focusing | PentaxForums.com Reviews

That definitely answers my question. Thank you.

Alnjpn · 01-12-2020, 07:44 AM

I can comment on the K3 but not the KP. I have had the k3 for 3 years and have had ongoing AF problems. It is fast but most certainly NOT accurate. (This is through the viewfinder, accuracy in Live View is fine). I have tried adjusting the lenses and cleaning the Af module but still the problem persists. This may be a one off problem although I have seen similar comments on this forum. I have an old Canon 6D which I use for portraits. While the AF is much slower it is considerably more accurate and reliable. If AF accuracy is important you might wan't to avoid the K3

**aslyfox** · 01-12-2020, 07:53 AM

Originally posted by Alnjpn

I can comment on the K3 but not the KP. I have had the k3 for 3 years and have had ongoing AF problems. It is fast but most certainly NOT accurate. (This is through the viewfinder, accuracy in Live View is fine). I have tried adjusting the lenses and cleaning the Af module but still the problem persists. This may be a one off problem although I have seen similar comments on this forum. I have an old Canon 6D which I use for portraits. While the AF is much slower it is considerably more accurate and reliable. If AF accuracy is important you might wan't to avoid the K3

have you checked the adjustable diopter ?

some times that shifts on me and when I think I have a good focus I do not

**Madaboutpix** · 01-12-2020, 07:54 AM

K-3 user since 2014. Always running on the latest firmware. PDAF relatively fast and snappy, no inaccuracy problems with any of my Pentax DA lenses. The in-depth reviews will probably point out that the newer KP has improved AF, but that is only to be expected.

**microlight** · 01-12-2020, 09:19 AM

The K-3, K-3II and KP all use the same SAFOX 11 27-point AF module. However, the processing algorithms used were improved for the K-3II from the original K-3, and then improved again for the KP.

TerryL · 01-12-2020, 10:31 AM

The only reason I asked is I found a new K3 and am tempted to buy it.

---------- Post added 01-12-20 at 11:16 AM ----------

Originally posted by Alnjpn

I can comment on the K3 but not the KP. I have had the k3 for 3 years and have had ongoing AF problems. It is fast but most certainly NOT accurate. (This is through the viewfinder, accuracy in Live View is fine). I have tried adjusting the lenses and cleaning the Af module but still the problem persists. This may be a one off problem although I have seen similar comments on this forum. I have an old Canon 6D which I use for portraits. While the AF is much slower it is considerably more accurate and reliable. If AF accuracy is important you might wan't to avoid the K3

I had similar problems with my K1 mkIi. Every lens I own was out of focus. My K1 was perfect. So, I sent it to Precision to check. Boy, did I dread that.

01-12-2020, 05:54 AM	#1
TerryL Pentaxian Join Date: Jan 2018 Location: Virginia, USA Photos: Albums Posts: 850	Autofocus on K3 Is the autofocus on the K3 better than the KP? Thank you.

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01-12-2020, 06:37 AM	#2
aslyfox Seeker of Knowledge Join Date: Aug 2016 Location: Topeka, Kansas Photos: Gallery \| Albums Posts: 24,581	have you seen the KP in depth review yet - Quote: . . . AF Tracking Test Moving subject tracking during burst shooting is a good scenario for stress-testing a DSLR's focusing system. To find out just how much the KP's tracking autofocus has been improved compared to the K-3 (and older bodies), and how well it fares overall, we performed a moving AF test similar to the one in our original K-3 review. As shown in the illustration below, a bicyclist rode past the camera along a semicircular track, thus changing both his horizontal and vertical distance at any given time. KP vs K-3 autofocus test setup (camera hand-held) The camera was set to continuous-high mode with focus priority set. We used two AF point modes: center-point and SEL-M (25 points). Each test was repeated 3 times; the summed result is presented below. We used the DA 18-135mm lens (set to 135mm) rather than the faster 55-300mm PLM in order to better expose any differences between the two cameras. Our motivation for the AF mode selection was simple: center-point mode allows the camera to concentrate on focusing speed and accuracy alone, while the SEL-M mode shows us how well the camera can do both at the same time. Center Point Select-M Pentax KP 92% (46/50) 83% (43/52) Pentax K-3 62% (32/52) 59% (30/51) In-focus photo rate (sharp photos / total photos) The results show that while both cameras sustained roughly the same framerate, the KP outperformed the K-3 handsomely regarding AF. What's more impressive is that these cameras differ solely in software tweaks to the AF system. The test also shows that the single point mode can provide a higher keeper rate than multi-point mode assuming it is feasible for the photographer to keep the selected point on the subject at all times. Overall this shows that the KP is quite good for tracking, even without the fastest-focusing lens available. However, there is certainly room for improvement— the utility of the fancy multi-point mode is questionable as its focusing speed and accuracy falls noticeably short of center point mode. We previously performed this test with the Nikon D610 in 39-point tracking mode and captured 80 sharp photos, out of 82. While the KP can compete with this figure in single point mode, the competition's multi-point tracking is still comfortably ahead. . . . Read more at: Pentax KP Review - Focusing \| PentaxForums.com Reviews

01-12-2020, 06:43 AM	#3
TerryL Pentaxian Join Date: Jan 2018 Location: Virginia, USA Photos: Albums Posts: 850 Original Poster	Originally posted by aslyfox have you seen the KP in depth review yet - Read more at: Pentax KP Review - Focusing \| PentaxForums.com Reviews That definitely answers my question. Thank you.

01-12-2020, 07:44 AM	#4
Alnjpn Senior Member Join Date: May 2015 Location: Osaka Posts: 158	I can comment on the K3 but not the KP. I have had the k3 for 3 years and have had ongoing AF problems. It is fast but most certainly NOT accurate. (This is through the viewfinder, accuracy in Live View is fine). I have tried adjusting the lenses and cleaning the Af module but still the problem persists. This may be a one off problem although I have seen similar comments on this forum. I have an old Canon 6D which I use for portraits. While the AF is much slower it is considerably more accurate and reliable. If AF accuracy is important you might wan't to avoid the K3

01-12-2020, 07:53 AM	#5
aslyfox Seeker of Knowledge Join Date: Aug 2016 Location: Topeka, Kansas Photos: Gallery \| Albums Posts: 24,581	Originally posted by Alnjpn I can comment on the K3 but not the KP. I have had the k3 for 3 years and have had ongoing AF problems. It is fast but most certainly NOT accurate. (This is through the viewfinder, accuracy in Live View is fine). I have tried adjusting the lenses and cleaning the Af module but still the problem persists. This may be a one off problem although I have seen similar comments on this forum. I have an old Canon 6D which I use for portraits. While the AF is much slower it is considerably more accurate and reliable. If AF accuracy is important you might wan't to avoid the K3 have you checked the adjustable diopter ? some times that shifts on me and when I think I have a good focus I do not

01-12-2020, 07:54 AM	#6
Madaboutpix Site Supporter Join Date: Dec 2011 Location: North Rhine-Westphalia Posts: 1,440	K-3 user since 2014. Always running on the latest firmware. PDAF relatively fast and snappy, no inaccuracy problems with any of my Pentax DA lenses. The in-depth reviews will probably point out that the newer KP has improved AF, but that is only to be expected.

01-12-2020, 09:19 AM	#7
microlight Site Supporter Join Date: Sep 2011 Location: Hampshire, UK Posts: 2,129	The K-3, K-3II and KP all use the same SAFOX 11 27-point AF module. However, the processing algorithms used were improved for the K-3II from the original K-3, and then improved again for the KP.

01-12-2020, 10:31 AM	#8
TerryL Pentaxian Join Date: Jan 2018 Location: Virginia, USA Photos: Albums Posts: 850 Original Poster	The only reason I asked is I found a new K3 and am tempted to buy it. ---------- Post added 01-12-20 at 11:16 AM ---------- Originally posted by Alnjpn I can comment on the K3 but not the KP. I have had the k3 for 3 years and have had ongoing AF problems. It is fast but most certainly NOT accurate. (This is through the viewfinder, accuracy in Live View is fine). I have tried adjusting the lenses and cleaning the Af module but still the problem persists. This may be a one off problem although I have seen similar comments on this forum. I have an old Canon 6D which I use for portraits. While the AF is much slower it is considerably more accurate and reliable. If AF accuracy is important you might wan't to avoid the K3 I had similar problems with my K1 mkIi. Every lens I own was out of focus. My K1 was perfect. So, I sent it to Precision to check. Boy, did I dread that.