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03-03-2019, 03:35 PM   #16
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Presumably more focusing points mean more in-data for the AF algorithms. With good algorithms and fast hardware this should help with tracking.

I'm wondering about single point focus though. Can't be of much help there.

03-04-2019, 04:37 AM   #17
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QuoteOriginally posted by normhead Quote
Funny, cause the 55-300 solved a lot of my Pentax AF issues. I came at it a different way. I argued Pentax has always built lenses for the cameras they produced. The older slower AF lenses optimized for a K20D or older simply can't compare to a DA 55-PLM on a K-3 or later. Older lenses like the older DA*s were not even designed for AF as fast as the K-3/K-1 lenses.

Try out a DA 55-300 PLM and get back to me. We are talking about practical observations as opposed to theoretical constructs and assumptions. As I said, you don't know how good Pentax AF is until you try a DA 55-300 PLM on a K-P. Before that time, you're not even qualified to comment on the current state of Pentax and AF.

Norm

That is an interesting angle on this. In fact, certain SIGMA lenses seem to focus faster on newer bodies like the KP and K-1, that I can't figure out what the fuss is about. I also have several manual legacy lenses and with the camera in aperture mode, I can focus quickly with the excellent peaking function. To me the AF works well enough. I've said this before, I'm no engineer, but the ergonomics of the contemporary Pentax design fits my style of photography. Plus, from the K-10 all the way to the K-1, certain consistencies in the product design remain constant and picking up a newer model means a simpler learning curve.
03-04-2019, 12:49 PM   #18
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QuoteOriginally posted by steve_k Quote
Iím starting to see all these posts again about what the K-3II replacement should have. The number one thing seems to be more sensor points and faster and more accurate focus. This lead me to thinking about focus speed and accuracy. Isnít it the lens that is responsible for focus speed. I can see that the body would be responsible for the accuracy of auto focus but not the speed. Also the main recommendation I see for photo focusing is spot focusing. Not being an expert on this I assume that this would use only a few sensors max. So what good would more sensors provide for taking photos other than I hav more sensors than you. I can see where more sensors would be useful for continuous focus for moving objects and video. But I think that once you get above a certain number itís just a gimmick and no longer provides any advantage. Regarding focus accuracy I would guess that is more the algorithms used and light to determine focus accuracy than hundreds of sensor points. So maybe all Pentax needs are better focus algorithms in their software.

Just wondering if Im looking at this correctly or if my thinking is flawed.
Honestly, why do you care? The goal is fast and accurate AF and it is not on us to tell Pentax how to best achieve this goal - they know better than us anyways.

Lens speed, but also prediction algorithms as well as number and resolution/definition of AF points make a difference.
03-04-2019, 01:10 PM   #19
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QuoteOriginally posted by normhead Quote
Some actual facts for you

Full auto-focus Single area AF Pentax K-1 .09s

Canon 1Dx
Full auto-focus Single area AF .085s
This stat is impressive, but its on the K-1. How has Pentax been doing in this area before that? Seems to me they are just now catching up.
If you ignore the K-1 I think Docrwm has a point. What prior Pentax cameras are as good as their contemporaries?

03-06-2019, 05:06 PM   #20
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QuoteOriginally posted by Docrwm Quote
Bottom line, Pentax, by all non-fanboy accounts, still lags far behind in AF. My experience with working with Canon and Nikon shooters supports that contention.
@Docrwm, you've had some experience in comparing AF capabilities, which is important in these discussions. However, without suggesting that a full thesis is required, I think that it would be useful if your strong assertion could be reinforced by more details and insight into your comparisons.

As seen in several other current PF threads, it's difficult to understand the basis of these claims that Pentax AF is grossly inferior -- single-sentence accounts make it challenging for a reader to conclude the same thing, especially when there are other (published) accounts of apparently credible tests that conclude otherwise.

"Pentax... by all ... accounts, still lags far behind in AF." Is there a rationale to back this claim?

Thanks for any additional info you could lend.

- Craig
03-06-2019, 05:10 PM   #21
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QuoteOriginally posted by c.a.m Quote
@Docrwm, you've had some experience in comparing AF capabilities, which are important in these discussions. However, without suggesting that a full thesis is required, I think that it would be useful if your strong assertion could be reinforced by more details and insight into your comparisons.

As seen in several other current PF threads, it's difficult to understand the basis of these claims that Pentax AF is inferior -- single-sentence accounts make it challenging for a reader to conclude the same thing, especially when there are other (published) accounts of apparently credible tests that conclude otherwise.

"Pentax... by all ... accounts, still lags far behind in AF." Is there a rationale to back this claim?

Thanks for any additional info you could lend.

- Craig
Side-by-side with consumer Canon doing continuous AF on a soccer player at HS level - Canon has 8 shots all in perfect focus - Pentax K-3 has 3. High-5s among team members - Canon shoots 3 all in focus - Pentax gets 1. I'm tired of justifying the opinion that our AF is not up to Canon or Nikon standards. Funny but my opinion corresponds to all the pros and the reviewers statements. It's really simple - Pentax is seen by many as a Landscape and Portrait camera for several reasons but among them is the poorer AF responsiveness.
03-06-2019, 05:38 PM - 1 Like   #22
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QuoteOriginally posted by Docrwm Quote
I'm tired of justifying the opinion that our AF is not up to Canon or Nikon standards. Funny but my opinion corresponds to all the pros and the reviewers statements. It's really simple - Pentax is seen by many as a Landscape and Portrait camera for several reasons but among them is the poorer AF responsiveness.
It's just not true, Doc Ö here is the objective, repeatable testing:


How good is Pentax AF tracking? - PentaxForums.com
03-06-2019, 05:57 PM   #23
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QuoteOriginally posted by Docrwm Quote
Side-by-side with consumer Canon doing continuous AF on a soccer player at HS level - Canon has 8 shots all in perfect focus - Pentax K-3 has 3. High-5s among team members - Canon shoots 3 all in focus - Pentax gets 1.
Thanks for this example of two systems shooting side by side.

QuoteOriginally posted by Docrwm Quote
I'm tired of justifying the opinion that our AF is not up to Canon or Nikon standards.
Please don't take my questions offensively -- not asking for justification; just trying to understand the assertions that are frequently made, and trying to reconcile them with other anecdotes or images that show Pentax gear having very good AF performance. There doesn't seem to be consistency in this subject.


QuoteOriginally posted by Docrwm Quote
Funny but my opinion corresponds to all the pros and the reviewers statements.
Again, not trying to be difficult, but I'm not sure that "all the pros" have first hand experience in comparing Pentax with other systems. Could it be that some or many pros are regurgitating stuff that they've picked up? Maybe yes, maybe not, I don't know.


As for reviews and reviewers, a crux of the matter is the credibility of the reviews and their tests. We see some published tests that seem to be well designed, conducted, and reported. Conversely, I think there are reviews that are ill founded. Regardless, not all reviews or reports are unfavourable to Pentax AF.


Last edited by c.a.m; 03-06-2019 at 06:03 PM.
03-06-2019, 06:12 PM   #24
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QuoteOriginally posted by c.a.m Quote
Thanks for this example of two systems shooting side by side.

Please don't take my questions offensively -- not asking for justification; just trying to understand the assertions that are frequently made, and trying to reconcile them with other anecdotes or images that show Pentax gear having very good AF performance. There doesn't seem to be consistency in this subject.

Again, not trying to be difficult, but I'm not sure that "all the pros" have first hand experience in comparing Pentax with other systems. Could it be that some or many pros are regurgitating stuff that they've picked up? Maybe yes, maybe not, I don't know.

As for reviews and reviewers, a crux of the matter is the credibility of the reviews and their tests. We see some published tests that seem to be well designed, conducted, and reported. Conversely, I think there are reviews that are ill founded. Regardless, not all reviews or reports are unfavourable to Pentax AF.
I hear you. My problem is that no amount of information, experience, etc. will convince the fanboys. Heck , the much vaunted study that keeps getting referenced over and over and over again clearly shows that once the Pentax looses focus (which it does a LOT in low light) it never regains it, but the study is being flogged as somehow showing that Pentax AF is terrific.......
03-06-2019, 06:47 PM   #25
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QuoteOriginally posted by jack002 Quote
This stat is impressive, but its on the K-1. How has Pentax been doing in this area before that? Seems to me they are just now catching up.
If you ignore the K-1 I think Docrwm has a point. What prior Pentax cameras are as good as their contemporaries?
The 6 year old K-3 has the same stats. They were never better. I'm not going to argue Pentax is better at tracking. It's not. What I'm arguing is that for AF.s Pentax is faster and that includes for first frame capture. Why is this important? because I don't shoot soccer or sports. I shoot wildlife and nature. I have tracking set up in a user profile albelled BiF, I'v needed it twice and it worked both times. But there simply is no camera anywhere near it's price range that can match a K-3 or K-1 in AF.s. The Canon Nikon advantage applies only to tracking which is a fraction of a percent of what I and many others do. Docrwm, may shoot with tracking 100% of the time I don't know. But his comments are directed only at those who do.

It's odd, with no real competitors in their price range for AF.s, that people aren't going on about the others needing to catch up. Especially since anyone who shoots like me, AF.c tracking is irrelevant and works well enough when I need it. I've had my K-3 6 years, I needed it twice and would have used it if it was more reliable for wedding once. But I got along with my K-1. Not as good as Wonder does with his A9, but it got the job done.

Winder shoots a good number of weddings and he loves his A9. He'd be crazy to shoot with a K-1, and he's documented that. I've shot one wedding in the last 25 years, and I would have been crazy to buy an A9 for one job. It all depends on your perspective.

I suspect I've shot with more different Sony, Canon and Nikon shooters than Docrwm has, and I like my odds shooting Pentax. As I've stated many times, sometimes they get the best shot, sometimes I get the best shot. So my experience is different. Are you a sports shooter, or are you a landscape, natural macro, wildlife shooter? Unless you are a straight up sports shooter, you will probably find Pentax a better overall experience. It may let you down once or twice every 5 years, but for my shooting, it's never failed me.

I fail to understand why people are so adamant trashing Pentax AF. It doesn't deserve it's rep.
Shots like this depend on good quick accurate AF.s, and Pentax has that.



With the exception of 4 other cameras every one else lags far behind, many more tha double the AF.s focus lock, and no one's AF.c tracking lock is faster than Pentax's. AF.s Tracking focus lock requires double the speed of single point focus acquisition on even the best systems.

This day and many days, no one else got better, despite there being at least 4 Nikons, 3 canons and a Sony present.

Last edited by normhead; 03-06-2019 at 07:08 PM.
03-06-2019, 07:39 PM   #26
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Over the years I've posted many different cycling and football well focussed AF-C shots, whenever Pentax AF is discussed. I've had no issue with Pentax AF, except in very poor light.
03-06-2019, 07:51 PM   #27
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QuoteOriginally posted by normhead Quote
Funny, cause the 55-300 solved a lot of my Pentax AF issues. I came at it a different way. I argued Pentax has always built lenses for the cameras they produced. The older slower AF lenses optimized for a K20D or older simply can't compare to a DA 55-PLM on a K-3 or later. Older lenses like the older DA*s were not even designed for AF as fast as the K-3/K-1 lenses.

Try out a DA 55-300 PLM and get back to me. We are talking about practical observations as opposed to theoretical constructs and assumptions. As I said, you don't know how good Pentax AF is until you try a DA 55-300 PLM on a K-P. Before that time, you're not even qualified to comment on the current state of Pentax and AF.
I have the DA 55-300 PLM and I must admit that focus is almost instantaneous. I am not a technical guru and therefore would presume to even understand what goes on behind the lens and in the camera, but it seems to me that his lens on KS-2 is super speedy focusing, magical and sharp.
03-11-2019, 07:53 PM   #28
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QuoteOriginally posted by jack002 Quote
This stat is impressive, but its on the K-1. How has Pentax been doing in this area before that? Seems to me they are just now catching up.
If you ignore the K-1 I think Docrwm has a point. What prior Pentax cameras are as good as their contemporaries?
I think the KP more than holds its own in the AF department as well, particularly in low light. I applaud RICOH for tasking care of things that were lagging in a conscientious and evolutionary manner. The K-1 is fast, the KP is faster in lower light, even as an APS-c body. It pops. On a different thread REH tested the KP at 200,000 ISO. Guess what? the colors were steady and the image was discernible; the KP is a great little machine. I will also submit to you that the K-5ii series was also fast in lowlight for its day. I think some of the critique here is based on poor photographic technique or lack of experience by others unable to focus the old-fashioned way--manually. With focus peaking it's like having a full frame rangefinder....
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