K3 III: AF-C on static objects

[Tord S Eriksson]

Hello MighthyMike

You're asking an algorithm to track something that isn't moving except that the algorithm is expecting movement so now its confused, it doesn't know what you want in focus because the item you've focused on isn't moving. Computer algorithms are far simpler than our eye-brain communication, you can't expect them to read your mind or to figure out that you don't want it to do what it was programmed to do. Why else would there be at least two AF choices available, one for moving subjects and one for static subjects!

I wrote that my K5, K1 and KP don't do that, so why do you think I can't demand that from an AF-C? And of course my camera knows what I want: I use only one AF point and when I focus, the camera knows that this AF point needs to be brought into focus. This is a very simple application!

For example a good result test of the K3 III AF-C:

AF-C with the first image set to focus priority:

So to test, point the camera at a static object (which is out of focus) and press down completely the shutter release button:

- the K5 almost never focused good on the object, it always released the shutter far too early (the AF motor was still running and after the picture also). The K5 was unusable here and you always had to wait until the AF motor came to a standstill and than you could press down completely the shutter release button.

Ah, the K-5! If it wasn't the AF I would still be a Pentax fan, but even the tiny Nikon 1 V1 outperformed my K-5 in every way when it came to startup time and AF!

- the K3 III is excellent here, the images of my static subject are in this test excellent in focus !

Never tried the K-3, sadly.

AF-On is something I have on all my Nikon cameras (except the Nikon 1 cameras), a blessing, definitely!

 

[William the X-T5 guy]

I'd call that a workaround not a solution. The very point of back-button focus is this:

You never have to do the switch, because the shutter button works the shutter and the back button works the focus and they are decoupled. If it's a static subject, you press the back button and then the shutter. If you release the back button first you can focus and recompose. If the subject moves, or you suddenly choose a new subject that's moving, well you just need to keep the back button pressed.

Good explanation here

https://photographylife.com/back-button-focus

Paul

[clip] The solution is to flick the switch over to AF-S when the subject isn't fleeing. [clip]

Call it what you want, but this is the way the camera works. Either learn to live with it or don't and complain on internet forums.

It's a pretty insignificant First World problem when all one needs to do is flick the switch that is conveniently placed within easy reach, but rather than do that make it into a planet killing asteroid.

 

[Ian Stuart Forsyth]

You're asking an algorithm to track something that isn't moving except that the algorithm is expecting movement so now its confused, it doesn't know what you want in focus because the item you've focused on isn't moving. Computer algorithms are far simpler than our eye-brain communication, you can't expect them to read your mind or to figure out that you don't want it to do what it was programmed to do. Why else would there be at least two AF choices available, one for moving subjects and one for static subjects!

I have never had this problem when using AF-C with other manufactures, matter of fact 99% of the time I use AF-C for about everything I shoot

Well, you have with the K3III. The solution is to flick the switch over to AF-S when the subject isn't fleeing.

One of the problems is that a lot of the time I am photographing subject that are stationary with no movement and in a fraction of a second the subject will move, this becomes even more of a problem when shooting wide open with 300 and 400 mm lens.

Then next problem is that the subject might be stationary while the air currents can cause problems with the subject moving in and out of focus without the subject even moving

At the same time, it's good to note it and perhaps do a customer feedback report. It may be an overlooked bug that is fixable.

 

[Ian Stuart Forsyth]

I'd call that a workaround not a solution. The very point of back-button focus is this:

You never have to do the switch, because the shutter button works the shutter and the back button works the focus and they are decoupled. If it's a static subject, you press the back button and then the shutter. If you release the back button first you can focus and recompose. If the subject moves, or you suddenly choose a new subject that's moving, well you just need to keep the back button pressed.

Good explanation here

https://photographylife.com/back-button-focus

Paul

[clip] The solution is to flick the switch over to AF-S when the subject isn't fleeing. [clip]

Call it what you want, but this is the way the camera works. Either learn to live with it or don't and complain on internet forums.

Great opinion, shut up and don't complain.

The OP is someone how does similar work to me and this is where the K3 III is marketed for

It's a pretty insignificant First World problem when all one needs to do is flick the switch that is conveniently placed within easy reach, but rather than do that make it into a planet killing asteroid.

--
The Camera is only a tool, photography is deciding how to use it.
The hardest part about capturing wildlife is not the photographing portion; it’s getting them to sign a model release

 

[Paul_R_H]

Hi William

Please don't get sniffy. I thought we were here to help one another. I was grateful that you contributed by suggesting switching to AF-S. I should have expressed my gratitude.

But for reasons that I explained, it doesn't really feel like a solution to me, and it wasn't necessary on the previous Pentax bodies.

At no point have any of us here said this is a planet-killing asteroid, or made any observation at all on the magnitude of the problem when compared with other personal difficulties or the wider world's many problems.

We're just pointing out an issue that's new with this camera, and that maybe there's a simple solution that some people in this mutual-help forum might have come across. Then those of us who still have the issue could benefit from that knowledge.

Best

Paul

I'd call that a workaround not a solution. The very point of back-button focus is this:

You never have to do the switch, because the shutter button works the shutter and the back button works the focus and they are decoupled. If it's a static subject, you press the back button and then the shutter. If you release the back button first you can focus and recompose. If the subject moves, or you suddenly choose a new subject that's moving, well you just need to keep the back button pressed.

Good explanation here

https://photographylife.com/back-button-focus

Paul

[clip] The solution is to flick the switch over to AF-S when the subject isn't fleeing. [clip]

Call it what you want, but this is the way the camera works. Either learn to live with it or don't and complain on internet forums.

It's a pretty insignificant First World problem when all one needs to do is flick the switch that is conveniently placed within easy reach, but rather than do that make it into a planet killing asteroid.

 

[William the X-T5 guy]

Hi William

Please don't get sniffy. I thought we were here to help one another. I was grateful that you contributed by suggesting switching to AF-S. I should have expressed my gratitude.

But for reasons that I explained, it doesn't really feel like a solution to me, and it wasn't necessary on the previous Pentax bodies.

At no point have any of us here said this is a planet-killing asteroid, or made any observation at all on the magnitude of the problem when compared with other personal difficulties or the wider world's many problems.

We're just pointing out an issue that's new with this camera, and that maybe there's a simple solution that some people in this mutual-help forum might have come across. Then those of us who still have the issue could benefit from that knowledge.

Best

Paul

Report it as a bug to Pentax since it sounds like a them problem. That's the only way we have of getting a fix. Until then, use the AF switch.

 

[Kobie M-C]

Hello John Venables

Which version of firmware is your camera?

The newest

The AF-c on the K3iii has a lot more options than previous pentax cameras.

More options were added with firmware update 2.00

see https://www.ricoh-imaging.co.jp/english/products/k-3-3/firmup/

See menu still image / 1 AF with Viewfinder

scroll down to Focus Sensitivity in AF.C

I had try that too: it makes no different.

These settings only determine the behavior when the AF-C detects a change in phase position. But with my static objects there is no change in phase position. In my last thread I posted pictures from a bicycle race (i.e. a kind of bicycle test). Even when the riders were so close that at 450mm only the head and upper body was visible in the scene, the AF-C was able to follow very often. In other words: When there is a movement, the algorithm doesn't have the time for such ''games'', but when the object stands still, it falls into them. I do not know why. All I know is that my KP, K5 and K1 just don't do it.

There are five choices

５：Emphasize Trackability
AF Tracking mechanism activated when the subject makes even a slight motion in the direction of depth
４

３：Standard
Conventional AF tracking mechanism, set as default
２

１：Emphasize Stability
AF Tracking mechanism activated when the subject makes a large motion in the direction of depth.

To achieve the result you want you need to choose sensitivity 1.

best regards. KPM2

It could very well be a spec of something or residue on the mirror or the Focus sensor. I had an issue where the AF in AF.C just wasn't behaving right. The bottom of the mirror had some residue on it and I went ahead and cleaned both the mirror and AF sensor under the mirror just in case, and the camera performed like a champ after that.

--
I am not a Pentax insider. I just have a unique way of gaining insight.

 

[LDBOK]

I have the K3 III and don’t have this problem.

 

[Paul_R_H]

Report it as a bug to Pentax since it sounds like a them problem. That's the only way we have of getting a fix. Until then, use the AF switch.

The camera went back to Pentax UK. Came back to me. Still no better. They eventually acknowledged the problem. Couldn't fix it and sent a brand-new one. I hope that counts as reporting. It certainly cost them money. And the new one behaves exactly the same.

Paul

 

[Paul_R_H]

It could very well be a spec of something or residue on the mirror or the Focus sensor. I had an issue where the AF in AF.C just wasn't behaving right. The bottom of the mirror had some residue on it and I went ahead and cleaned both the mirror and AF sensor under the mirror just in case, and the camera performed like a champ after that.

Thanks for your suggestion.

Two years ago and often since I've rigorously cleaned the mirror box and AF sensor. No change in this issue.

Sent it back for Pentax UK for a clean and examination. No change.

Tried different lenses including brand-new copy of 16-85 in the shop. Plus screw-drive 15 and 28. No change.

Got a brand new camera on warranty. No change.

See above for my list of other menu alterations and other attempts to fix it. The issue persists exactly as I and the OP and others have described it.

Paul

 

[Kobie M-C]

It could very well be a spec of something or residue on the mirror or the Focus sensor. I had an issue where the AF in AF.C just wasn't behaving right. The bottom of the mirror had some residue on it and I went ahead and cleaned both the mirror and AF sensor under the mirror just in case, and the camera performed like a champ after that.

Thanks for your suggestion.

Two years ago and often since I've rigorously cleaned the mirror box and AF sensor. No change in this issue.

Sent it back for Pentax UK for a clean and examination. No change.

Tried different lenses including brand-new copy of 16-85 in the shop. Plus screw-drive 15 and 28. No change.

Got a brand new camera on warranty. No change.

See above for my list of other menu alterations and other attempts to fix it. The issue persists exactly as I and the OP and others have described it.

Paul

Interesting. I can use AF.C on static subjects with no issue, I just change the sensitivity to 1 = Emphasise Stability and use AF type 2 or 3 (Not using the AE + AF option).

 

[Tord S Eriksson]

Report it as a bug to Pentax since it sounds like a them problem. That's the only way we have of getting a fix. Until then, use the AF switch.

The camera went back to Pentax UK. Came back to me. Still no better. They eventually acknowledged the problem. Couldn't fix it and sent a brand-new one. I hope that counts as reporting. It certainly cost them money. And the new one behaves exactly the same.

Paul

The tragedy with Pentax is the unfixable problems, I got a K-5 for free when the old one had card reader problems, as evidently, that was unfixable as well. That made me lose faith in Pentax (I still bought a GR, silly me, a costly mistake).

 

[LDBOK]

Report it as a bug to Pentax since it sounds like a them problem. That's the only way we have of getting a fix. Until then, use the AF switch.

The camera went back to Pentax UK. Came back to me. Still no better. They eventually acknowledged the problem. Couldn't fix it and sent a brand-new one. I hope that counts as reporting. It certainly cost them money. And the new one behaves exactly the same.

Paul

What focus area are you using. I use AF-C and SEL 1 for photographing birds, so I can focus on the eye if I’m close enough, or the head if farther away. As long as I can hold the point on the eye it locks focus, and will not change focus unless I wobble or the bird moves.

 

[Paul_R_H]

Report it as a bug to Pentax since it sounds like a them problem. That's the only way we have of getting a fix. Until then, use the AF switch.

The camera went back to Pentax UK. Came back to me. Still no better. They eventually acknowledged the problem. Couldn't fix it and sent a brand-new one. I hope that counts as reporting. It certainly cost them money. And the new one behaves exactly the same.

Paul

What focus area are you using. I use AF-C and SEL 1 for photographing birds, so I can focus on the eye if I’m close enough, or the head if farther away. As long as I can hold the point on the eye it locks focus, and will not change focus unless I wobble or the bird moves.

Yes, that's what I use too. Although trust me I've tried all the others.

Paul

 

[Oiche]

Report it as a bug to Pentax since it sounds like a them problem. That's the only way we have of getting a fix. Until then, use the AF switch.

The camera went back to Pentax UK. Came back to me. Still no better. They eventually acknowledged the problem. Couldn't fix it and sent a brand-new one. I hope that counts as reporting. It certainly cost them money. And the new one behaves exactly the same.

Paul

The tragedy with Pentax is the unfixable problems, I got a K-5 for free when the old one had card reader problems, as evidently, that was unfixable as well. That made me lose faith in Pentax (I still bought a GR, silly me, a costly mistake).

The card reader is probably integrated onto the main board, I know of other cameras where a USB socket was faulty and required a whole new main board!

Pentax UK replaced my K-30 outside guarantee (about 6 months) when rain destroyed it. They said the rear LCD seal was defective.

A long time ago now, maybe 10 years.

--
tordseriksson (at) gmail.....
Owner of a handful of Nikon cameras. And a few lenses. DxO PhotoLab user.
WSSA #456

 

[Tord S Eriksson]

Report it as a bug to Pentax since it sounds like a them problem. That's the only way we have of getting a fix. Until then, use the AF switch.

The camera went back to Pentax UK. Came back to me. Still no better. They eventually acknowledged the problem. Couldn't fix it and sent a brand-new one. I hope that counts as reporting. It certainly cost them money. And the new one behaves exactly the same.

Paul

The tragedy with Pentax is the unfixable problems, I got a K-5 for free when the old one had card reader problems, as evidently, that was unfixable as well. That made me lose faith in Pentax (I still bought a GR, silly me, a costly mistake).

The card reader is probably integrated onto the main board, I know of other cameras where a USB socket was faulty and required a whole new main board!

Could well be so, not a wise design, service-wise!

Pentax UK replaced my K-30 outside guarantee (about 6 months) when rain destroyed it. They said the rear LCD seal was defective.

A long time ago now, maybe 10 years.

That's roughly when I gave up on Pentax, still got the K-x and the wife has her K-30, but neither is used any longer! And the GR gets some use, but not much!