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How is the AF of the K3?

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awaldram said:
awaldram said:
awaldram said:
awaldram said:
I have only tested this about the house - single centre spot, holding my finger half-down and panning around. (DA* 60-250mm f/4 and DA* 300mm f/4). It quickly (but not instantly, of course) focused on what was at the centre. I suspect it is lens-limited, and this is hardly a realistic test.

I did notice one thing that was bit disconcerting with both of these lenses. Occasionally it would fail to focus on something, for example featureless curtains or wall. (OK). The focus indicator hexagram in the viewfinder would blink. (As it should). But continuing the pan to something it should then focus on didn't cause the camera to start trying again. It would then be pointing at something with adequate light and detail for focusing, but the focus indicator would continue flashing and the image would remain blurred.

Only lifting my finger on the shutter button then re-applying it would start it focusing again. I haven't tested my K-5IIs yet to see if that works the same way. Nor do I know whether there is a setting which would improve this.
Click to expand...
Hi Barry,

The K-5, K-5 II, and K-5 IIs works the same way. Lifting of the finger from the button seems to be the normal way to start the process over again. It seems to me to have something to do with time. If you don't get focus lock within a certian time then you have to start the process over again. It's like when you use the DA*300/4 with a 1.4X teleconverter. If you are near focus to begin with then it will focus and lock on. However, if you are way out of focus to begin with then it won't lock on and you have to lift and press again to get the process started again. Sometimes as many as four times before it will lock on.
Click to expand...
Thanks. I would have hoped that this is something that would cured in the K-3. After all, there is much control over AF-C, including some control over timing of loss of focus during tracking. I'll be experimenting! I still don't properly understand all these AF options.
Click to expand...
Are you sure your in af-c?

both af-a and af-s will time out af-c will continue focus but only beep on 1st frame capture, This is normal you really wouldn’t want beep,beep every time lock was reacquired.

The led tell tales will blink to show new acquired target.

Checking my k3 does as I described above.
Click to expand...
Yes it was AF-C.

I was going by the indicator in the viewfinder, (and the sound it makes when focusing), not the beep.

I've just reproduced the effect with AF-C (double-checked!) and my DA* 300mm f/4. It happened in relatively dim conditions indoors. I ended up holding the shutter release half way down, and the focus indicator in the viewfinder flashing, wherever I pointed the camera. Even when I pointed to things that it had successfully focused on seconds before. It is silent - not even attempting to focus.

Once it has lost the ability to focus, and the indicator starts to flash, it appears (sometimes? always?) not to attempt to get a lock when it is re-pointed at something easy to focus on. (Until I release the shutter button and press again).
 
Barry,

As Ron said, this sounds normal behaviour to me.
 
Bill Robb said:
Zenten4 said:
Seriously, how is the AFC of the K3? I am getting a little concerned as everyone seems to avoid answering this.
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This isn't avoidance, this is a camera that has only been in a few people's hands for less than a couple of days. For the record, I have a life outside of photography and I DO NOT test cameras. I get a new camera and when I get time I go out and take pictures. Mostly I shoot static subjects, so I don't use AFC.

You can call this avoidance if you like, though I really resent the implication you've directed at me, but I'm not prepared to waste my life doing a bunch of meaningless tests to see what a camera will do when I will likely never use the capability anyway.

The best answer I can give you, based on very limited experience just from running the camera quickly through it's modes to ensure everything functions, is that it is faster than the K5, more accurate than the K5, and the exposure tracking seems to work.

You will have to wait until people who are not primarily portrait shooters get their hands on the camera and see if you can coax their impressions out of them.
Click to expand...
Can you tell me how the AF works on the K-3 Bill? Thanks. Tom
 
mmm maybe I never let it time out.

I'll retest, da* 300 it is :)
 
awaldram said:
Kevin Coppalotti said:
and how is it with things that move, - planes, trains, birds, bikes and sports? can it lock on and stay locked on to the target? It is touted as a canon killer after all.
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Magnesium alloy Vs plastic ..... I guarantee it's a Canon & Nikon killer :)

DSSI_0047388sml.jpg


Of cause tell a Canon user his cameras has smoking AF and it all goes horribly wrong :)

xlarge_5dashtray.jpg

awaldram said:
--

Kevin Coppalotti
http://maxhr.zenfolio.com/
Click to expand...
--
My PPG
http://www.pentaxphotogallery.com/artists/andrewwaldram
My Photo Stream
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http://1x.com/artist/awaldram/wall
Click to expand...

Where have you hidden this part of the D200?



e1b7da2a7a854db9befc7b2e1875ca16.jpg
 
awaldram said:
mmm maybe I never let it time out.

I'll retest, da* 300 it is :)
Click to expand...
Nope I'm right :)

In AF-c the camera will always attempt to achieve focus irrelevant of AF time out.

The reason you don't see this with the 300 is due to the tracking algorithm that makes small corrections in the direction of mis-focus .

Flicking a 300mm lens between two different distance target creates a phase variance to large to see which way to turn so it doesn't move.

You can prove this two ways

1 use a short focal length lens (16-50 etc)

2 use the 300 but on closer distance targets so the image isn't 100% blurred.

In eother situation AF will continue even if first frame hasn't been established yet.
 
brandrx said:
Barry Pearson said:
Zenten4 said:
Seriously, how is the AFC of the K3? I am getting a little concerned as everyone seems to avoid answering this.
Click to expand...
I have only tested this about the house - single centre spot, holding my finger half-down and panning around. (DA* 60-250mm f/4 and DA* 300mm f/4). It quickly (but not instantly, of course) focused on what was at the centre. I suspect it is lens-limited, and this is hardly a realistic test.

I did notice one thing that was bit disconcerting with both of these lenses. Occasionally it would fail to focus on something, for example featureless curtains or wall. (OK). The focus indicator hexagram in the viewfinder would blink. (As it should). But continuing the pan to something it should then focus on didn't cause the camera to start trying again. It would then be pointing at something with adequate light and detail for focusing, but the focus indicator would continue flashing and the image would remain blurred.

Only lifting my finger on the shutter button then re-applying it would start it focusing again. I haven't tested my K-5IIs yet to see if that works the same way. Nor do I know whether there is a setting which would improve this.
Click to expand...
Hi Barry,

The K-5, K-5 II, and K-5 IIs works the same way. Lifting of the finger from the button seems to be the normal way to start the process over again. It seems to me to have something to do with time. If you don't get focus lock within a certian time then you have to start the process over again. It's like when you use the DA*300/4 with a 1.4X teleconverter. If you are near focus to begin with then it will focus and lock on. However, if you are way out of focus to begin with then it won't lock on and you have to lift and press again to get the process started again. Sometimes as many as four times before it will lock on.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
Click to expand...
I believe it is called a bug and not a feature. Olympus DSLRs had the same issue. don't know why Olympus and Pentax can't overcome this while Canon and Nikon has. BTW, I have all four brands of DSLRs.
 
Last edited:
Zenten4 said:
Seriously, how is the AFC of the K3? I am getting a little concerned as everyone seems to avoid answering this.
Click to expand...
Should point out that the only folks who can really answer this are either 1) K-5x users who really used af-c/tracking before, and/or 2) folks who have used tracking from different manufacturers (Canon/Nikon mostly.)

If someone has never really used tracking before, they have no point of reference for comparison and can't really answer it definitively.

My guess is that's it's going to be faster/better than the K-5 due to the newer ASICs and more cross points, maybe as good as the 70D/D7000, but probably not up to the 7D or D300.

.

--
Here are a few of my favorite things...
---> http://www.flickr.com/photos/95095968@N00/sets/72157626171532197/
 
Last edited:
awaldram said:
awaldram said:
mmm maybe I never let it time out.

I'll retest, da* 300 it is :)
Click to expand...
Nope I'm right :)

In AF-c the camera will always attempt to achieve focus irrelevant of AF time out.

The reason you don't see this with the 300 is due to the tracking algorithm that makes small corrections in the direction of mis-focus .

Flicking a 300mm lens between two different distance target creates a phase variance to large to see which way to turn so it doesn't move.

You can prove this two ways

1 use a short focal length lens (16-50 etc)

2 use the 300 but on closer distance targets so the image isn't 100% blurred.

In eother situation AF will continue even if first frame hasn't been established yet.
Click to expand...
Awaldram,

Hmmm...I was certian that some of my earlier Pentax DSLR would not work like that. I must have been wrong.

I just now tested my K-5 II the following way: AF-C center point, in a darkened room where I could not obtain focus lock, I half-pressed the shutter button and held it half-pressed. The focus racked end to end and did not lock. While continuing to hold the shutter half-pressed for at least 15 to 30 seconds, While continuing to hold the shutter button half-pressed, I then opened the door to the outside daylight and the camera focused on a subject and locked focus. I did that test using both an F*300/4.5 lens and a DA*60-250/4 lens at 250mm.

Ron
 
moving_comfort said:
Zenten4 said:
Seriously, how is the AFC of the K3? I am getting a little concerned as everyone seems to avoid answering this.
Click to expand...
Should point out that the only folks who can really answer this are either 1) K-5x users who really used af-c/tracking before, and/or 2) folks who have used tracking from different manufacturers (Canon/Nikon mostly.)

If someone has never really used tracking before, they have no point of reference for comparison and can't really answer it definitively.
Click to expand...
I've used my K-5IIs a lot with AF-C at 7fps, for airshows and motor sports, etc.

But the UK airshow season has finished, and I haven't been to any motor sports since my K-3 arrived. So I haven't been able to do equivalent tests.

I'm pretty sure it will be better. But I don't yet know how much.
 
moving_comfort said:
Zenten4 said:
Seriously, how is the AFC of the K3? I am getting a little concerned as everyone seems to avoid answering this.
Click to expand...
Should point out that the only folks who can really answer this are either 1) K-5x users who really used af-c/tracking before, and/or 2) folks who have used tracking from different manufacturers (Canon/Nikon mostly.)

If someone has never really used tracking before, they have no point of reference for comparison and can't really answer it definitively.

My guess is that's it's going to be faster/better than the K-5 due to the newer ASICs and more cross points, maybe as good as the 70D/D7000, but probably not up to the 7D or D300.

.
Click to expand...
 
That's funny as hell. Where on earth did you find those pics? Can I pass those along with your permission?

Thanks
 
This is the first time in the thread that you've asked abut AFC. Previously the thread asked about AF in general. They weren't avoiding your question. You didn't ask it.

Paul
 
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[No message]
 
sirharold said:
That's funny as hell. Where on earth did you find those pics? Can I pass those along with your permission?

Thanks
Click to expand...
There linked from free commons licenced sites so not my property.

Just my warped mind thought of conkers so searched for smashed Nikon / Canon and this is what turned up was to funny to ignore. :)

--
My PPG
http://www.pentaxphotogallery.com/artists/andrewwaldram
My Photo Stream
http://www.flickr.com/photos/awaldram/
1x.com
http://1x.com/artist/awaldram/wall
 
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