K-7 and AF performance

Ray Pulley · 05-21-2009, 03:21 PM

Quote:

As far as trying to take it personal, believe it or not, I have some experience of guys talking down to me like I couldn't possibly understand anything technical, who might look at my choice or kludge of gear and say, "silly girl, you can't do that with that."

My customary response is: Watch me.

This was not about you and your feminine strengths or weaknesses.

Get over yourself.

BTW, how do you know I am a guy?

Sort of presumptuous of you...

Ray

robgo2 · 05-21-2009, 03:24 PM

Originally posted by Ratmagiclady

Eh, Golden. It'll do.

What's that make the complainers, sitting around waiting on a difference of .04 seconds? I must be getting old.

I think maybe why I'm tending to get a little peeved here is that it seems the message from all the, if you don't mind my saying, geekery, is, 'You can't unless you buy this, you can't unless you buy that.'

That's no way to teach or learn photography.

(So, sorry if it does cheese me off a little. I like talking about cameras, too. But I think there's a lot of loss of perspective about what really gets the job done involved. )

I am a K10D user, and my focusing needs are relatively simple, but I do occasionally find myself waiting for the camera to end its hunt. That said, I wonder about those who insist that if the new K-7 does not achieve the same focusing speed as Camera X, it will have to be regarded as a major disappointment. Whatever happened to "good enough to serve my purposes?" For most users, the K10D and K20D are already adequate in that sense. I understand that other users truly require better focus tracking, and I certainly hope that the K-7 will provide it. But to set arbitrary standards that must be met "or else," is silly.

Rob

Class A · 05-21-2009, 03:40 PM

Originally posted by blende8

How do you think this is realized?

A phase detection system uses prisms (it works not unlike a split prism focusing screen). This causes a dependency on the wavelength. That is why Pentax AF front focuses under Tungsten light.

The new sensor is responsible for detecting the light temperature and it's input is used to compensate the measurement of the phase detection system.

At least that is my understanding.

Originally posted by Ray Pulley

I would be hard-pressed to believe that adding a sensor that has to be read and processed and then taking that data and using it to adjust the AF would make the whole process FASTER.

Such calculations don't take any noticeably time.

Originally posted by Ray Pulley

More accurate in certain lighting, yes, as that is what it is designed to do, but Faster, no.

How do you know? You may be right, but perhaps the additional information can be used to disambiguate information from the phase detection system and thus help to speed up AF? I'm not saying this is the case or even likely to be the case, but when I don't know I try to not talk in absolutes.

Originally posted by Wheatfield

If you go out and use two different cameras, and one just seems to have snappier performance...

Then one seems to have a snappier performance. Only a scientific evaluation will tell you whether you are imagining things (we humans are great in seeing things which are not there) or whether there are actually facts.

Originally posted by Wheatfield

I have more interest in this sort of anecdotal approach than a purely quantifed approach that may or may not have anything to do with actual photography.

Fair enough. To become happy one should do what makes one happy. If you are happy by basing your decision on impressions that may be influenced by a lot of factors and then are happy with the result of such a decision then that would be the right thing to do for you.

To some people it is obvious that homoeopathy helps (beyond a placebo effect).

Scientific approach, it is not. -- Yoda.

Class A · 05-21-2009, 03:58 PM

Originally posted by GoldenWreckedAngle

Shutter lag at full auto focus:

Canon 50D = 0.131 (W) seconds
Pentax K20D = 0.174 (W) seconds
Nikon D700 = 0.197 (W) seconds
Canon 5D Mrk II = 0.206 (W) seconds
Nikon D90 = 0.208 (W) seconds
Nikon D300 = 0.227 (W) seconds
Pentax K10D = 0.254 (W) seconds

Ah, now I understand why everyone calls the K20D AF sluggish, sub-par, etc.................... NOT!

When I was shopping for a DSLR (in late 2008) I read about Pentax AF being slow and was concerned about its applicability. When I first used it, I couldn't understand what people were on about. Maybe slower than competitors but no way slow in practical terms (fast action shooting aside). The above numbers tell me that even in relative terms, AF speed is more than sufficient at least when looked at from the relevant shutter lag perspective.

Granted there might be some applications (very low light, fast moving action) where the Pentax AF still has room for improvement but I don't get the apparently common agreement about Pentax AF lacking in general.

asdf · 05-21-2009, 04:03 PM

Originally posted by Class A

To some people it is obvious that homoeopathy helps (beyond a placebo effect).

A homeopathic camera has a diluted 0MP sensor.

nosnoop · 05-21-2009, 04:25 PM

Originally posted by Wheatfield

If you go out and use two different cameras, and one just seems to have snappier performance, then you've a qualified comparison that one camera is faster than the other.

Not really. You would be surprised how much noise could influence your perception. For example, using one with USM lens may give you an impression it is a faster and more accurate simply because you cannot hear that the AF is working even if it takes just as long.

Ratmagiclady · 05-21-2009, 04:41 PM

Originally posted by Ray Pulley

No it is already a waste of time.

Ray

Ok, yeah. Can't have anybody wasting any *time...*

Here... on the Internet.

Ratmagiclady · 05-21-2009, 04:50 PM

Originally posted by Ray Pulley

This was not about you and your feminine strengths or weaknesses.

Get over yourself.

BTW, how do you know I am a guy?

Sort of presumptuous of you...

Ray

Actually, I didn't say you were, just that I'd had that experience. If you resemble it... draw your own conclusions, if it's not already clear.

Ratmagiclady · 05-21-2009, 05:05 PM

Originally posted by Clem Nichols

Just to interject a comment here between the back-and-forth comments of Ray and the Ratmagiclady, an earlier poster in this thread mentioned that he had not seen anything mentioned about the speed of the K7's AF-C. Mark Dimalanta in his review reports that AF tracking in AF-C is "vastly improved". His review can be seen here:

chasing light...: Initial Impressions of the Pentax K7

CN

Anyway, yeah, I'm definitely more inclined to believe the guy who came up with the nicely-sharp surfer photos than people trying to theoretically-bash what they haven't used in the field, though one might well presume he has reason to have good feelings toward Pentax.

Not sure what the deal about 'It's placebo effect' is supposed to be, though, what's gonna happen, someone come along and un-focus my photographs?

pingflood · 05-21-2009, 07:49 PM

Originally posted by GoldenWreckedAngle

The shutter lag at full auto focus is actually probably a more accurate number for real world shooting. This is kind of interesting:

Shutter lag at full auto focus:

Canon 50D = 0.131 (W) seconds
Pentax K20D = 0.174 (W) seconds
Nikon D700 = 0.197 (W) seconds
Canon 5D Mrk II = 0.206 (W) seconds
Nikon D90 = 0.208 (W) seconds
Nikon D300 = 0.227 (W) seconds
Pentax K10D = 0.254 (W) seconds

Now go grab a D300 and a K20D and go do some actual shooting and see which one performs better.

Honestly, I find it hard to believe that people claiming the K20D is as fast as or faster than the current prosumer cameras from the competition have ever shot with them. You can keep picking tests or setups that'll show an advantage, but in the end photography is done in the real world and that's where the true performance shows. The K20D is a very good, no a GREAT camera, but it doesn't smoke the competition in every area. You can keep trying to prove it does, or keep deluding yourself into believing so, but from somebody who's shot and handled a multitude of bodies going from ancient Leicas to viewcameras to current pro gear, IT AIN'T SO. Believe me, I didn't want to spend thousands more to get what I really wanted in a camera, but the difference was significant enough that I couldn't ignore it.

pingflood · 05-21-2009, 07:54 PM

Originally posted by Ratmagiclady

Eh, Golden. It'll do.

What's that make the complainers, sitting around waiting on a difference of .04 seconds? I must be getting old.

I think maybe why I'm tending to get a little peeved here is that it seems the message from all the, if you don't mind my saying, geekery, is, 'You can't unless you buy this, you can't unless you buy that.'

That's no way to teach or learn photography.

(So, sorry if it does cheese me off a little. I like talking about cameras, too. But I think there's a lot of loss of perspective about what really gets the job done involved. )

I think the whole "You can't" thing is a strawman conjured up by more than a few people. Honestly, how many people here are saying you _can't_ shoot birds in flight, car races, motocross, whatever with a Pentax DSLR or even a manual focus film body? What I see stated over and over again is that some other cameras make it EASIER to get the shots you want by doing what you ask them to well and rapidly. The world isn't black or white -- people actually ARE reasonable and present reasonable opinions and thoughts if you pay attention to what they're saying instead of lumping them into "pro" or "anti" categories.

edit: and before somebody mocks "easy" as not-true-photography, go carry a freakin' 4x5 around everywhere or better yet go coat some plates and don't relly on the crutches of manufactured film/sensors. Or better yet, hole yourself up in a camera obscura and trace out your action shots on a wall, because you wouldn't want to rely on equipment to do the work for you. Then you can sit around and deride all the other pretend-photographers, the snapshooters, and complain about their obsession with gear and lack of real skills.

edit2: not aimed towards you, Ratmagiclady, just an overall observation of common themes here lately...

dafiryde · 05-21-2009, 07:57 PM

by chance do you think the original poster would reply , since he claimed to have an on hands experience with the K7 or was he BS

Dave

Ray Pulley · 05-21-2009, 08:00 PM

Quote:

Such calculations don't take any noticeably time.

Quote:

I'm not saying this is the case or even likely to be the case, but when I don't know I try to not talk in absolutes.

Really?

See above.....

Ray

Class A · 05-21-2009, 10:36 PM

Originally posted by Ray Pulley

Really?

See above.....

I disagree with you. Let's leave it at that.

blende8 · 05-22-2009, 01:07 AM

Originally posted by Class A

A phase detection system uses prisms (it works not unlike a split prism focusing screen). This causes a dependency on the wavelength. That is why Pentax AF front focuses under Tungsten light.

The new sensor is responsible for detecting the light temperature and it's input is used to compensate the measurement of the phase detection system.

At least that is my understanding.

I agree that it sounds like that.
I am wondering where this sensor is situated. Within the AF unit?

05-21-2009, 03:21 PM	#61
Ray Pulley Veteran Member Join Date: Jan 2007 Location: Fallon Nevada Photos: Albums Posts: 504	Yawnnnnn Quote: As far as trying to take it personal, believe it or not, I have some experience of guys talking down to me like I couldn't possibly understand anything technical, who might look at my choice or kludge of gear and say, "silly girl, you can't do that with that." My customary response is: Watch me. This was not about you and your feminine strengths or weaknesses. Get over yourself. BTW, how do you know I am a guy? Sort of presumptuous of you... Ray

05-21-2009, 08:00 PM	#73
Ray Pulley Veteran Member Join Date: Jan 2007 Location: Fallon Nevada Photos: Albums Posts: 504	Hoisted and Petard comes to mind.... Quote: Such calculations don't take any noticeably time. Quote: I'm not saying this is the case or even likely to be the case, but when I don't know I try to not talk in absolutes. Really? See above..... Ray

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05-21-2009, 03:24 PM	#62
robgo2 Veteran Member Join Date: Jan 2007 Location: New Mexico Photos: Albums Posts: 1,125	Originally posted by Ratmagiclady Eh, Golden. It'll do. What's that make the complainers, sitting around waiting on a difference of .04 seconds? I must be getting old. I think maybe why I'm tending to get a little peeved here is that it seems the message from all the, if you don't mind my saying, geekery, is, 'You can't unless you buy this, you can't unless you buy that.' That's no way to teach or learn photography. (So, sorry if it does cheese me off a little. I like talking about cameras, too. But I think there's a lot of loss of perspective about what really gets the job done involved. ) I am a K10D user, and my focusing needs are relatively simple, but I do occasionally find myself waiting for the camera to end its hunt. That said, I wonder about those who insist that if the new K-7 does not achieve the same focusing speed as Camera X, it will have to be regarded as a major disappointment. Whatever happened to "good enough to serve my purposes?" For most users, the K10D and K20D are already adequate in that sense. I understand that other users truly require better focus tracking, and I certainly hope that the K-7 will provide it. But to set arbitrary standards that must be met "or else," is silly. Rob

05-21-2009, 03:40 PM	#63
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by blende8 How do you think this is realized? A phase detection system uses prisms (it works not unlike a split prism focusing screen). This causes a dependency on the wavelength. That is why Pentax AF front focuses under Tungsten light. The new sensor is responsible for detecting the light temperature and it's input is used to compensate the measurement of the phase detection system. At least that is my understanding. Originally posted by Ray Pulley I would be hard-pressed to believe that adding a sensor that has to be read and processed and then taking that data and using it to adjust the AF would make the whole process FASTER. Such calculations don't take any noticeably time. Originally posted by Ray Pulley More accurate in certain lighting, yes, as that is what it is designed to do, but Faster, no. How do you know? You may be right, but perhaps the additional information can be used to disambiguate information from the phase detection system and thus help to speed up AF? I'm not saying this is the case or even likely to be the case, but when I don't know I try to not talk in absolutes. Originally posted by Wheatfield If you go out and use two different cameras, and one just seems to have snappier performance... Then one seems to have a snappier performance. Only a scientific evaluation will tell you whether you are imagining things (we humans are great in seeing things which are not there) or whether there are actually facts. Originally posted by Wheatfield I have more interest in this sort of anecdotal approach than a purely quantifed approach that may or may not have anything to do with actual photography. Fair enough. To become happy one should do what makes one happy. If you are happy by basing your decision on impressions that may be influenced by a lot of factors and then are happy with the result of such a decision then that would be the right thing to do for you. To some people it is obvious that homoeopathy helps (beyond a placebo effect). Scientific approach, it is not. -- Yoda.

05-21-2009, 03:58 PM	#64
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by GoldenWreckedAngle Shutter lag at full auto focus: Canon 50D = 0.131 (W) seconds Pentax K20D = 0.174 (W) seconds Nikon D700 = 0.197 (W) seconds Canon 5D Mrk II = 0.206 (W) seconds Nikon D90 = 0.208 (W) seconds Nikon D300 = 0.227 (W) seconds Pentax K10D = 0.254 (W) seconds Ah, now I understand why everyone calls the K20D AF sluggish, sub-par, etc.................... NOT! When I was shopping for a DSLR (in late 2008) I read about Pentax AF being slow and was concerned about its applicability. When I first used it, I couldn't understand what people were on about. Maybe slower than competitors but no way slow in practical terms (fast action shooting aside). The above numbers tell me that even in relative terms, AF speed is more than sufficient at least when looked at from the relevant shutter lag perspective. Granted there might be some applications (very low light, fast moving action) where the Pentax AF still has room for improvement but I don't get the apparently common agreement about Pentax AF lacking in general.

05-21-2009, 04:03 PM	#65
asdf Veteran Member Join Date: Jan 2009 Location: Canada Posts: 1,252	Originally posted by Class A To some people it is obvious that homoeopathy helps (beyond a placebo effect). A homeopathic camera has a diluted 0MP sensor.

05-21-2009, 04:25 PM	#66
nosnoop Veteran Member Join Date: Feb 2007 Posts: 1,299	Originally posted by Wheatfield If you go out and use two different cameras, and one just seems to have snappier performance, then you've a qualified comparison that one camera is faster than the other. Not really. You would be surprised how much noise could influence your perception. For example, using one with USM lens may give you an impression it is a faster and more accurate simply because you cannot hear that the AF is working even if it takes just as long.

05-21-2009, 04:41 PM	#67
Ratmagiclady Veteran Member Join Date: Nov 2008 Location: GA Photos: Gallery \| Albums Posts: 13,563	Originally posted by Ray Pulley No it is already a waste of time. Ray Ok, yeah. Can't have anybody wasting any time... Here... on the Internet.

05-21-2009, 04:50 PM	#68
Ratmagiclady Veteran Member Join Date: Nov 2008 Location: GA Photos: Gallery \| Albums Posts: 13,563	Originally posted by Ray Pulley This was not about you and your feminine strengths or weaknesses. Get over yourself. BTW, how do you know I am a guy? Sort of presumptuous of you... Ray Actually, I didn't say you were, just that I'd had that experience. If you resemble it... draw your own conclusions, if it's not already clear.

05-21-2009, 05:05 PM	#69
Ratmagiclady Veteran Member Join Date: Nov 2008 Location: GA Photos: Gallery \| Albums Posts: 13,563	Originally posted by Clem Nichols Just to interject a comment here between the back-and-forth comments of Ray and the Ratmagiclady, an earlier poster in this thread mentioned that he had not seen anything mentioned about the speed of the K7's AF-C. Mark Dimalanta in his review reports that AF tracking in AF-C is "vastly improved". His review can be seen here: chasing light...: Initial Impressions of the Pentax K7 CN Anyway, yeah, I'm definitely more inclined to believe the guy who came up with the nicely-sharp surfer photos than people trying to theoretically-bash what they haven't used in the field, though one might well presume he has reason to have good feelings toward Pentax. Not sure what the deal about 'It's placebo effect' is supposed to be, though, what's gonna happen, someone come along and un-focus my photographs?

05-21-2009, 07:49 PM	#70
pingflood Veteran Member Join Date: Jun 2008 Location: Borås, Sweden Photos: Gallery Posts: 3,169	Originally posted by GoldenWreckedAngle The shutter lag at full auto focus is actually probably a more accurate number for real world shooting. This is kind of interesting: Shutter lag at full auto focus: Canon 50D = 0.131 (W) seconds Pentax K20D = 0.174 (W) seconds Nikon D700 = 0.197 (W) seconds Canon 5D Mrk II = 0.206 (W) seconds Nikon D90 = 0.208 (W) seconds Nikon D300 = 0.227 (W) seconds Pentax K10D = 0.254 (W) seconds Now go grab a D300 and a K20D and go do some actual shooting and see which one performs better. Honestly, I find it hard to believe that people claiming the K20D is as fast as or faster than the current prosumer cameras from the competition have ever shot with them. You can keep picking tests or setups that'll show an advantage, but in the end photography is done in the real world and that's where the true performance shows. The K20D is a very good, no a GREAT camera, but it doesn't smoke the competition in every area. You can keep trying to prove it does, or keep deluding yourself into believing so, but from somebody who's shot and handled a multitude of bodies going from ancient Leicas to viewcameras to current pro gear, IT AIN'T SO. Believe me, I didn't want to spend thousands more to get what I really wanted in a camera, but the difference was significant enough that I couldn't ignore it.

05-21-2009, 07:54 PM	#71
pingflood Veteran Member Join Date: Jun 2008 Location: Borås, Sweden Photos: Gallery Posts: 3,169	Originally posted by Ratmagiclady Eh, Golden. It'll do. What's that make the complainers, sitting around waiting on a difference of .04 seconds? I must be getting old. I think maybe why I'm tending to get a little peeved here is that it seems the message from all the, if you don't mind my saying, geekery, is, 'You can't unless you buy this, you can't unless you buy that.' That's no way to teach or learn photography. (So, sorry if it does cheese me off a little. I like talking about cameras, too. But I think there's a lot of loss of perspective about what really gets the job done involved. ) I think the whole "You can't" thing is a strawman conjured up by more than a few people. Honestly, how many people here are saying you _can't_ shoot birds in flight, car races, motocross, whatever with a Pentax DSLR or even a manual focus film body? What I see stated over and over again is that some other cameras make it EASIER to get the shots you want by doing what you ask them to well and rapidly. The world isn't black or white -- people actually ARE reasonable and present reasonable opinions and thoughts if you pay attention to what they're saying instead of lumping them into "pro" or "anti" categories. edit: and before somebody mocks "easy" as not-true-photography, go carry a freakin' 4x5 around everywhere or better yet go coat some plates and don't relly on the crutches of manufactured film/sensors. Or better yet, hole yourself up in a camera obscura and trace out your action shots on a wall, because you wouldn't want to rely on equipment to do the work for you. Then you can sit around and deride all the other pretend-photographers, the snapshooters, and complain about their obsession with gear and lack of real skills. edit2: not aimed towards you, Ratmagiclady, just an overall observation of common themes here lately...

05-21-2009, 07:57 PM	#72
dafiryde Veteran Member Join Date: Nov 2007 Location: Trinidad and Tobago Posts: 419	by chance do you think the original poster would reply , since he claimed to have an on hands experience with the K7 or was he BS Dave

05-21-2009, 10:36 PM	#74
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by Ray Pulley Really? See above..... I disagree with you. Let's leave it at that.

05-22-2009, 01:07 AM	#75
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521	Originally posted by Class A A phase detection system uses prisms (it works not unlike a split prism focusing screen). This causes a dependency on the wavelength. That is why Pentax AF front focuses under Tungsten light. The new sensor is responsible for detecting the light temperature and it's input is used to compensate the measurement of the phase detection system. At least that is my understanding. I agree that it sounds like that. I am wondering where this sensor is situated. Within the AF unit?