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02-11-2024, 10:32 AM   #1
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My first test of my new K3iii Continous Focus - a disaster

Just a bit of background. I have never used AF:C and have used Pentax dSLRs for 15 years. I always use centre spot and recompose the shot. As such, on a moving animal for example, I spend most of my time ensuring I nail the focus by continously moving the camera left and right as I move the subject's head back into the centre to focus, then quickly move the camera for the best composition. One of the reasons I got the K3iii was that I read about its game-changing focus. As such today I mounted the DA150-450mm and shot a swan at a lake nearby. The swan was swimming slowly and generally just moving around the lake. The light was excellent and I used my normal shutter speed/aperture of 500th and F5.6
The first thing that I thought was brilliant is that not once did the camera suddenly focus on reeds, even though some of the shots I was shooting straight through them. Brilliant stuff.
I am a total newbie on here with the K3iii and also AF:C. The mode I was on was AF:C with the larger matrix area. On getting home I was disappointed to see that most shots were failures. I reckon 12 out of 50 shots had the correct focus. I have flagged these as yellow in LR and the fails as red. On many, the ripples well in front of the subject were in focus, so I assumed it must be a calibration issue, and that the camera was correctly choosing the subject, but then the lens was out of calibration. (On my old K3ii the focus is perfect BTW). However, on looking at the on-screen information display on the camera I noticed that the focussing spot was hardly ever where I would have expected it to be. Have a look at the shot of the cameras LCD screen to see what I mean. It's at the bottom with the swan dead centre! I am not sure what else I could have done. Basically, what am I doing wrong?

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02-11-2024, 10:54 AM - 2 Likes   #2
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Don't use large area for birds. I use ex s spot or select. Use back button and establish the focus in the center first. If you're using shutter release for focus it will want to refocus everytime you press button. Auto area rarely works for birds. If your going to use it you really have to pay attention to where the focus ndicator squares land. Zone works pretty good for bif against a sky or a limited background. They key is establishing center focus on subject first. Watch the focus indicators as you track. If they're moving off subject, release focus and re-establish. What I do anyway.

Last edited by Ski Jumper; 02-11-2024 at 11:24 AM.
02-11-2024, 11:28 AM   #3
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Make sure you have latest firmware installed too.
02-11-2024, 11:38 AM   #4
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QuoteOriginally posted by Ski Jumper Quote
Don't use large area for birds. I use ex s spot or select. Use back button and establish the focus in the center first. If you're using shutter release for focus it will want to refocus everytime you press button. Auto area rarely works for birds. Zone works pretty good for bif against a sky or a limited background. They key is establishing center focus on subject first. Watch the focus dots as you track. If they're moving off subject, release focus and re-establish. What I do anyway.
Indeed, also using Center zone or spot focus for birds & moving animals, any wider zone focus setting will also try to get foreground and background in focus , hence focussing everywhere... , next thing is that you need to keep track of the bird in the center zone...
On a K3-II I also set af focus holding time to medium and use the expanded zone setting (allows focus point to shift to neighbour point of original focus point)....not sure what K-3-3 needs but this kind of subject might need some more settings than af.c alone....

02-11-2024, 11:39 AM   #5
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I have two user modes set up for birds, one mode like ski jumper has written above, I'm agreeing with him that the method work great. I have another set for "flight", it uses the grid like you are showing and works pretty well for birds in flight. It will actually work well on still subjects if you center focus first and remove the thumb from the focus button (back button focus), which is basically spot focus and re-compose, which I did with previous cameras too. That would never work using the shutter button for focus.
02-11-2024, 11:52 AM   #6
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Thanks all. Just to add that I am on the latest firmware. I am going to look into setting user modes. I have never used them before but, with a camera this complex, I will definitely use them now.
02-11-2024, 12:15 PM   #7
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QuoteOriginally posted by mlag Quote
Indeed, also using Center zone or spot focus for birds & moving animals, any wider zone focus setting will also try to get foreground and background in focus , hence focussing everywhere... , next thing is that you need to keep track of the bird in the center zone...
On a K3-II I also set af focus holding time to medium and use the expanded zone setting (allows focus point to shift to neighbour point of original focus point)....not sure what K-3-3 needs but this kind of subject might need some more settings than af.c alone....
I just started using hold recently after reading one of the forum articles by beholder3 on "af hold". I've had it off. Most of my bif are moving parallel or in a swooping 45 deg angle. Sounds like having it off in this scenario can cause more problems than help.

02-11-2024, 12:52 PM - 1 Like   #8
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Check out Kobie here. He’s done some good analysis of the k-3iii focus modes.
02-11-2024, 12:54 PM   #9
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I am pretty sure in your example you have it set to pick your own focus point. So in your example you are trying to focus on that bottom spot. You use the joystick to move your chosen focus point or press the joystick down in the neutral position to recenter the focus point. Spend some time going through the various focus methods. It is quite a complex system with many options.
02-11-2024, 03:29 PM   #10
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Actually, it was the first test of a photographer with his new camera! Still long for a digital that has no more than what I had on my Super A. Fun of a digital camera is that you can set it so that you have indeed a Super A Digital. I once used AF-C and it is not likely that I will ever do that again (it is bit of a setting to let the lens hunt....). I also think that the swan was too far away for "easy" focusing. But I can be wrong because it is very difficult to see for me on all those small pictures.
QuoteOriginally posted by tigershoot Quote
the lens was out of calibration. (On my old K3ii the focus is perfect BTW).
That sounds/reads as impossible, if the calibration on the K-3 Mark II is perfect, there must be something wrong with its sibling, the III. I have a K-3 Mark II, then the KP and since a few months a K-3 Mark III. Lenses that I used on my Samsung GX-10 found their way to the Mark III and not any of those lenses needed calibration or the camera AF adjustment. So try your new camera with pictures taken with AF-S and then look at the results. I believe that your pictures suffered from AF-C rather than a lens out of calibration or a wrong AF adjustment of the camera. As you stated you are a newbie to AF-C. And perhaps a little more experience with it might help. I am one that take pictures of cats and always use AF-S. And yes, I have plenty of shots that are not right. But the cats move or suddenly start to scratch. And sometimes especially with a waterbird swimming towards you, you can profit from catch in focus. Enjoy your new camera and give it time so that it can get used to you .
02-12-2024, 06:21 AM - 1 Like   #11
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QuoteOriginally posted by AfterPentax Mark II Quote
Actually, it was the first test of a photographer with his new camera! Still long for a digital that has no more than what I had on my Super A. Fun of a digital camera is that you can set it so that you have indeed a Super A Digital. I once used AF-C and it is not likely that I will ever do that again (it is bit of a setting to let the lens hunt....). I also think that the swan was too far away for "easy" focusing. But I can be wrong because it is very difficult to see for me on all those small pictures.

That sounds/reads as impossible, if the calibration on the K-3 Mark II is perfect, there must be something wrong with its sibling, the III. I have a K-3 Mark II, then the KP and since a few months a K-3 Mark III. Lenses that I used on my Samsung GX-10 found their way to the Mark III and not any of those lenses needed calibration or the camera AF adjustment. So try your new camera with pictures taken with AF-S and then look at the results. I believe that your pictures suffered from AF-C rather than a lens out of calibration or a wrong AF adjustment of the camera. As you stated you are a newbie to AF-C. And perhaps a little more experience with it might help. I am one that take pictures of cats and always use AF-S. And yes, I have plenty of shots that are not right. But the cats move or suddenly start to scratch. And sometimes especially with a waterbird swimming towards you, you can profit from catch in focus. Enjoy your new camera and give it time so that it can get used to you .
I think the OP would be doing himself a big disservice if he went back to AF-S for moving subjects like birds. The K-3 Mark III has a lot of capabilities that previous Pentax bodies were lacking. My suggestion is what others have mentioned, look in the K-3 Mark III forum here for posts by Kobie and others that discuss AF settings in some detail and really work to set up the camera for the situations he's expecting.

And it's not at all unusual to have to do focus micro-adjust on a lens/body combination that didn't require it on another body. I would definitely set up a controlled situation with a tripod and some kind of focusing target and really dial in the K-3 Mark III and his 150-450. Of course being a Pentax DSLR, it's pretty likely this will end up being a compromise. There's only one micro-adjust setting stored per lens, and it's possible or even probable that you want, say, -1 at 150mm but -4 at 450mm, and he'll just have to choose something in the middle works best.

---------- Post added 02-12-24 at 08:25 AM ----------

QuoteOriginally posted by cuepics Quote
I am pretty sure in your example you have it set to pick your own focus point. So in your example you are trying to focus on that bottom spot. You use the joystick to move your chosen focus point or press the joystick down in the neutral position to recenter the focus point. Spend some time going through the various focus methods. It is quite a complex system with many options.
I shoot mostly soccer, and birds are not soccer players. But, my experience is that the largest autofocus areas end up focusing on something but not necessarily what you want to focus on. I typically use one of the small or medium SEL areas, and use the joystick to initially pick my subject.

And I have found I get much better results with back button focus than having the shutter button pull double duty.
02-12-2024, 09:18 AM   #12
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I like this kind of posts. It's a good test to know if Pentaxians know their cameras or not.
Did anyone mention the obvious, setting AF-C to focus priority vs FPS priority? K3 III manual page 61.
02-12-2024, 11:54 AM   #13
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QuoteOriginally posted by biz-engineer Quote
I like this kind of posts. It's a good test to know if Pentaxians know their cameras or not.
Did anyone mention the obvious, setting AF-C to focus priority vs FPS priority? K3 III manual page 61.
Hopefully in the next few days the weather will be good and I will try again. I was not rapid firing in my test. I will try the narrower focussing area. For old time's sake I will try the K3ii as well.
As for calibration, I have never needed to do it. I believe thought it's perfectly possible for it to be the case that my K3ii/150-450mm combo does not need it, but the same lens attached to the new K3iii might need it. Say for example my DA150-450mm is 2 positive increments out of perfect calibration. My K3ii might also be slightly out, and just for argument's sake it's 2 positive increments out as well. As such they are perfectly suited. Mount it to my new K3iii though, and that body might be negative 2 increments out. It would then seem way off compared the the K3ii. Hope I am making sense, but this is how I understand that one lens might be perfect on one camera, but seem way out of kilter on another.
02-12-2024, 06:05 PM   #14
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QuoteOriginally posted by tigershoot Quote
Hopefully in the next few days the weather will be good and I will try again. I was not rapid firing in my test. I will try the narrower focussing area. For old time's sake I will try the K3ii as well.
As for calibration, I have never needed to do it. I believe thought it's perfectly possible for it to be the case that my K3ii/150-450mm combo does not need it, but the same lens attached to the new K3iii might need it. Say for example my DA150-450mm is 2 positive increments out of perfect calibration. My K3ii might also be slightly out, and just for argument's sake it's 2 positive increments out as well. As such they are perfectly suited. Mount it to my new K3iii though, and that body might be negative 2 increments out. It would then seem way off compared the the K3ii. Hope I am making sense, but this is how I understand that one lens might be perfect on one camera, but seem way out of kilter on another.
2 positive @450? Wow I'm at a -6 or -7 both k3 and k1. I must have a crappy copy.
02-13-2024, 04:35 AM   #15
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QuoteOriginally posted by tigershoot Quote
As for calibration, I have never needed to do it. I believe thought it's perfectly possible for it to be the case that my K3ii/150-450mm combo does not need it, but the same lens attached to the new K3iii might need it. Say for example my DA150-450mm is 2 positive increments out of perfect calibration. My K3ii might also be slightly out, and just for argument's sake it's 2 positive increments out as well. As such they are perfectly suited. Mount it to my new K3iii though, and that body might be negative 2 increments out. It would then seem way off compared the the K3ii. Hope I am making sense, but this is how I understand that one lens might be perfect on one camera, but seem way out of kilter on another.
Calibration has nothing to do with the camera AF focusing on the wrong thing in the frame. I would recommend to leave lens calibration at 0. On the other hand, I'd suggest setting AF-C first frame to focus priority as it is written in K3 III user manual page 61.
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