AF confirm innacurate (confusion)

aliasant · 04-12-2011, 07:30 AM

Originally posted by Smeggypants

Yup did that a month ago.

Did it help?

Smeggypants · 04-12-2011, 07:33 AM

Originally posted by aliasant

Did it help?

Yup, certainly did. On my Original K-5 installing V1.03 made no difference to the low light front focussing fault. 1.03 on my replacement K-5 pretty much fixed it. I then bought a second K-5 a few days later and that is cool too.

the original K-5 was built in December 2010. The two I own now were built in Jan and Feb 2011

aliasant · 04-12-2011, 07:43 AM

Originally posted by Smeggypants

Yup, certainly did. On my Original K-5 installing V1.03 made no difference to the low light front focussing fault. 1.03 on my replacement K-5 pretty much fixed it. I then bought a second K-5 a few days later and that is cool too.

the original K-5 was built in December 2010. The two I own now were built in Jan and Feb 2011

nice!
You even got yourself a second K5

To me this just confirms that there is a hardware problem with SOME of the earlier builds. Same as the with the spots. For those that still dont believe us... go chase SantaClaus instead.

Smeggypants · 04-12-2011, 07:45 AM

Originally posted by aliasant

nice!
You even got yourself a second K5

To me this just confirms that there is a hardware problem with SOME of the earlier builds. Same as the with the spots. For those that still dont believe us... go chase SantaClaus instead.

Unfortunately on a public forum there isn't some kind of test to pass before joining

Rupert · 04-12-2011, 08:05 AM

I had a photo shoot yesterday and used a variety of lenses in MF and again found the focus indicator light and beep to be very accurate on every lens. On the DA*50-135, MF is just about as fast as AF, and at every range it was right on target with the indicator.
Here is one from the Nokton 58mm 1.4, a MF lens, using the focus indicator. Close enough for me!
I'm just guessing, that's all most of us do here, that some cameras may have a hardware problem that is causing inconsistent focus confirmation? If I had that problem, I would send it in for repair. I'm not sure I could live a day without my K5, so if I ever have to send mine in, I will order another one first, so I won't be "lonely" while it is in the shop.

Regards!
[IMG]

[/IMG]

JohnBee · 04-12-2011, 08:05 AM

Just to update this thread, I contacted Pentax and they told me to send the camera in. However, since I'm still within the exchange period, I think I'll just exchange it for another unit and see if things don't improve.

What I thought was really odd though, is that the Pentax support response team doesn't so much as answer questions as they issue the same generic response to everyone. (which kinda sucks).

Anyways, I'm going to try two other K-5's tomorrow at the store to see if they behave the same way. My issue at this stage isn't so much about trying to fix it as it is about trying to determine if this is common. I mean... what's the sense of sending-in a camera only to have it return the same way? - Hard to beleive, but it happens more often than I would have thought.

Smeggypants · 04-12-2011, 08:45 AM

Originally posted by Wheatfield

What you are saying is irrelevant to focusing, which is not the same as judging depth of field. Why don't you get that?

Right so now you're been proven wrong you're not saying it's horsepoo , i.e a thinly veiled admission I was correct we now get onto the issue of how relevant this is to focussing.

I actually have an F/1.2 and because the focus screen shows a wider DOF than is reality it's easy to think the lens is in focus when it isn't.

This is why I try wherever possible to use the Live view and look at the subject through the sensor ( and magnified ) to achieve correct focus

You've read this post I take it ?

Originally posted by NaClH2O:

Christine, I have to agree with you. I can't speak for the K-5, but I have owned/own DS, K10D, K20D and K-x. on all of those cameras, the apparent DOF in the viewfinder has been/is wider than the actual DOF as captured by the sensor. IIRC, this was true of my ZX-5N film camera as well. This has been commented on multiple times in these forums if not elsewhere. I had thought this was common knowledge, but obviously not. That is not to say I can't focus precisely, but just that you have to be careful with wide apertures.

Sometimes jumping in and calling 'Horsepoo' is unwise before actually checking

You ask "Why don't you get that?" - Well becuase the DOF we see is highly relevant to focussing accuracy by eye. Why don't you get that?

Smeggypants · 04-12-2011, 08:49 AM

Nice pic Rupert.

Originally posted by Rupert

I'm just guessing, that's all most of us do here, that some cameras may have a hardware problem that is causing inconsistent focus confirmation? If I had that problem, I would send it in for repair. I'm not sure I could live a day without my K5, so if I ever have to send mine in, I will order another one first, so I won't be "lonely" while it is in the shop.

It's possible that the camera is the culprit in some cases, but my A50/1.2 and A50/1.2 have not had accurate focus confirmation on all Pentax DSLRs I have owned and own. That's a K10D,a K20D and three K-5s

I'd say the lenses were the culprits in that case. The A50/1.2 requires a setting way over the allowed +/- 10 on the focus adjustment so I the oly way I can get accurate focus at 1.2 is to use LV through the sensor. The focus screen doesn't resolve the DOF @ 1.2 apertures

rhodopsin · 04-12-2011, 09:11 AM

Supposedly, the DOF seen in viewfinder is the same as seen in 8x10" print held at arms length. Print smaller, or view farther away, the apparent DOF increases. Print larger, or view closer, the apparent DOF decreases. (I would love to put numbers into equations, but my optics knowledge is lacking, I can't figure how to determine the size of the virtual image seen in viewfinder -- that is required in the equations and calculations I know about)

Physics verifies that the angle of rays of light from the outer portion of the front lens surface is too great for fresnel lines of focus screen to bend into viewfinder. These outer rays are the faster portions of the light the lens sees -- remember as diameter of entrance aperture increases, f/# decreases. A fresnel focus screen with finer lines is necessary.

Pentax cameras have excellent viewfinders and focus screens. I do not know about stock Pentax focus screens, if they are fresnel, if the lines are small enough to see focus at wide apertures. I do know the Canon focus screens are fresnel and the stock screen cannot show DOF below f/3.5 -- Canon sells 'faster' focus screens, the caveat is the viewfinder quickly goes quite dark if lens is stopped more than f/3.5. Even wheatfield is using a stock focus screen replacement...so I think the physics apply to Pentax screens too.

opiedog · 04-12-2011, 09:34 AM

Originally posted by joe.penn

rhodopsin, I tried what you typed (quoted above), and I ran into something interesting. While backing down the focus from infinity to get the shot into focus, the "focused indicator (green)" would beep in, as it should when the subject is in focus - this is the weird thing, as soon as it beeped in, I would start slowly turning the focus back up (back to infinity), it would take almost a 1/4 turn of the focus ring before the focus indicator would go back off to indicate "out of focus", but i could clearly see that the subject was clearly out of focus long before the indicator indicated it.

Using 50mm 1.7, center focusing while doing this test. Does this not sound odd? The camera exhibited this behavior every time I tried this...

i noticed the same behavior with on my *istDL, K10, km and kx and this was with an AF zoom set to MF.

apparently, the green hexagon + beep has a lot of "wiggle room". not sure if this was due to the AF module or the lens being in MF, but it was frustrating, to say the least.

aliasant · 04-12-2011, 10:00 AM

Originally posted by Wheatfield

Seriously, learn how to manual focus. People did it for decades prior to AF cameras, and we did it with fast lenses.

Seriously. You still dont get it.

Smeg had problems with his first k5. After replacing that with a new one his problems are gone.

Same story with me.
I just got my replacement k5 today. My first had spots so Pentax exchanged it without any questions. My new k5 is spotfree and I have no focusing problems anymore.
Im only using manual lenses. I dont even own one with AF.

Read this carefully and try to let it sink in.

SOME of the K5s made last year do have a problem with FF, spots and what nots. NOT ALL has those problems.

After Smeg got a replacement his problems are gone.
After I got my new K5 my problems are gone.

Smeggypants · 04-12-2011, 10:05 AM

Originally posted by Wheatfield

I'm not sure where you are getting this, and you seem more interested in scoring internet debating points than anything else.
Accept that I have no problems accurately focusing a 50mm f/1.2 lens and you do have problems.
All you are saying, in a roundabout way, is that I have a better skill set than you.
And remember, winning a debate on the net is like winning gold at the special Olympics. Consider the gold medal yours.

And you are back onto my ignore list.

ROFLMAO

Originally posted by Wheatfield

you seem more interested in scoring internet debating points than anything else.

That I can see is your agenda not mine. Unfortunately in your attempt to take prizepoints in this thread with your trigger happy Horse poo put down of the commonly know DOF issues with focussing screens you have been called out and several people have posted confirmations you were wrong. Again.

Smeggypants · 04-12-2011, 10:08 AM

Originally posted by Wheatfield

This might be due to the DOF limitations that smeg is talking about, which may well exist in the AF system. It would account for a lot of the AF inaccuracy complaints that I've had over the years, where the AF just doesn't quite hit the nail on the head.

You've had complaints? Why would peoplehold you accountable for AF problems

Quote:

Seriously, learn how to manual focus. People did it for decades prior to AF cameras, and we did it with fast lenses.

Most patronising. AF didn't exist when I started snapping

Smeggypants · 04-12-2011, 10:10 AM

Originally posted by aliasant

Seriously. You still dont get it.

Smeg had problems with his first k5. After replacing that with a new one his problems are gone.

Same story with me.
I just got my replacement k5 today. My first had spots so Pentax exchanged it without any questions. My new k5 is spotfree and I have no focusing problems anymore.
Im only using manual lenses. I dont even own one with AF.

Read this carefully and try to let it sink in.

SOME of the K5s made last year do have a problem with FF, spots and what nots. NOT ALL has those problems.

After Smeg got a replacement his problems are gone.
After I got my new K5 my problems are gone.

Those who already think they know everything are reluctant to learn.

JohnBee · 04-12-2011, 10:12 AM

Originally posted by Smeggypants

It's possible that the camera is the culprit in some cases, but my A50/1.2 and A50/1.2 have not had accurate focus confirmation on all Pentax DSLRs I have owned and own. That's a K10D,a K20D and three K-5s

I'd say the lenses were the culprits in that case. The A50/1.2 requires a setting way over the allowed +/- 10 on the focus adjustment so I the oly way I can get accurate focus at 1.2 is to use LV through the sensor. The focus screen doesn't resolve the DOF @ 1.2 apertures

Hi Smeggypants,

Did you happen to noticed if/when AF confirm began to jive along the aperture scale? I don't have a 1.2 but I do own two 1.4 lenses and my test confirm that they begin to enter accuracy at/or around 2.8.

However, on an AF lens, I can MF perfectly at 1.4! - And so I'm guessing that the AF system implements some "sort of" focus correction measure to cope with wider apertures. Though this doesn't happen with none Pentax or... lenses that can't be identified by the system.

Would be very cool to get more feedback on this hypothesis based on experiences from others.

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04-12-2011, 07:30 AM	#46
aliasant Veteran Member Join Date: Feb 2010 Location: Stockholm Photos: Gallery \| Albums Posts: 634	Originally posted by Smeggypants Yup did that a month ago. Did it help?

04-12-2011, 07:33 AM	#47
Smeggypants Veteran Member Join Date: Sep 2010 Posts: 1,536	Originally posted by aliasant Did it help? Yup, certainly did. On my Original K-5 installing V1.03 made no difference to the low light front focussing fault. 1.03 on my replacement K-5 pretty much fixed it. I then bought a second K-5 a few days later and that is cool too. the original K-5 was built in December 2010. The two I own now were built in Jan and Feb 2011

04-12-2011, 07:43 AM	#48
aliasant Veteran Member Join Date: Feb 2010 Location: Stockholm Photos: Gallery \| Albums Posts: 634	Originally posted by Smeggypants Yup, certainly did. On my Original K-5 installing V1.03 made no difference to the low light front focussing fault. 1.03 on my replacement K-5 pretty much fixed it. I then bought a second K-5 a few days later and that is cool too. the original K-5 was built in December 2010. The two I own now were built in Jan and Feb 2011 nice! You even got yourself a second K5 To me this just confirms that there is a hardware problem with SOME of the earlier builds. Same as the with the spots. For those that still dont believe us... go chase SantaClaus instead.

04-12-2011, 07:45 AM	#49
Smeggypants Veteran Member Join Date: Sep 2010 Posts: 1,536	Originally posted by aliasant nice! You even got yourself a second K5 To me this just confirms that there is a hardware problem with SOME of the earlier builds. Same as the with the spots. For those that still dont believe us... go chase SantaClaus instead. Unfortunately on a public forum there isn't some kind of test to pass before joining

04-12-2011, 08:05 AM	#50
Rupert Veteran Member Join Date: Sep 2006 Location: Texas Photos: Gallery \| Albums Posts: 25,123	I had a photo shoot yesterday and used a variety of lenses in MF and again found the focus indicator light and beep to be very accurate on every lens. On the DA*50-135, MF is just about as fast as AF, and at every range it was right on target with the indicator. Here is one from the Nokton 58mm 1.4, a MF lens, using the focus indicator. Close enough for me! I'm just guessing, that's all most of us do here, that some cameras may have a hardware problem that is causing inconsistent focus confirmation? If I had that problem, I would send it in for repair. I'm not sure I could live a day without my K5, so if I ever have to send mine in, I will order another one first, so I won't be "lonely" while it is in the shop. Regards! [IMG] [/IMG]

04-12-2011, 08:05 AM	#51
JohnBee Veteran Member Join Date: Sep 2008 Location: Newrfoundland Photos: Albums Posts: 4,667 Original Poster	Just to update this thread, I contacted Pentax and they told me to send the camera in. However, since I'm still within the exchange period, I think I'll just exchange it for another unit and see if things don't improve. What I thought was really odd though, is that the Pentax support response team doesn't so much as answer questions as they issue the same generic response to everyone. (which kinda sucks). Anyways, I'm going to try two other K-5's tomorrow at the store to see if they behave the same way. My issue at this stage isn't so much about trying to fix it as it is about trying to determine if this is common. I mean... what's the sense of sending-in a camera only to have it return the same way? - Hard to beleive, but it happens more often than I would have thought.

04-12-2011, 08:45 AM	#52
Smeggypants Veteran Member Join Date: Sep 2010 Posts: 1,536	Originally posted by Wheatfield What you are saying is irrelevant to focusing, which is not the same as judging depth of field. Why don't you get that? Right so now you're been proven wrong you're not saying it's horsepoo , i.e a thinly veiled admission I was correct we now get onto the issue of how relevant this is to focussing. I actually have an F/1.2 and because the focus screen shows a wider DOF than is reality it's easy to think the lens is in focus when it isn't. This is why I try wherever possible to use the Live view and look at the subject through the sensor ( and magnified ) to achieve correct focus You've read this post I take it ? Originally posted by NaClH2O: Christine, I have to agree with you. I can't speak for the K-5, but I have owned/own DS, K10D, K20D and K-x. on all of those cameras, the apparent DOF in the viewfinder has been/is wider than the actual DOF as captured by the sensor. IIRC, this was true of my ZX-5N film camera as well. This has been commented on multiple times in these forums if not elsewhere. I had thought this was common knowledge, but obviously not. That is not to say I can't focus precisely, but just that you have to be careful with wide apertures. Sometimes jumping in and calling 'Horsepoo' is unwise before actually checking You ask "Why don't you get that?" - Well becuase the DOF we see is highly relevant to focussing accuracy by eye. Why don't you get that?

04-12-2011, 08:49 AM	#53
Smeggypants Veteran Member Join Date: Sep 2010 Posts: 1,536	Nice pic Rupert. Originally posted by Rupert I'm just guessing, that's all most of us do here, that some cameras may have a hardware problem that is causing inconsistent focus confirmation? If I had that problem, I would send it in for repair. I'm not sure I could live a day without my K5, so if I ever have to send mine in, I will order another one first, so I won't be "lonely" while it is in the shop. It's possible that the camera is the culprit in some cases, but my A50/1.2 and A50/1.2 have not had accurate focus confirmation on all Pentax DSLRs I have owned and own. That's a K10D,a K20D and three K-5s I'd say the lenses were the culprits in that case. The A50/1.2 requires a setting way over the allowed +/- 10 on the focus adjustment so I the oly way I can get accurate focus at 1.2 is to use LV through the sensor. The focus screen doesn't resolve the DOF @ 1.2 apertures

04-12-2011, 09:11 AM	#54
rhodopsin Veteran Member Join Date: Dec 2009 Location: Deep Forest Posts: 643	Supposedly, the DOF seen in viewfinder is the same as seen in 8x10" print held at arms length. Print smaller, or view farther away, the apparent DOF increases. Print larger, or view closer, the apparent DOF decreases. (I would love to put numbers into equations, but my optics knowledge is lacking, I can't figure how to determine the size of the virtual image seen in viewfinder -- that is required in the equations and calculations I know about) Physics verifies that the angle of rays of light from the outer portion of the front lens surface is too great for fresnel lines of focus screen to bend into viewfinder. These outer rays are the faster portions of the light the lens sees -- remember as diameter of entrance aperture increases, f/# decreases. A fresnel focus screen with finer lines is necessary. Pentax cameras have excellent viewfinders and focus screens. I do not know about stock Pentax focus screens, if they are fresnel, if the lines are small enough to see focus at wide apertures. I do know the Canon focus screens are fresnel and the stock screen cannot show DOF below f/3.5 -- Canon sells 'faster' focus screens, the caveat is the viewfinder quickly goes quite dark if lens is stopped more than f/3.5. Even wheatfield is using a stock focus screen replacement...so I think the physics apply to Pentax screens too.

04-12-2011, 09:34 AM	#55
opiedog Inactive Account Join Date: Jan 2008 Location: NC Posts: 787	Originally posted by joe.penn rhodopsin, I tried what you typed (quoted above), and I ran into something interesting. While backing down the focus from infinity to get the shot into focus, the "focused indicator (green)" would beep in, as it should when the subject is in focus - this is the weird thing, as soon as it beeped in, I would start slowly turning the focus back up (back to infinity), it would take almost a 1/4 turn of the focus ring before the focus indicator would go back off to indicate "out of focus", but i could clearly see that the subject was clearly out of focus long before the indicator indicated it. Using 50mm 1.7, center focusing while doing this test. Does this not sound odd? The camera exhibited this behavior every time I tried this... i noticed the same behavior with on my *istDL, K10, km and kx and this was with an AF zoom set to MF. apparently, the green hexagon + beep has a lot of "wiggle room". not sure if this was due to the AF module or the lens being in MF, but it was frustrating, to say the least.

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04-12-2011, 10:00 AM	#56
aliasant Veteran Member Join Date: Feb 2010 Location: Stockholm Photos: Gallery \| Albums Posts: 634	Originally posted by Wheatfield Seriously, learn how to manual focus. People did it for decades prior to AF cameras, and we did it with fast lenses. Seriously. You still dont get it. Smeg had problems with his first k5. After replacing that with a new one his problems are gone. Same story with me. I just got my replacement k5 today. My first had spots so Pentax exchanged it without any questions. My new k5 is spotfree and I have no focusing problems anymore. Im only using manual lenses. I dont even own one with AF. Read this carefully and try to let it sink in. SOME of the K5s made last year do have a problem with FF, spots and what nots. NOT ALL has those problems. After Smeg got a replacement his problems are gone. After I got my new K5 my problems are gone.

04-12-2011, 10:05 AM	#57
Smeggypants Veteran Member Join Date: Sep 2010 Posts: 1,536	Originally posted by Wheatfield I'm not sure where you are getting this, and you seem more interested in scoring internet debating points than anything else. Accept that I have no problems accurately focusing a 50mm f/1.2 lens and you do have problems. All you are saying, in a roundabout way, is that I have a better skill set than you. And remember, winning a debate on the net is like winning gold at the special Olympics. Consider the gold medal yours. And you are back onto my ignore list. ROFLMAO Originally posted by Wheatfield you seem more interested in scoring internet debating points than anything else. That I can see is your agenda not mine. Unfortunately in your attempt to take prizepoints in this thread with your trigger happy Horse poo put down of the commonly know DOF issues with focussing screens you have been called out and several people have posted confirmations you were wrong. Again.

04-12-2011, 10:08 AM	#58
Smeggypants Veteran Member Join Date: Sep 2010 Posts: 1,536	Originally posted by Wheatfield This might be due to the DOF limitations that smeg is talking about, which may well exist in the AF system. It would account for a lot of the AF inaccuracy complaints that I've had over the years, where the AF just doesn't quite hit the nail on the head. You've had complaints? Why would peoplehold you accountable for AF problems Quote: Seriously, learn how to manual focus. People did it for decades prior to AF cameras, and we did it with fast lenses. Most patronising. AF didn't exist when I started snapping

04-12-2011, 10:10 AM	#59
Smeggypants Veteran Member Join Date: Sep 2010 Posts: 1,536	Originally posted by aliasant Seriously. You still dont get it. Smeg had problems with his first k5. After replacing that with a new one his problems are gone. Same story with me. I just got my replacement k5 today. My first had spots so Pentax exchanged it without any questions. My new k5 is spotfree and I have no focusing problems anymore. Im only using manual lenses. I dont even own one with AF. Read this carefully and try to let it sink in. SOME of the K5s made last year do have a problem with FF, spots and what nots. NOT ALL has those problems. After Smeg got a replacement his problems are gone. After I got my new K5 my problems are gone. Those who already think they know everything are reluctant to learn.

04-12-2011, 10:12 AM	#60
JohnBee Veteran Member Join Date: Sep 2008 Location: Newrfoundland Photos: Albums Posts: 4,667 Original Poster	Originally posted by Smeggypants It's possible that the camera is the culprit in some cases, but my A50/1.2 and A50/1.2 have not had accurate focus confirmation on all Pentax DSLRs I have owned and own. That's a K10D,a K20D and three K-5s I'd say the lenses were the culprits in that case. The A50/1.2 requires a setting way over the allowed +/- 10 on the focus adjustment so I the oly way I can get accurate focus at 1.2 is to use LV through the sensor. The focus screen doesn't resolve the DOF @ 1.2 apertures Hi Smeggypants, Did you happen to noticed if/when AF confirm began to jive along the aperture scale? I don't have a 1.2 but I do own two 1.4 lenses and my test confirm that they begin to enter accuracy at/or around 2.8. However, on an AF lens, I can MF perfectly at 1.4! - And so I'm guessing that the AF system implements some "sort of" focus correction measure to cope with wider apertures. Though this doesn't happen with none Pentax or... lenses that can't be identified by the system. Would be very cool to get more feedback on this hypothesis based on experiences from others.