What is better about Auto Focus on other brands compared to Pentax?

TropicalMonkey · 03-10-2016, 01:00 PM

Many users report Auto Focusing to be better on other brands compared to Pentax. Does that mean the focus point is more accurate or just that focusing is quicker?

Can SDM lenses on a Pentax K3 perform as fast as SDM on other brands for wide apertures? The PF's own moving target test with K3 did not mention what aperture they used to get 97% keeper rate with D610 vs 67% with K3.

Last edited by TropicalMonkey; 03-10-2016 at 01:06 PM.

Adam · 03-10-2016, 01:05 PM

Originally posted by TropicalMonkey

Many users report that Auto Focusing is better on other brands compared to Pentax. Does that mean the focus point is more accurate or just that focusing is quicker?

Can SDM lenses on a Pentax K3 perform as fast as SDM on other brands for wide apertures? The PF's own moving target test with K3 did not mention what aperture they used to get 97% keeper rate with D610 vs 67% with K3.

The main advantage of other systems is in terms of tracking reliability / speed, and lens motor speed. In terms of accuracy Pentax is near the top, with AF sensitivity to -3 EV.

TropicalMonkey · 03-10-2016, 01:08 PM

Thanks Adam!
BTW, do you know what aperture was used for the competition between K3 and D650 (in K3 review), was that wide open?

pathdoc · 03-10-2016, 01:14 PM - **1 Like**

Originally posted by Adam

The main advantage of other systems is in terms of tracking reliability / speed, and lens motor speed. In terms of accuracy Pentax is near the top, with AF sensitivity to -3 EV.

Let me know if I've got this right. I think this translates to "Other systems will keep lock on a moving target better. Pentax will nail a stationary target better, and do it in lower light."

**maxfield_photo** · 03-10-2016, 01:32 PM

There are also consideration like number of AF points, their distribution across the frame, and the size (fineness/coarseness) of individual AF points. The high-end sports cameras from Canon and Nikon tend to be better speced in these areas, but it comes at the cost of size and $$$. Nikon is probably regarded as the king with their 3D color tracking, and this tech has trickled down even into some of their beginner models. Canon has done some impressive things too like phase detect sensors on the imaging sensor for quicker live view focusing, and PDAF face recognition on select cameras. The lenses tend to have faster focus motors from what I understand.

For portrait shooting which is mainly what I do, the Pentax AF system is more than adequate, and I'd go as far as to say the low-light focusing capabilities are quite impressive. I think if your primary interest is in portraiture, landscapes, product shots, architecture, street shooting, family shots, events, weddings, macro, even ground-based wildlife, you shouldn't let the AF capabilities turn you off to Pentax. Birds in flight might be a little harder, but there's always the amazing catch-in-focus ability to help with that. It's really only sports shooters that need to let it factor into their decision, and really, a much larger consideration for those folks should be the availability of large aperture super-telephoto lenses that other brands offer.

normhead · 03-10-2016, 01:35 PM - **1 Like**

There have been studio that said Pentax was better for anything but tracking as well, but this stuff really depends on what camera mode and lens combinations you're talking about. If i have one complaint with the folks that answer these questions it's they give general answers, in which they define no parameters.

I would have said, if you pay more money for a Canon or Nikon system you can get better AF. The issue with Pentax is not that Pentax product is any worse than comparable CaNikon product, it's that they don't have as many pricier more specialized options as bigger companies. You can't pay more for a special interest type product even if you want to. That is completely irrelevant if you don't want to.

That just encourages the guys who come one here and show us the great pictures they get of their dog with their D750. I won't pay $2500 to get a few "better" pictures of my dog, so that's pretty much irrelevant to me. It would be cheaper to just higher some guy with a D750 to take those pictures if i wanted them. How many pictures of your dog running at you do you even want?

The conversations just get stupid.

Adam · 03-10-2016, 01:38 PM

Originally posted by pathdoc

Let me know if I've got this right. I think this translates to "Other systems will keep lock on a moving target better. Pentax will nail a stationary target better, and do it in lower light."

For the most part. I think other systems are still a bit better at predicting your subject in multi-point AF mode (based on comparing the K-1 to the D810). Maybe it's just a question of AF point count.

Adam
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David&karen · 03-10-2016, 02:41 PM

The one nagging issue for us is facial and eye tracking using OVF that Nikon D750 and up do so well. During a fast paced wedding, it can really help to nail the pictures you really want/need and speeds the whole process up. The Canon version used in their high end cameras really does not work(experience) but we hear the sony is really nice. With grey market D750's going for $1399 this is a real issue for us if we start weddings again. We really do not understand why the Pentax K3 does not do this as the hardware seems to be there, and so far the K1 has not been shown to do this, but it is still early to dismiss the K1. Time will tell...

rawr · 03-10-2016, 02:53 PM

Good AF performance is not a brand issue, its a camera model issue.

Point being, both Nikon and Canon (and Sony) have cameras with class leading AF, but also many cameras with totally unexceptional AF. It's not Canon vs Nikon vs Pentax vs Sony vs Olympus vs Panasonic generically, it needs to be a model by model assessment.

As other's have noted, assessing 'better' autofocus also depends on your usage scenarios (eg landscape vs sport vs macro vs video) and lens requirements (super-telephoto or ultra-wide or macro). If you follow this path further, sometimes these requirements may even mandate very specific AF capabilities (eg extreme low light sensitivity) or features (eg face tracking or AF tracking in video) that may effectively narrow down your choices to very specific cameras even across brands.

**ffking** · 03-10-2016, 03:03 PM

To me, the biggest weakness in the Pentax AF system is its inability to recognise that it's going in the wrong direction - if it can't find focus, it will go all the way to near focus before heading out on its way to infinity, even if focus is closer to infinity than the starting position. I don't have a lot of experience of other systems, but I've not noticed this extreme hunting in them.

TropicalMonkey · 03-10-2016, 03:11 PM

In modern SDM lenses, focus motor is within, and it is pretty smooth while focusing too. So Pentax focusing speed should be comparable to other brands while using SDM lenses. Am I correct in that assumption?

rawr · 03-10-2016, 03:22 PM

Originally posted by TropicalMonkey

So Pentax focusing speed should be comparable to other brands while using SDM lenses. Am I correct in that assumption?

Depends on choosing an equivalent lens across brands (eg 300 f4 or 70-200 f2.8), but generally I would say yes (or close enough).

Also depends on the version of Pentax 'SDM' you are comparing with other brands (original SDM like in 16-50, or latest SDM like in the newer DFA's, or Sigma HSM running on Pentax K). In particular, Sigma HSM on Pentax would perform much the same as Sigma HSM on Nikon, one would think, if similar cameras with similar settings hosted the same lens.

traderdrew · 03-10-2016, 04:13 PM

Originally posted by pathdoc

Let me know if I've got this right. I think this translates to "Other systems will keep lock on a moving target better. Pentax will nail a stationary target better, and do it in lower light."

Other systems (Nikon and Canon) photograph birds in flight better and I have seen this in the field especially that D4 but it is a $6,000 camera. I personally wait for the bird to fly into an optimal range and then take the shot. Successive shots seem to slow the auto focus down.

I did read about an infrared auto focus patent around here. A hybrid focus system with that should solve that problem I would think. Gives me some hope.

Winder · 03-11-2016, 08:55 PM

Originally posted by TropicalMonkey

In modern SDM lenses, focus motor is within, and it is pretty smooth while focusing too. So Pentax focusing speed should be comparable to other brands while using SDM lenses. Am I correct in that assumption?

It more than just the motor. There seems to be more latency with Pentax SDM glass.

**clackers** · 03-12-2016, 01:49 AM

FWIW, @Gary reports in another thread:

"Excellent news from Sandy Ramirez about the K-1's autofocus.

"the K-1 is an incredible camera. It's on par with the top of the line Canons or Nikons. Seriously I now will get myself one, a great companion to my 645Z."
(link)

Autofocus "on par and slightly more accurate than the Canon 1DX."
(link)

03-10-2016, 01:00 PM	#1
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304	What is better about Auto Focus on other brands compared to Pentax? Many users report Auto Focusing to be better on other brands compared to Pentax. Does that mean the focus point is more accurate or just that focusing is quicker? Can SDM lenses on a Pentax K3 perform as fast as SDM on other brands for wide apertures? The PF's own moving target test with K3 did not mention what aperture they used to get 97% keeper rate with D610 vs 67% with K3. Last edited by TropicalMonkey; 03-10-2016 at 01:06 PM.

03-10-2016, 01:05 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by TropicalMonkey Many users report that Auto Focusing is better on other brands compared to Pentax. Does that mean the focus point is more accurate or just that focusing is quicker? Can SDM lenses on a Pentax K3 perform as fast as SDM on other brands for wide apertures? The PF's own moving target test with K3 did not mention what aperture they used to get 97% keeper rate with D610 vs 67% with K3. The main advantage of other systems is in terms of tracking reliability / speed, and lens motor speed. In terms of accuracy Pentax is near the top, with AF sensitivity to -3 EV. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-10-2016, 04:13 PM	#13
traderdrew Veteran Member Join Date: Jun 2010 Location: Florida Photos: Gallery \| Albums Posts: 640	Originally posted by pathdoc Let me know if I've got this right. I think this translates to "Other systems will keep lock on a moving target better. Pentax will nail a stationary target better, and do it in lower light." Other systems (Nikon and Canon) photograph birds in flight better and I have seen this in the field especially that D4 but it is a $6,000 camera. I personally wait for the bird to fly into an optimal range and then take the shot. Successive shots seem to slow the auto focus down. I did read about an infrared auto focus patent around here. A hybrid focus system with that should solve that problem I would think. Gives me some hope. Last edited by traderdrew; 03-10-2016 at 04:19 PM.

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03-10-2016, 01:08 PM	#3
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304 Original Poster	Thanks Adam! BTW, do you know what aperture was used for the competition between K3 and D650 (in K3 review), was that wide open?

03-10-2016, 01:14 PM - 1 Like	#4
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	Originally posted by Adam The main advantage of other systems is in terms of tracking reliability / speed, and lens motor speed. In terms of accuracy Pentax is near the top, with AF sensitivity to -3 EV. Let me know if I've got this right. I think this translates to "Other systems will keep lock on a moving target better. Pentax will nail a stationary target better, and do it in lower light."

03-10-2016, 01:32 PM	#5
maxfield_photo Site Supporter Join Date: Mar 2011 Location: Cincinnati, OH Posts: 1,216	There are also consideration like number of AF points, their distribution across the frame, and the size (fineness/coarseness) of individual AF points. The high-end sports cameras from Canon and Nikon tend to be better speced in these areas, but it comes at the cost of size and $$$. Nikon is probably regarded as the king with their 3D color tracking, and this tech has trickled down even into some of their beginner models. Canon has done some impressive things too like phase detect sensors on the imaging sensor for quicker live view focusing, and PDAF face recognition on select cameras. The lenses tend to have faster focus motors from what I understand. For portrait shooting which is mainly what I do, the Pentax AF system is more than adequate, and I'd go as far as to say the low-light focusing capabilities are quite impressive. I think if your primary interest is in portraiture, landscapes, product shots, architecture, street shooting, family shots, events, weddings, macro, even ground-based wildlife, you shouldn't let the AF capabilities turn you off to Pentax. Birds in flight might be a little harder, but there's always the amazing catch-in-focus ability to help with that. It's really only sports shooters that need to let it factor into their decision, and really, a much larger consideration for those folks should be the availability of large aperture super-telephoto lenses that other brands offer.

03-10-2016, 01:35 PM - 1 Like	#6
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	There have been studio that said Pentax was better for anything but tracking as well, but this stuff really depends on what camera mode and lens combinations you're talking about. If i have one complaint with the folks that answer these questions it's they give general answers, in which they define no parameters. I would have said, if you pay more money for a Canon or Nikon system you can get better AF. The issue with Pentax is not that Pentax product is any worse than comparable CaNikon product, it's that they don't have as many pricier more specialized options as bigger companies. You can't pay more for a special interest type product even if you want to. That is completely irrelevant if you don't want to. That just encourages the guys who come one here and show us the great pictures they get of their dog with their D750. I won't pay $2500 to get a few "better" pictures of my dog, so that's pretty much irrelevant to me. It would be cheaper to just higher some guy with a D750 to take those pictures if i wanted them. How many pictures of your dog running at you do you even want? The conversations just get stupid.

03-10-2016, 01:38 PM	#7
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by pathdoc Let me know if I've got this right. I think this translates to "Other systems will keep lock on a moving target better. Pentax will nail a stationary target better, and do it in lower light." For the most part. I think other systems are still a bit better at predicting your subject in multi-point AF mode (based on comparing the K-1 to the D810). Maybe it's just a question of AF point count. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-10-2016, 02:41 PM	#8
David&karen Veteran Member Join Date: Jan 2011 Posts: 327	The one nagging issue for us is facial and eye tracking using OVF that Nikon D750 and up do so well. During a fast paced wedding, it can really help to nail the pictures you really want/need and speeds the whole process up. The Canon version used in their high end cameras really does not work(experience) but we hear the sony is really nice. With grey market D750's going for $1399 this is a real issue for us if we start weddings again. We really do not understand why the Pentax K3 does not do this as the hardware seems to be there, and so far the K1 has not been shown to do this, but it is still early to dismiss the K1. Time will tell...

03-10-2016, 02:53 PM	#9
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Good AF performance is not a brand issue, its a camera model issue. Point being, both Nikon and Canon (and Sony) have cameras with class leading AF, but also many cameras with totally unexceptional AF. It's not Canon vs Nikon vs Pentax vs Sony vs Olympus vs Panasonic generically, it needs to be a model by model assessment. As other's have noted, assessing 'better' autofocus also depends on your usage scenarios (eg landscape vs sport vs macro vs video) and lens requirements (super-telephoto or ultra-wide or macro). If you follow this path further, sometimes these requirements may even mandate very specific AF capabilities (eg extreme low light sensitivity) or features (eg face tracking or AF tracking in video) that may effectively narrow down your choices to very specific cameras even across brands.

03-10-2016, 03:03 PM	#10
ffking Site Supporter Join Date: Nov 2015 Location: Old South Wales Posts: 6,038	To me, the biggest weakness in the Pentax AF system is its inability to recognise that it's going in the wrong direction - if it can't find focus, it will go all the way to near focus before heading out on its way to infinity, even if focus is closer to infinity than the starting position. I don't have a lot of experience of other systems, but I've not noticed this extreme hunting in them.

03-10-2016, 03:11 PM	#11
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304 Original Poster	In modern SDM lenses, focus motor is within, and it is pretty smooth while focusing too. So Pentax focusing speed should be comparable to other brands while using SDM lenses. Am I correct in that assumption?

03-10-2016, 03:22 PM	#12
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Originally posted by TropicalMonkey So Pentax focusing speed should be comparable to other brands while using SDM lenses. Am I correct in that assumption? Depends on choosing an equivalent lens across brands (eg 300 f4 or 70-200 f2.8), but generally I would say yes (or close enough). Also depends on the version of Pentax 'SDM' you are comparing with other brands (original SDM like in 16-50, or latest SDM like in the newer DFA's, or Sigma HSM running on Pentax K). In particular, Sigma HSM on Pentax would perform much the same as Sigma HSM on Nikon, one would think, if similar cameras with similar settings hosted the same lens.

03-11-2016, 08:55 PM	#14
Winder Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 6,617	Originally posted by TropicalMonkey In modern SDM lenses, focus motor is within, and it is pretty smooth while focusing too. So Pentax focusing speed should be comparable to other brands while using SDM lenses. Am I correct in that assumption? It more than just the motor. There seems to be more latency with Pentax SDM glass.

03-12-2016, 01:49 AM	#15
clackers Otis Memorial Pentaxian Join Date: Jul 2013 Location: Melbourne Photos: Albums Posts: 16,397	FWIW, @Gary reports in another thread: "Excellent news from Sandy Ramirez about the K-1's autofocus. "the K-1 is an incredible camera. It's on par with the top of the line Canons or Nikons. Seriously I now will get myself one, a great companion to my 645Z." (link) Autofocus "on par and slightly more accurate than the Canon 1DX." (link)