K-5 II f/2.8 high-precision AF question

Anvh · 10-19-2012, 07:58 PM

The comment also said "in addition".

**jpzk** · 10-19-2012, 08:08 PM

So ... what's the final word (for AF "precision")?

For instance, will it be acurately useable with the DA*300/4 ? Will it make it more "acurate"? Will it make it worse?
Will it still work at F4 and "up" (f4.5, 5.6, etc...)

Really, what does this all mean in terms of usability with ANY lens?

JP

bwDraco · 10-19-2012, 08:18 PM

Originally posted by jpzk

So ... what's the final word (for AF "precision")?

For instance, will it be acurately useable with the DA*300/4 ? Will it make it more "acurate"? Will it make it worse?
Will it still work at F4 and "up" (f4.5, 5.6, etc...)

Really, what does this all mean in terms of usability with ANY lens?

JP

I have yet to hear back from Pentax, but lenses slower than f/2.8 should continue to focus without loss of functionality.

--DragonLord

Anvh · 10-19-2012, 08:23 PM

Originally posted by jpzk

So ... what's the final word (for AF "precision")?

For instance, will it be acurately useable with the DA*300/4 ? Will it make it more "acurate"? Will it make it worse?
Will it still work at F4 and "up" (f4.5, 5.6, etc...)

Really, what does this all mean in terms of usability with ANY lens?

JP

It depends on how it is implemented.

The f2.8 sensor would do nothing if very little for slower lenses so as long as non of the f/5.6 sensors are replaced it will do nothing negative for the focusing at least. Adding a f/8 sensor might be a nice idea to improve the speed but i doubt we would ever see that.
Most of the AF advancement is going in to sensor base focusing these days.

JinDesu · 10-19-2012, 08:36 PM

Thanks for the update - I hope you are correct, and I suspect Pentax wouldn't re-engineer their AF to cripple it in certain ways. As you said, it would be more intelligent to just add the F2.8 sensors in the format you proposed.

Anvh · 10-19-2012, 08:52 PM

Sorry for the double posts, i'm unable to edit my posts and the moderator approved them all

**jpzk** · 10-20-2012, 10:49 AM

Originally posted by DragonLord

I have yet to hear back from Pentax, but lenses slower than f/2.8 should continue to focus without loss of functionality.

--DragonLord

Originally posted by Anvh

It depends on how it is implemented.

The f2.8 sensor would do nothing if very little for slower lenses so as long as non of the f/5.6 sensors are replaced it will do nothing negative for the focusing at least. Adding a f/8 sensor might be a nice idea to improve the speed but i doubt we would ever see that.
Most of the AF advancement is going in to sensor base focusing these days.

Originally posted by Anvh

Sorry for the double posts, i'm unable to edit my posts and the moderator approved them all

Thanks for the info.

While I am waiting for my K5 to come back from Mississauga (Pentax Canada HQ) because of yet another repair, I browse this thread and became interested to know a bit more about this AF business with the K5II/IIs.
Not that I want to "upgrade" just yet, but I find this thread reather interesting to say the least.

Anything that would actually make the K5 AF more "acurate" and/or "precise" would be a huge bonus for me.

We shall then see how this comes down during the next few weeks once actual users got their hands on that camera.

Cheers.

JP

Anvh · 10-21-2012, 12:00 AM

Mhmm me too but it's quite a bit of money though for just an AF upgrade...
Hoping that Pentax has a camera in his bag above the K5.

With f/5.6 lenses you don't need to be as accurate as f/2.8 or faster so the extra accuracy is really appreciated there.

bwDraco · 10-23-2012, 01:44 PM

Just got this response from PENTAX in my personal email:

Quote:

Thank you for contacting PENTAX.

We have not received this specification for the center AF sensor type in the K-5ll and K-5lls from PENTAX Japan but our corporate office will make a request for this information. If PENTAX Japan provides us with this specification we will be happy to pass it along to you.

--DragonLord

Ayoh · 10-23-2012, 08:38 PM

https://www.pentaxforums.com/forums/pentax-k-5/203009-more-k-5ii-auto-focus-system-details.html

Class A · 10-24-2012, 01:16 AM

Originally posted by Anvh

Mhmm me too but it's quite a bit of money though for just an AF upgrade...

Well, there is the improved back LCD as well, and the (poor man's) AF tracking that shares AF sensors (as in the K-30).

Allegedly, there are more advantages, such as better JPG processing, but I'm not sure about these.

Originally posted by Anvh

Hoping that Pentax has a camera in his bag above the K5.

Expect a 24MP APS-C K-3 in early 2013.

Anvh · 10-25-2012, 10:37 AM

I shoot RAW, mostly manual focusing and almost never use the LCD screen, only for my settings or to quickly look at the histogram.
So... not for me.

Lets hope so, sound good.

froeschle · 10-26-2012, 01:24 PM

First tests of Beholder3 seem to indicate that the anticipated problems should at least be not as severe as expected: Test shots

**interested_observer** · 10-26-2012, 04:05 PM

Originally posted by Ayoh

https://www.pentaxforums.com/forums/pentax-k-5/203009-more-k-5ii-auto-focus-system-details.html

Here is something that Pentax could - and should produce a whitepaper on and post on their website. They did a public presentation on it - put it out for the rest of us.

bwDraco · 10-26-2012, 04:53 PM

Okay, it is now clear that the f/2.8 high-precision point is in addition to, not in lieu of, the existing AF sensors.

As such, Rice High's claim that the center point is disabled below f/2.8 is false. I feel Rice High often jumps to (mostly negative and incorrect) conclusions, rather than taking a closer look at the information--but we should also remember that he's not always wrong. As with anything, we should be critical of what we see on the Internet.

--DragonLord

10-24-2012, 01:16 AM	#41
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by Anvh Mhmm me too but it's quite a bit of money though for just an AF upgrade... Well, there is the improved back LCD as well, and the (poor man's) AF tracking that shares AF sensors (as in the K-30). Allegedly, there are more advantages, such as better JPG processing, but I'm not sure about these. Originally posted by Anvh Hoping that Pentax has a camera in his bag above the K5. Expect a 24MP APS-C K-3 in early 2013. Last edited by Class A; 10-24-2012 at 01:24 AM.

10-26-2012, 04:53 PM	#45
bwDraco Veteran Member Join Date: Jul 2010 Location: New York Photos: Albums Posts: 1,071 Original Poster	Okay, it is now clear that the f/2.8 high-precision point is in addition to, not in lieu of, the existing AF sensors. As such, Rice High's claim that the center point is disabled below f/2.8 is false. I feel Rice High often jumps to (mostly negative and incorrect) conclusions, rather than taking a closer look at the information--but we should also remember that he's not always wrong. As with anything, we should be critical of what we see on the Internet. --DragonLord Last edited by bwDraco; 10-26-2012 at 05:46 PM.

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10-19-2012, 07:58 PM	#31
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	The comment also said "in addition".

10-19-2012, 08:08 PM	#32
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251	So ... what's the final word (for AF "precision")? For instance, will it be acurately useable with the DA*300/4 ? Will it make it more "acurate"? Will it make it worse? Will it still work at F4 and "up" (f4.5, 5.6, etc...) Really, what does this all mean in terms of usability with ANY lens? JP

10-19-2012, 08:18 PM	#33
bwDraco Veteran Member Join Date: Jul 2010 Location: New York Photos: Albums Posts: 1,071 Original Poster	Originally posted by jpzk So ... what's the final word (for AF "precision")? For instance, will it be acurately useable with the DA*300/4 ? Will it make it more "acurate"? Will it make it worse? Will it still work at F4 and "up" (f4.5, 5.6, etc...) Really, what does this all mean in terms of usability with ANY lens? JP I have yet to hear back from Pentax, but lenses slower than f/2.8 should continue to focus without loss of functionality. --DragonLord

10-19-2012, 08:23 PM	#34
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by jpzk So ... what's the final word (for AF "precision")? For instance, will it be acurately useable with the DA*300/4 ? Will it make it more "acurate"? Will it make it worse? Will it still work at F4 and "up" (f4.5, 5.6, etc...) Really, what does this all mean in terms of usability with ANY lens? JP It depends on how it is implemented. The f2.8 sensor would do nothing if very little for slower lenses so as long as non of the f/5.6 sensors are replaced it will do nothing negative for the focusing at least. Adding a f/8 sensor might be a nice idea to improve the speed but i doubt we would ever see that. Most of the AF advancement is going in to sensor base focusing these days.

10-19-2012, 08:36 PM	#35
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Thanks for the update - I hope you are correct, and I suspect Pentax wouldn't re-engineer their AF to cripple it in certain ways. As you said, it would be more intelligent to just add the F2.8 sensors in the format you proposed.

10-19-2012, 08:52 PM	#36
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Sorry for the double posts, i'm unable to edit my posts and the moderator approved them all

10-20-2012, 10:49 AM	#37
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251	Originally posted by DragonLord I have yet to hear back from Pentax, but lenses slower than f/2.8 should continue to focus without loss of functionality. --DragonLord Originally posted by Anvh It depends on how it is implemented. The f2.8 sensor would do nothing if very little for slower lenses so as long as non of the f/5.6 sensors are replaced it will do nothing negative for the focusing at least. Adding a f/8 sensor might be a nice idea to improve the speed but i doubt we would ever see that. Most of the AF advancement is going in to sensor base focusing these days. Originally posted by Anvh Sorry for the double posts, i'm unable to edit my posts and the moderator approved them all Thanks for the info. While I am waiting for my K5 to come back from Mississauga (Pentax Canada HQ) because of yet another repair, I browse this thread and became interested to know a bit more about this AF business with the K5II/IIs. Not that I want to "upgrade" just yet, but I find this thread reather interesting to say the least. Anything that would actually make the K5 AF more "acurate" and/or "precise" would be a huge bonus for me. We shall then see how this comes down during the next few weeks once actual users got their hands on that camera. Cheers. JP

10-21-2012, 12:00 AM	#38
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Mhmm me too but it's quite a bit of money though for just an AF upgrade... Hoping that Pentax has a camera in his bag above the K5. With f/5.6 lenses you don't need to be as accurate as f/2.8 or faster so the extra accuracy is really appreciated there.

10-23-2012, 01:44 PM	#39
bwDraco Veteran Member Join Date: Jul 2010 Location: New York Photos: Albums Posts: 1,071 Original Poster	Just got this response from PENTAX in my personal email: Quote: Thank you for contacting PENTAX. We have not received this specification for the center AF sensor type in the K-5ll and K-5lls from PENTAX Japan but our corporate office will make a request for this information. If PENTAX Japan provides us with this specification we will be happy to pass it along to you. --DragonLord

10-23-2012, 08:38 PM	#40
Ayoh Veteran Member Join Date: Jun 2009 Location: Melbourne Posts: 341	https://www.pentaxforums.com/forums/pentax-k-5/203009-more-k-5ii-auto-focus-system-details.html

10-25-2012, 10:37 AM	#42
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	I shoot RAW, mostly manual focusing and almost never use the LCD screen, only for my settings or to quickly look at the histogram. So... not for me. Lets hope so, sound good.

10-26-2012, 01:24 PM	#43
froeschle Veteran Member Join Date: Sep 2007 Location: Germany Photos: Gallery Posts: 552	First tests of Beholder3 seem to indicate that the anticipated problems should at least be not as severe as expected: Test shots

10-26-2012, 04:05 PM	#44
interested_observer Loyal Site Supporter Join Date: Jun 2009 Location: Tumbleweed, Arizona Photos: Gallery \| Albums Posts: 5,707	Originally posted by Ayoh https://www.pentaxforums.com/forums/pentax-k-5/203009-more-k-5ii-auto-focus-system-details.html Here is something that Pentax could - and should produce a whitepaper on and post on their website. They did a public presentation on it - put it out for the rest of us.