AF Speed vs Accuracy

Workingdog · 12-23-2007, 09:38 AM

I've read a lot of posts where one of the main complaints about the K10D is autofocus speed.
It's all relative though, isn't it? I mean certainly very fast and very accurate is the Holy Grail.
What about slower+more accurate vs. faster+less accurate, which is better? I suppose you need to answer questions like how much slower and how much less accurate? I suppose it also depends on your photographic subjects.
How does it all play out in the real world? I mean drag races are won and lost by milliseconds but the reality is that both cars are pretty darn fast and both would beat my corvette with only half their cylinders firing.
From what I've seen on this forum the C and N are "noticably" faster but the human brain is capable of differentiating between some very small time intervals. Is it of practical importance or is the K10D "fast enough"?
I know your replies will be interesting and informative.

**Canada_Rockies** · 12-23-2007, 09:48 AM

For my uses, the k10d is plenty fast enough. With my DA and DA* lenses, I can have fingers on the zoom ring and an index finger ready to touch up the focus on the focus ring as well. I really don't think it is in my best interests to let the camera decide where I should have the focus, anyway.

wlachan · 12-23-2007, 10:53 AM

I think the speed & accuracy scenario has been setup with the big assumption that both could not be achieved at the same time. There is no question that there are users found the Pentax AF performance lacking in some situations, low light and AF tracking for instance, and I agree. I dare say tracking race cars does not really challenge any AF ability to its limitation. As to myself, trying to follow fast action like weddings or parties at close range really put the Pentax AF performance to the test.

rvannatta · 12-23-2007, 11:51 AM

Originally posted by wlachan

I think the speed & accuracy scenario has been setup with the big assumption that both could not be achieved at the same time. There is no question that there are users found the Pentax AF performance lacking in some situations, low light and AF tracking for instance, and I agree. I dare say tracking race cars does not really challenge any AF ability to its limitation. As to myself, trying to follow fast action like weddings or parties at close range really put the Pentax AF performance to the test.

One must assume that the purpose of the introduction of the SDM is to address speed and noise complaints of the screw drive AF mechanisms. SDM has not yet percolated throughout
the Pentax family. As it appears that SDM will percolate further through the Pentax family
in the coming year, it would seem that comparing last years pentax technology to
the SDM type products of the the competition is a zero sum game. It gets us no where.

Now wishing that the SDM's would percolate faster--that's anoher story, but alas it seems
reasonable to expect that the long delayed long lenses with SDM will surface soon.

Rener · 12-23-2007, 12:30 PM

[QUOTE]

Originally posted by wlachan

I think the speed & accuracy scenario has been setup with the big assumption that both could not be achieved at the same time. There is no question that there are users found the Pentax AF performance lacking in some situations, low light and AF tracking for instance, and I agree. I dare say tracking race cars does not really challenge any AF ability to its limitation. As to myself, trying to follow fast action like weddings or parties at close range really put the Pentax AF performance to the test.

A fast action wedding? I thought the dragon dances are lot faster than any wedding that I have seen and yet they are well captured by PENTAX. There were a lot of action sports from the other forum that were posted and incredibly, most of the shots are good. Granted they were done in good light, but even my D80 shooting friend is having a hard time capturing subjects in a low light dancing hall. The keepers are low, that tells me that the issue with the PENTAX AF is getting blown out of proportion.

Cheers,

Rene

wlachan · 12-23-2007, 12:53 PM

[quote=OPTMEKX&;138722]

Quote:

A fast action wedding? I thought the dragon dances are lot faster than any wedding that I have seen and yet they are well captured by PENTAX. There were a lot of action sports from the other forum that were posted and incredibly, most of the shots are good. Granted they were done in good light, but even my D80 shooting friend is having a hard time capturing subjects in a low light dancing hall. The keepers are low, that tells me that the issue with the PENTAX AF is getting blown out of proportion.
Cheers,
Rene

There are many ways, or some say styles, of shooting weddings. Some can be done with Leica M, some need fast AF. I am not talking about the dances (and there are many more weddings than just western style btw), but rather, trying to capture the moments up close as it goes. But really, these days one cannot discuss the limitation of Pentax equipments without getting being accused, can we?

thibs · 12-23-2007, 01:58 PM

IMO the AF performace issue is somewhat blown out of proportion but still, I'm the first toadmit that under bad lighting and e.g. inside my house with kids moving (not that much, it's not the garden, just in house) the K10D has a very hard time keeping up especially in C-AF mode with my 16-45.

I thought my 18-55 would be quite worse beacuse of /5.6 at the long end but no. So there's indde quite a lot of improments possible.

However, stating that Pentax AF plain sucks is stupid. It may suck for certain applications but when it works it does work well, and IS precise.

nosnoop · 12-23-2007, 04:32 PM

Originally posted by thibs

IMO the AF performace issue is somewhat blown out of proportion...

Exactly, don't take my word, here's what a respected reviewer, Klaus Schroiff, says about K10D's AF, and he has a lot of experience handling all the DSLRs:

Pentax K10D Review / Test Report

Quote:

AF Performance
Fast - really fast! AF speed and the accuracy of the K10D are impressive even with the cheap kit lenses and also in dark conditions. The brilliant AF speed also shows up in continuous AF mode.

RiceHigh · 12-24-2007, 08:08 PM

Originally posted by Workingdog

What about slower+more accurate vs. faster+less accurate, which is better?

How about "faster and more accurate" and "slower and less accurate"??

Quote:

Is it of practical importance or is the K10D "fast enough"?
I know your replies will be interesting and informative.

That depends on what you shoot and your applications.

equinox · 12-25-2007, 08:19 AM

Originally posted by nosnoop

Exactly, don't take my word, here's what a respected reviewer, Klaus Schroiff, says about K10D's AF, and he has a lot of experience handling all the DSLRs:

Pentax K10D Review / Test Report

nosnoop, thanks for the link. An excellent read.

12-23-2007, 09:38 AM	#1
Workingdog Veteran Member Join Date: Dec 2007 Location: York, PA Photos: Gallery Posts: 736	AF Speed vs Accuracy I've read a lot of posts where one of the main complaints about the K10D is autofocus speed. It's all relative though, isn't it? I mean certainly very fast and very accurate is the Holy Grail. What about slower+more accurate vs. faster+less accurate, which is better? I suppose you need to answer questions like how much slower and how much less accurate? I suppose it also depends on your photographic subjects. How does it all play out in the real world? I mean drag races are won and lost by milliseconds but the reality is that both cars are pretty darn fast and both would beat my corvette with only half their cylinders firing. From what I've seen on this forum the C and N are "noticably" faster but the human brain is capable of differentiating between some very small time intervals. Is it of practical importance or is the K10D "fast enough"? I know your replies will be interesting and informative.

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12-23-2007, 09:48 AM	#2
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	For my uses, the k10d is plenty fast enough. With my DA and DA* lenses, I can have fingers on the zoom ring and an index finger ready to touch up the focus on the focus ring as well. I really don't think it is in my best interests to let the camera decide where I should have the focus, anyway.

12-23-2007, 10:53 AM	#3
wlachan Veteran Member Join Date: Sep 2006 Location: Canada Photos: Albums Posts: 2,625	I think the speed & accuracy scenario has been setup with the big assumption that both could not be achieved at the same time. There is no question that there are users found the Pentax AF performance lacking in some situations, low light and AF tracking for instance, and I agree. I dare say tracking race cars does not really challenge any AF ability to its limitation. As to myself, trying to follow fast action like weddings or parties at close range really put the Pentax AF performance to the test.

12-23-2007, 11:51 AM	#4
rvannatta Pentaxian Join Date: Aug 2007 Location: Apiary, Oregon Photos: Gallery Posts: 1,181	Originally posted by wlachan I think the speed & accuracy scenario has been setup with the big assumption that both could not be achieved at the same time. There is no question that there are users found the Pentax AF performance lacking in some situations, low light and AF tracking for instance, and I agree. I dare say tracking race cars does not really challenge any AF ability to its limitation. As to myself, trying to follow fast action like weddings or parties at close range really put the Pentax AF performance to the test. One must assume that the purpose of the introduction of the SDM is to address speed and noise complaints of the screw drive AF mechanisms. SDM has not yet percolated throughout the Pentax family. As it appears that SDM will percolate further through the Pentax family in the coming year, it would seem that comparing last years pentax technology to the SDM type products of the the competition is a zero sum game. It gets us no where. Now wishing that the SDM's would percolate faster--that's anoher story, but alas it seems reasonable to expect that the long delayed long lenses with SDM will surface soon.

12-23-2007, 12:30 PM	#5
Rener Inactive Account Join Date: Feb 2007 Location: Canada Posts: 292	[QUOTE] Originally posted by wlachan I think the speed & accuracy scenario has been setup with the big assumption that both could not be achieved at the same time. There is no question that there are users found the Pentax AF performance lacking in some situations, low light and AF tracking for instance, and I agree. I dare say tracking race cars does not really challenge any AF ability to its limitation. As to myself, trying to follow fast action like weddings or parties at close range really put the Pentax AF performance to the test. A fast action wedding? I thought the dragon dances are lot faster than any wedding that I have seen and yet they are well captured by PENTAX. There were a lot of action sports from the other forum that were posted and incredibly, most of the shots are good. Granted they were done in good light, but even my D80 shooting friend is having a hard time capturing subjects in a low light dancing hall. The keepers are low, that tells me that the issue with the PENTAX AF is getting blown out of proportion. Cheers, Rene

12-23-2007, 12:53 PM	#6
wlachan Veteran Member Join Date: Sep 2006 Location: Canada Photos: Albums Posts: 2,625	[quote=OPTMEKX&;138722] Quote: A fast action wedding? I thought the dragon dances are lot faster than any wedding that I have seen and yet they are well captured by PENTAX. There were a lot of action sports from the other forum that were posted and incredibly, most of the shots are good. Granted they were done in good light, but even my D80 shooting friend is having a hard time capturing subjects in a low light dancing hall. The keepers are low, that tells me that the issue with the PENTAX AF is getting blown out of proportion. Cheers, Rene There are many ways, or some say styles, of shooting weddings. Some can be done with Leica M, some need fast AF. I am not talking about the dances (and there are many more weddings than just western style btw), but rather, trying to capture the moments up close as it goes. But really, these days one cannot discuss the limitation of Pentax equipments without getting being accused, can we?

12-23-2007, 01:58 PM	#7
thibs Pentaxian Join Date: Jun 2007 Location: Belgium Photos: Albums Posts: 7,001	IMO the AF performace issue is somewhat blown out of proportion but still, I'm the first toadmit that under bad lighting and e.g. inside my house with kids moving (not that much, it's not the garden, just in house) the K10D has a very hard time keeping up especially in C-AF mode with my 16-45. I thought my 18-55 would be quite worse beacuse of /5.6 at the long end but no. So there's indde quite a lot of improments possible. However, stating that Pentax AF plain sucks is stupid. It may suck for certain applications but when it works it does work well, and IS precise.

12-23-2007, 04:32 PM	#8
nosnoop Veteran Member Join Date: Feb 2007 Posts: 1,299	Originally posted by thibs IMO the AF performace issue is somewhat blown out of proportion... Exactly, don't take my word, here's what a respected reviewer, Klaus Schroiff, says about K10D's AF, and he has a lot of experience handling all the DSLRs: Pentax K10D Review / Test Report Quote: AF Performance Fast - really fast! AF speed and the accuracy of the K10D are impressive even with the cheap kit lenses and also in dark conditions. The brilliant AF speed also shows up in continuous AF mode.

12-24-2007, 08:08 PM	#9
RiceHigh Veteran Member Join Date: Nov 2006 Location: Hong Kong Posts: 1,934	Originally posted by Workingdog What about slower+more accurate vs. faster+less accurate, which is better? How about "faster and more accurate" and "slower and less accurate"?? Quote: Is it of practical importance or is the K10D "fast enough"? I know your replies will be interesting and informative. That depends on what you shoot and your applications.

12-25-2007, 08:19 AM	#10
equinox Senior Member Join Date: Sep 2006 Location: Canada Posts: 159	Originally posted by nosnoop Exactly, don't take my word, here's what a respected reviewer, Klaus Schroiff, says about K10D's AF, and he has a lot of experience handling all the DSLRs: Pentax K10D Review / Test Report nosnoop, thanks for the link. An excellent read.