ABOUT PENTAX’S LONG STANDING AF ISSUE


senn

Link Posted 27/04/2015 - 18:33
IMHO, with K-5 (then K-5 IIs), Pentax has reached some apogee as for the IQ. That was the real step ahead after K-x. But, when Ricoh released K-3 I was expecting rather a K-5 “III” with significantly improved AF capabilities (speed and reliability) in order to set the brand able to compete in this realm too with some “others”. I don’t know how the famous SAFOX system has improved AF in Pentax bodies from K-5 II on, but honestly I don’t think it made things any significantly better than before. Does any bird or sport photographer note any significant AF improvement on Pentax DSLR from K-x till K-3 ? Unfortunately, Pentax was still (and will probably remain for a while) behind two “others” when it comes to AF performance. Instead, Ricoh seems to prefer to take pixels up. As for very new K-3 II, it’s equipped with a GPS system instead of pop up flash .. Hallelujah ! ☺ What do the very pentaxian (particularly those concerned by bird and sport photography) think of these choices ? Who cares whether Ricoh offers the best IQ quality camera in the market, or equipped with GPS or other gadgets, if it doesn’t prove an appropriate AF system in order to focus the subject properly with an acceptable rapidity and precision? Are things about to come to a better way with recently announced FF ? .. that would be a real revolution
senn
my flickr gallery
my PPG
Last Edited by senn on 27/04/2015 - 18:35

Mike-P

Link Posted 27/04/2015 - 18:56
I will be interested to see how the k-3II performs with the new 70-200mm and 150-450mm. In recent times the lack of AF speed has been blamed on the lenses (especially SDM) and it has been hinted that the new lenses are optimised for the K-3II autofocus algorithms.

From what I have read the new full frame camera will use the same autofocus module as the K-3II.
. My Flickr

Peter Elgar

Link Posted 27/04/2015 - 20:09
I am fed up with my K10D letting me down when I take photos in quick succession such as soccer action for local newspapers -- the photos are usually 'back-focused' -- now I use good 'ole Manual Focus' Recently was given three Minolta 'Dynax' film cameras, 3xi, 40 and the 5 -- well the auto -focus on those works perfectly -- NO back-focus -- I have today developed test from the Dynax 40 with different lenses -- all SHARP!
been a member of Pentax Club since the Ron Spillman era! Got COMPUTERISED at last - DIGITISED? Taken the PLUNGE - BUT FILM STILL RULES !!!

jeallen01

Link Posted 27/04/2015 - 20:41
Mike-P wrote:
I will be interested to see how the k-3II performs with the new 70-200mm and 150-450mm. In recent times the lack of AF speed has been blamed on the lenses (especially SDM) and it has been hinted that the new lenses are optimised for the K-3II autofocus algorithms..

This thread on the US forum gives some interesting pointers on how to set up the K-3 for improved AF performance - set mine up that way (I hope!) and will see how it does at the Abingdon Air & Country Fair this weekend (a very cheap airshow BTW!)
K-3 II, K-3 and a K-70 from SRS (having now relegated the K-30 /"K-50" to a backup body), & some Sigma and Pentax lenses (and a lot of old 35mm gear!)

richandfleur

Link Posted 27/04/2015 - 20:42
It was the continual missed focus that led me to sell my k100d
Old model for sure but you are right in this has been an issue for a while.

Pentax doesn't offer the number of focus points that the others do, being roughly half that of Nikon at last check.

I too would like to hear from k-3 owners own this topic, especially the tracking concept. Active tracking allows you to target an object and then have the camera follow the object, even if off centre on the edge of the frame. Mirrorless cameras do this impressively well as they now feature on sensor phase detection autofocus.
Last Edited by richandfleur on 27/04/2015 - 20:45

jeallen01

Link Posted 27/04/2015 - 20:46
richandfleur wrote:

I too would like to hear from k-3 owners own this topic, especially the tracking concept. Active tracking allows you to target an object and then have the camera follow the object, even if off centre on the edge of the frame.

Check the link I just posted.
K-3 II, K-3 and a K-70 from SRS (having now relegated the K-30 /"K-50" to a backup body), & some Sigma and Pentax lenses (and a lot of old 35mm gear!)

dcweather

Link Posted 27/04/2015 - 21:09
I am a dedicated Pentaxian but enough is enough! You cannot track a fairly slow flying bird against a blank sky with reliability. If you point it at the bird it will likely miss it first time then you have to look up to see where it is to get it back in the frame. You can do it - and I have got better at it but I have missed the moment so many times compared to my Canon mate standing next to me. You can be successful but if you lose focus it is difficult to get back. I have decided to find out for myself if there really is a big difference or if it is a case of the "grass is always greener" or my technique is rubbish. To that end I have bought a Nikon D5300 body and am able to borrow a Sigma 50-500mm to test it with which I am hopeful will be similar to my Sigma 150-500 on my K3 to compare - so watch this space.
Dave

richandfleur

Link Posted 27/04/2015 - 21:23
jeallen01 wrote:
richandfleur wrote:

I too would like to hear from k-3 owners own this topic, especially the tracking concept. Active tracking allows you to target an object and then have the camera follow the object, even if off centre on the edge of the frame.

Check the link I just posted.

Thanks, I posted this on the bus to work on a phone and missed your reply from a similar time.

This is the content I assume? (Thanks for the link):

I tried shooting BIF with AF Hold off, and the hit rate was terrible. I went to AF Hold LOW, but the camera still sometimes wandered off the subject in mid-sequence, so I went with MEDIUM on my last outing. After reading the Bumping Focus thread, I am definitely going with AF Hold HIGH now. I had only used AF High once, for a hockey game, and it was brilliant.

I also believe that for proper tracking, you need to use AF Expanded Area (i.e. not Auto AF 27 point, or Zone Auto 9 pt). "AF Expanded Area" allows you to pick the AF point, and tells the camera that whatever subject you initially focussed on, is to be tracked. I have had the best success with BIF and AF Expanded Area WIDE (27 points) for BIF, because they are very hard to follow, especially when close. I use AF Expanded Area SMALL (9 points) for sports.
Last Edited by richandfleur on 27/04/2015 - 21:32

richandfleur

Link Posted 27/04/2015 - 21:23
dcweather wrote:
so watch this space.
Dave

Will do.

Pjy123

Link Posted 28/04/2015 - 07:36
Hi i look forward to your findings dc weather! I use a k500 with a da55-300 lens and don't have much of a problem getting bird pics to be honest.

Blythman

Link Posted 28/04/2015 - 07:55
Awaiting your findings with anticipation Dave. Unlike Paul above, I do have difficulties getting bird pics. Its very frustrating
Alan


PPG
Flickr

jeallen01

Link Posted 28/04/2015 - 08:50
W.r.t. the link to the US forum, I was also referring to the posts on the second page from audiobomber and derekkite (and crewl1), notably:

"Originally posted by audiobomber Quote

Great shot. Now you see why I am so annoyed that DPR tested the K-3's AF with all the wrong settings, especially AF Hold OFF.

I'm not clear on which point selection you used, but I suspect it was Zone Auto 9 point? If so, please try AF Expanded Area SMALL next time. I prefer AF Expanded Area WIDE, but the main thing is, you want the Expanded Area active so the camera can track whichever point you initially selected.

What settings did you use for these? Like I said, I use Focus Priority, but I haven't tested the results from either.

16. First-Frame Action in AF-C
17. Action in AF-C Continuous shooting

AFC, expanded area 7. I think I will try bigger next time, but it worked quite well.

16 and 17 are focus priority.

I tried the standard dog running towards you test with single point and it didn't correct unless let go and pressed the AF button, this on 1.20. Earlier ones worked much better. I had found the expanded area not reliable for selecting the right point, but it seems much better now. I suspect that the hold 4 is the difference.

Read more at: http://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/293580-bif-comparison-da-300-vs-bigma-50-500-a-2.html#ixzz3YaVlmz8n"
K-3 II, K-3 and a K-70 from SRS (having now relegated the K-30 /"K-50" to a backup body), & some Sigma and Pentax lenses (and a lot of old 35mm gear!)

pgweber

Link Posted 28/04/2015 - 09:01
senn wrote:
As for very new K-3 II, it’s equipped with a GPS system instead of pop up flash .. Hallelujah ! ☺ What do the very pentaxian (particularly those concerned by bird and sport photography) think of these choices ? Who cares whether Ricoh offers the best IQ quality camera in the market, or equipped with GPS or other gadgets, if it doesn’t prove an appropriate AF system in order to focus the subject properly with an acceptable rapidity and precision?

Puts me in mind of:
Shop owner: Remarkable camera, the Pentax K3, Beautiful ergonomics!
Customer: The ergonomics don't enter into it. It can't focus.
Peter

Pentax K5
Pentax DA 18-55 Mk1, 50-200 (Samsung), 16-45, 55-300 Mk1, 35 f/2.4
Pentax MZ6 + FA28-90, FA50 f/1.4, M 50 f/1.7
Tamron 80-210mm & 28mm
Last Edited by pgweber on 28/04/2015 - 09:02

jeallen01

Link Posted 28/04/2015 - 11:00
Does it strike anyone that Ricoh could do us, AND itself, a BIG favour by posting on-line FAQs on how best to set the body up for various shooting scenarios - or have I missed something somewhere on their websites?
K-3 II, K-3 and a K-70 from SRS (having now relegated the K-30 /"K-50" to a backup body), & some Sigma and Pentax lenses (and a lot of old 35mm gear!)

senn

Link Posted 28/04/2015 - 12:40
jeallen01 wrote:
Does it strike anyone that Ricoh could do us, AND itself, a BIG favour by posting on-line FAQs on how best to set the body up for various shooting scenarios - or have I missed something somewhere on their websites?

Hi John. Thanks for taking part in this forum post. Your posts deserve interest.
Nevertheless, I don’t think RICOH needs any FAQ sequence to realize the “BIG” AF concern with Pentax DSLR bodies .. as I put in the title, this a too long standing issue. And, no one refutes that.

senn
my flickr gallery
my PPG
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