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04-06-2017, 11:40 AM   #31
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QuoteOriginally posted by normhead Quote
Am I missing something, or has there been a bunch of bull poop passed off as fact on this and many other forums?
Yes, you are missing something key. Pentax lenses not being optically stabilized, user skills for tracking and beside speed of first focus, you are missing AF tracking speed of the camera algorithm.
My experience with Pentax K1 and DFA150450 or DFA70-200 or other DFA is the following:
- the speed of a full AF run from infinity to nearest focus (or vice versa) is way faster than the speed of most subject, with my DFA150450, focus from 100 meters to 2m is done is less than 0.5 sec (or less). that's about 200m/s = 447 miles per hour !
- when the subject motion is not straight or erratic, it is very hard for me to keep the subject inside the viewfinder under the zone of AF points, if I can't keep the subject steady enough in the view finder, the camera lose focus.
- usually, in AFC mode, the first shot is often in better focus than the two subsequent shots, which means that the camera is very fast to reach target and then fails to update focus fast enough is the subject motion is erratic.

I believe that if I completely miss shots because the subject is too fast for the Pentax AF, i'll also miss the same shot with a Canon or Nikon because my problem is my ability to keep the camera and lens pointed to the fast moving subject. It's only in intermediate situations that the Canon or Nikon will give me more keepers. So, yeah, Pentax AF is annoying as are other AF system.. and to take benefit of faster AF tracking of other brands will help in less than 10% of shooting situations. If I'd be doing only sports photos, then of course, a faster AF tracking would favor other brand vs Pentax. The thing is, having less keepers is not a big deal as I often have too many good photos, blurred shots make decisions to delete easier.

04-06-2017, 11:56 AM   #32
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QuoteOriginally posted by monochrome Quote
Norm, please stop speaking truth to power. If you change the perception of Pentax AF all those Canon whiners will come over here and make us miserable.
That's what the Ignore button is for...
04-06-2017, 11:56 AM   #33
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Yes, you are missing something key. Pentax lenses not being optically stabilized, user skills for tracking and beside speed of first focus, you are missing AF tracking speed of the camera algorithm.
I think you missed my point, we are talking AF speed here. Tracking is a different topic, Most of us will concede Pentax tracking is not as good. But very few if any have quantified that. We know it might be bad for Pentax, but we want to know how bad. OK, like a Pentax shooter and a Nikon or Canon shooter go out together. At the end of the day, what's the difference? What percentage of our images are affected? Now that would be something we could sink our teeth into. For me, I have the 5 -10 shots i went for, don't care if i don't have 11-15. I don't even know those are real numbers. Surely it would be up to those making these claims about the advantages of the AF of other systems to substantiate in some way those claims.

For years I heard about the wonderful advantages of FF as a format, and I've largely been able to refute almost all of them since acquiring a K-1. It's better for maybe 5% of my shots, which is what i always estimated. Yet i took all kinds of abuse for saying that. I couldn't know because i didn't own a full frame camera to see how wonderful it was.. How do I know talking AF isn't the same? I'm not buying a 1DX just to prove a bunch of loudmouths wrong.

Look at the possible situations...
1. MF works fine.
2. Pentax AF-c tracking works fine.
3. Pentax tracking doesn't work fine but Canon or Nikon does.
4. No AF works at all. Subject is too fast.

We have an awful lot of shooters trying to convince us they make their living in zone 3. How about a little statistical analysis to support that opinion?

Someone should point me to these sites where they have all the Canon and Nikon images that couldn't have possibly have been taken with a Pentax. Following the club
The 300mm plus lens Club discuss your long lenses. - Page 1680 - PentaxForums.com,
it has a lot of pictures that you would assume were taken with gear from different manufacturers based on the criticism of Pentax AF. How are they getting these images if it's so bad?

Last edited by normhead; 04-06-2017 at 12:08 PM.
04-06-2017, 01:01 PM - 2 Likes   #34
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Pentax af-c tracking sistem need a lot of time to learn and practice to get good pictures. Default settings from factory doesnot help us. But When settings are well done and you are good trainned I think is as good as other se sistems. I use k3 with bigma and F 300 .

https://flic.kr/p/Mrad94

04-06-2017, 06:02 PM - 1 Like   #35
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QuoteOriginally posted by stevebrot Quote
I have puzzled over these numbers on IR for a couple of years now. What they mean is not very clear and how they are arrived at is even less clear. The intent is to measure camera responsiveness, of which AF speed is only one component. In short, they are NOT measuring AF speed, at least not directly or in any comprehensive way.
I think responsiveness is exactly it. The numbers in the OP have nothing to do with how quickly the camera can spin the focus ring and lock on to a target. We've been through this before, and it's just misleading that these numbers are being paraded around again like they means anything at all to AF speed:

Slow Pentax AF.... ha, eat my shorts - PentaxForums.com

Again, the K-1 results on IR:

Pentax K-1 Review - Performance

and below the chart (which is titled "Shutter Response (Lag Time), Optical Viewfinder") is the text:

To minimize the effect of different lens' focusing speed, we test AF-active shutter lag with the lens already set to the correct focal distance.
04-06-2017, 06:59 PM   #36
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QuoteOriginally posted by BrianR Quote
To minimize the effect of different lens' focusing speed, we test AF-active shutter lag with the lens already set to the correct focal distance.
They are measuring the time it takes for the AF system to initialize and confirm as part of the full sequence. I had forgotten that disclaimer, but now that bring it up, the whole thing falls into place.

In defense of Norm, it is easy to assume that the tables mean what they say at face value. I also agree that Pentax AF has been painted as being unusually poor despite many users getting quite good results. I don't do birds in flight (too impoverished to afford the glass), but sometimes do events and have been generally please with the AF ability to deal with dancers and such.


Steve

Last edited by stevebrot; 04-06-2017 at 07:07 PM.
04-07-2017, 01:55 AM - 1 Like   #37
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QuoteOriginally posted by normhead Quote
Someone should point me to these sites where they have all the Canon and Nikon images that couldn't have possibly have been taken with a Pentax. Following the club
The 300mm plus lens Club discuss your long lenses. - Page 1680 - PentaxForums.com,
it has a lot of pictures that you would assume were taken with gear from different manufacturers based on the criticism of Pentax AF. How are they getting these images if it's so bad?
Here is something I can't believe that you'll do with a Pentax camera: shooting 7 continuous images with a Kingfisher in flight (I assume you know how erratic is their flight). This guy is a proffessional photographer. Getting one image here, two images there with chaotic birds can be done with almost any camera released in the last 3 years, but proffesionals are looking for this type of af (fast and precise). Why? Because they don't shoot birds on the branches, prefocusing and relying on manual focus and also on the DOF. They publish images with stories behind them in international magazines, images that require speed and precision. They're not interested in the number of megapixels.

Yes, Pentax has decent af for a lot of situations and for occasional BIF it's ok, but stop comparing Pentax K1 and K3 with 1Dx or D5/D500 because they are so different that even a child can see the differences.

04-07-2017, 02:57 AM - 2 Likes   #38
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WOW this Pentax AF performance controversy has spread in PF like an infectious disease!

I don't care what it is written any more. I have tried many systems and specific cameras and made up my mind. Long story short, there is nothing out there today that beats the D500 in the AF speed, consistency and tracking department (far better than 7DII). It also has great IQ for an APS-C camera. BUT! There is always a but...

We are talking about the AF tracking performance of the Pentax cameras under difficult situations and for fast action purposes (like a small bird flying in a busy background e.g inside a forest).

For what reason? Is there any long and fast lens that could be used in such a situation with a Pentax K-3 or a K-1? Nothing besides the short DFA 70-200/2.8 zoom. The DFA 150-450 is only 5.6 at the long end, so can't match 2.8 primes or even the 200-400/4 zooms from Canonikon... The only contemporary tele lens is the DA 560 that is 5.6 and focuses so slow which also excludes it from such a test...

So, what's the point of this conversation? It will be interesting and meaningful when Pentax decides to enter this fast action - sport category by releasing equipment that could fall under this category.

Until then I don't care what someone with a D5, D500, 7DII or even a D7200 can achieve with a 500/4 or 400/2.8 or 200-400/4 zoom. It is irrelevant! There is no space for comparisons.

04-07-2017, 03:29 AM   #39
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QuoteOriginally posted by redpit Quote
Until then I don't care what someone with a D5, D500, 7DII or even a D7200 can achieve with a 500/4 or 400/2.8 or 200-400/4 zoom. It is irrelevant! There is no space for comparisons.
Except the fact that the images from above were taken with a Nikon 300mmf4 lens and 1.4x TC.
04-07-2017, 03:33 AM - 1 Like   #40
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I wonder how many would buy a new Pentax APS-C flagship with much-improved AF, if it would cost 2000 euro.
I wonder how many would buy a Pentax lens with a 5-digit price... in euro.
I wonder how many here would shoot kingfishers as well as Mircea Bezergheanu. I know I can't, regardless of which camera I'd be using.
04-07-2017, 03:47 AM   #41
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QuoteOriginally posted by Dan Rentea Quote
Except the fact that the images from above were taken with a Nikon 300mmf4 lens and 1.4x TC.
No this is irrelevant too. Otherwise you have to accept that these kind of shots could be taken with a MF lens also. What matters is that Nikon has developed a whole system oriented towards fast action and sport photography. The D300s had great AF and was super fast but with the super fast focusing lenses. It's up to you then to decide whether you buy one of the fastest 2.8 lenses or some cheaper but action oriented too alternatives.

The superb DA*300/4 is not a fast lens due to its slow AF motor. There is no comparison, I insist.
04-07-2017, 04:18 AM   #42
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QuoteOriginally posted by redpit Quote
No this is irrelevant too. Otherwise you have to accept that these kind of shots could be taken with a MF lens also. What matters is that Nikon has developed a whole system oriented towards fast action and sport photography. The D300s had great AF and was super fast but with the super fast focusing lenses. It's up to you then to decide whether you buy one of the fastest 2.8 lenses or some cheaper but action oriented too alternatives.

The superb DA*300/4 is not a fast lens due to its slow AF motor. There is no comparison, I insist.
Don't tell this to me. I very much now that Pentax has no alternative to Canon/Nikon in terms of action cameras and lenses. The image from above was posted for Normhead who said he wants to see something that can't be done with Pentax cameras, that's all.

I would expect that a Pentax 150-450mm be as fast as a Nikon D300mm f4 +TC1.4x. If it's not, then this is problem nr. 2 for Pentax users intnetrested in wildlife.

---------- Post added 04-07-17 at 12:14 PM ----------

QuoteOriginally posted by Kunzite Quote
I wonder how many would buy a new Pentax APS-C flagship with much-improved AF, if it would cost 2000 euro.
Don't ask me. Create a poll.

QuoteOriginally posted by Kunzite Quote
I wonder how many would buy a Pentax lens with a 5-digit price... in euro.
Don't ask me. Create a poll.

QuoteOriginally posted by Kunzite Quote
I wonder how many here would shoot kingfishers as well as Mircea Bezergheanu. I know I can't, regardless of which camera I'd be using.
Well, according to him, he can't do that with a D7100 or D810. But he has choices. And that's why he can shoot 7 consecutive frames with the Kignsfisher in flight.

Last edited by Dan Rentea; 04-07-2017 at 05:40 AM.
04-07-2017, 05:17 AM   #43
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You clearly haven't seen what folks like Kengoh have posted using Pentax gear.

The angle that bird is flying a first frame focus lock with AFs and a burst will produce images like that. If that's the best you've to you just proved my point.

Ou guys are so funny, folks come up with some aspect of Pentax af that's better than the competition and you strt with all the reasons why it doesn't count, like little kids on the playground.

The fact that the reasons for doing the test that way a ref ugly explained, yet you toss the results like they were yesterday's trash. As soon as you slow down the guys chanting the mantra, like kids on the playground, they say "well my daddy's smarter" nd start the chant again.

But I have to ask, if all these other companies have such vastly superior AF, why do they do so poorly on this particular test, which measures the AF speed of the camera, taking the speed of the lens out of the equation. WHcih I might add is a perfectly valid way of com pain AF in the bodies independent of lens speed., nd adequately explained on imaging resource. The way they tested the cameras wasn't a mistake. It's a perfectly valid way of testing one aspect of AF performance.

SO then everyone posts with "it doesn't make any difference because Pentax doesn't make any fast focusing lenses." Well now, that's a fine observation. No one has an argument. We are discussing cameras. Now if you want to say Canon and others make the fastest focussing lenses no one is likely to argue with that.

However, Pnetax just as to make one fast focusing lens, and that argument is gone as well. I'm kind of laughing because this fits with my experience.. A have a Tamron SP AF 300 2,8 that is very fast focussing. It would be really interesting to find a Canon or Nikon user with the same lens and run a focus speed test. ANd that's the problem with folks saying in a general kind of way, Pentax has slow AF.

Last edited by normhead; 04-07-2017 at 05:37 AM.
04-07-2017, 05:23 AM   #44
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QuoteOriginally posted by normhead Quote
You clearly haven't seen what folks like Kengoh have posted using Pentax gear.

The angle that bird is flying a first frame focus lock with AFs and a burst will produce images like that. If that's the best you've to you just proved my point.
Let's see those images first. Have you shot a kingfisher and see how erratic they fly? You need at least 1/2500s to freeze him... It's clear to me that your stubbornness is making you so anxious to reply to anything related to Pentax af-c, but don't confuse normal cameras to top action cameras. If everyone would think like you, af-c would not even existed...
04-07-2017, 05:36 AM   #45
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QuoteOriginally posted by normhead Quote
The angle that bird is flying a first frame focus lock with AFs and a burst will produce images like that.
No, it wouldn't. The branch visible in the 1st and 3rd frame is blurrier in the 3rd, but the kingfisher looks to be about the same sharpness. Either the camera is adjusting focus or the photographer is on a big rail and is sliding backwards to match the kingfisher.

QuoteOriginally posted by Kunzite Quote
I wonder how many would buy a new Pentax APS-C flagship with much-improved AF, if it would cost 2000 euro.
I wonder how many would buy a Pentax lens with a 5-digit price... in euro.
I wonder how many here would shoot kingfishers as well as Mircea Bezergheanu. I know I can't, regardless of which camera I'd be using.
No to all three for me!

I'm generally happy with the AF of my Pentax, but I'd be lying if I said I wouldn't like to see that 3-d tracking stuff make an appearance. It looks half decent on the mid-range Nikon bodies, and looks like it would help with my main issues tracking moving targets. I'm not sure how much I'd be willing to pay for it though. We need a good supply of people willing to shell out for that high end, ultra-performance stuff in Pentax land so they can justify developing this sort of thing to trickle down into the more affordable bodies

edit- I googled "Mircea Bezergheanu" to see more of his work - totally worth some time! There are a few awesome photos of him in action handholding a giant lens or in a field with a giant camera and speedos. Plus his work is pretty great too!

Last edited by BrianR; 04-07-2017 at 05:41 AM.
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