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04-05-2014, 05:49 PM   #1
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Pentax K-3 autofocus problems

I just bought a K-3 and I am beginning to think it was a huge mistake. On my old camera, when I would press the shutter button halfway it would focus and then if I held it, it would stay focused until I depressed the button all the way and then it would snap the photo. Not so with this camera. When I set it to AF.S mode it will either snap the photo immediately or if I press the button all the way it will not take the shot at all. Because I do a lot of macro, I need it to focus on one spot and then when I move the camera slightly I do not want it to refocus as it does in AF.C mode. In AF.A it responds the same way as in AF.S mode. Is my only option to return the camera?

04-05-2014, 07:06 PM   #2
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Focus with half press, hold AE-L button and the focus (and exposure) will remain locked. But for macro photography, shouldn't you be focussing manually? You could also use one of the many AF points on the K-3 to compose your shot correctly right off the bat and use the proper AF point.

But regardless, in AF-S mode, once focus is locked and the shutter is kept half press, it shouldn't try to re-focus.

Also, the K-3 in AF-S mode will not fire if it hasn't locked focus. No biiiip, no click.

Note that, if your camera was new and you haven't fiddled with the menu settings, the shutter half press should focus BUT if it is a used camera, the previous owner may have disabled the shutter button focus (many people do this). Even if it's new, take a look in the menu under button customization to see what the shutter half press is configured to do.

But if your button is configured to focus on half press and your camera does not focus, it may be broken. Most Pentaxes shutter button gives a good feedback when half pressed.
04-05-2014, 07:24 PM   #3
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It could be a flaky shutter button. That is not very common but is possible. Normally the shutter button half presses quite well and you should have no problems. Does it work properly when you are taking regular pictures, not macro?

AF.S should function as you want. Half press then hold until you press all the way. AF.A lets the camera choose between AF.A and AF.C, I don't recommend it, better to know what you want the camera to do. If it is releasing too soon you might be pressing to hard, if it's not releasing at all then you might not have a focus lock.

Check the button customization as noted above. You might also try setting it to back button focus, which separates the focusing function from the shutter release entirely. I set all my cameras that way as soon as they come out of the box.
04-05-2014, 07:29 PM   #4
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Yes, I have the AF set to a single point. I don't use a true macro lens but I have noticed it does this whether I am focusing close or far away. It is a new camera but I will try it with the AF2 setting under button customization and see what happens. . Sometimes it shoots before I am even ready. There may be a problem with it or it isn't the right camera for me. I just find it hard to believe that others somehow shoot in different way than I do, that they wouldn't be bothered by this AF method on the Pentax.

04-05-2014, 07:35 PM   #5
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Cindy, is the shutter set to only release if focus is first confirmed?
04-05-2014, 07:50 PM   #6
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QuoteOriginally posted by CindyV Quote
I just find it hard to believe that others somehow shoot in different way than I do, that they wouldn't be bothered by this AF method on the Pentax.
The Pentax AF and shutter release works exactly like any other brand of camera. It should be doing what you want it to, if it's not then there is a setting wrong or the button is defective. First I've heard of that on the k-3 but the k-x and k-5 both had issues where the shutter release would stick or not work right.

One way of fixing the problem on the older models was to turn off the camera, then press the shutter button firmly all the way down repeatedly, like 20 times. Then try the camera again and see if it works. This camera is weather resistant and has a lot of seals protecting everything, sometimes things just need to wear in to work right, sometimes a bit of grit gets into the area around the button. Not sure if that will fix your issue as so far I've not seen anyone have the problem on the k-3 but it costs nothing to try.

If that does not help I would consider returning it as defective. Assuming you checked the settings under button customization and everything is correct.
04-05-2014, 07:57 PM   #7
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When I set it to AF2 as opposed to AF1 it is supposed to fire only when shutter button is pressed but not halfway. It did not work that way. It fired without focusing at all. I am going to take it back to the store on Monday and if it can't be fixed, I will ask for a refund and start shopping all over again.
04-05-2014, 08:36 PM   #8
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QuoteOriginally posted by CindyV Quote
Sometimes it shoots before I am even ready
Just to be sure, by "half pressing" the button, you should not feel it click, you only need to apply slight pressure on it. If you feel it click, that's full press. The shutter doesn't have two "clicks" like you would find on some older SLR and on some P&S

What you are describing now seems like you are fully depressing the button. I can recreate the exact behaviour here with my K5 and my K-r if I fully depress the shutter in AF-S right away (no half press).

But as jatrax said, some camera may have shutter button issues. My K-r shutter button wouldn't do half presses (after taking 10 000 shots). I had to clean it as dust got into it. But this is not something you would get on a brand new WR camera

04-05-2014, 09:21 PM   #9
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That was something I found interesting, I am getting spots showing up on my pics, just like I have been getting with my old camera that has over 80,000 clicks on it, but with this camera I was noticing a few spots from sensor dust after just 100 shots. It seems like a defect with the camera because I know the difference between half and whole on the shutter button, even though it is more sensitive than my old DSLR.
04-05-2014, 10:28 PM   #10
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Can you upload pics?
04-05-2014, 11:06 PM   #11
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I enlarged it so you could see the spots.
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04-06-2014, 05:18 AM   #12
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This sure looks like crap on a sensor. And unless you live in a permanent dust storm and you voluntarily leave your camera without a lens or cap for extended period of time, this isn't normal on a new camera. Especially with a WR camera coupled with a WR lens. If you lock the mirror up, can you see "what" is on the sensor? Dust/oil/??? If you have a rocket blower, you can try blowing it off.

Just for the fun of it, check your shutter count and see if it roughly matches the number of photos you have taken. Some seller on Amazon have way too easy return policy and you may have ended up with a "returned" camera. Some resellers are also very good at selling their floor model / demo as "new".

Check Shutter Count & Camera Manufacture Date Online - EXIF Reader

QuoteOriginally posted by CindyV Quote
It seems like a defect with the camera because I know the difference between half and whole on the shutter button
And sorry if my previous post sounded rude or patronizing. This is exactly the point I was trying to make. The camera should behave as you want it to but it does look like the shutter button isn't making proper contact when half press. I am assuming the K-3 button is similar if not identical to the K-5 and I can easily keep the button half pressed for minutes while moving the camera.

Pentax in the past had issues with "over-greassing" buttons and wheels (google K-r back wheel problems). Although no one ever reported any such problems in a while, the may have hired a grease gun trigger happy assembly line worker.

Looking closely at the Exif data from you picture, I see your K-3 is still on Firmware 1.00, maybe you could try to update it to the latest firmware (1.03) and see if it helps with your shutter issues (won't help with sensor dust however).

Pentax Firmware Updates - PentaxForums.com Homepage Blog
04-06-2014, 08:04 AM   #13
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Thank you, you have been a big help. Well even though I normally buy on Amazon, and even though I could have saved a little money by buying it from B+H or Adorama, this time I did the right thing and supported my local camera store. I will be taking this problem up them when they open tomorrow. My friends who have bought from them have told me they will do the right thing, so I am hoping that will be the case. I did a lot of research before I chose this camera and I had never owner a Pentax before, so I am hoping this was just a fluke and I will be able to get my hands on one that really works.
04-08-2014, 06:16 PM   #14
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I returned the camera to the store and they were not able to remove the spots on the sensor, so they gave me a new camera body. However, I am still having the same issue with the auto focus. Is it possible that there may be a problem with the lens? I am using an 18-270 Pentax. I used a 28-300 Tamron on my old camera and never had any problems with it. It only releases the shutter about 85-90% of the time. Otherwise it will not fire at all. I can get it to work if I let up my finger and try again. I am not changing my position or camera settings. I am starting to lose patience. I mean I could buy a camera that costs a fraction of the price and not have to deal with this. The photo is one instance of what I was shooting. So there is plenty of contrast.
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04-08-2014, 07:07 PM   #15
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Hey Cindy, glad to hear your store is a good one!

For the focus issue, I only realize you're using an SDM lens, I don't know about the 18-270 but my 50-135 isn't my favorite focus wise. The SDM does lag a bit and doesn't feel as direct as a screw drive one. I haven't read many reports of SDM issues with the 18-270 but maybe it's acting up. And SDM is pretty slow, noticeably slower on some lenses and the few ones I have do like to refocus once in a while.

Would it be possible for you to try your camera with another lens, preferably a screw-driven one? SDM might not be ideal for your shooting style. You can get a Tamron 28-300 on the cheap for Pentax K.

One thing to remember though is the minimum focussing distance of your lens is 49cm (~19"). This might be a problem, the lens will never be able to acquire focus on an object closer than 49cm. It is however the exact same minimum focus distance of the Tamron 28-300.

Just to be sure, when you half press your shutter, you do get a focus confirm Bip and the corresponding focus point lighting up in the VF? Because no Bip will mean that you don't have focus, if you move, it'll try to focus again. And as it was mentionned, no focus, no release in AF-S (or AF-A which no one should use). If you don't get a bip, you may be too close, or in the case of the picture above (maybe), your subject is moving faster than the lens can move or it might be too dark (the 18-270 needs a lot of light to focus, especially at the long end)

QuoteOriginally posted by CindyV Quote
I mean I could buy a camera that costs a fraction of the price and not have to deal with this.
This is true but remember that what you are experiencing is not a typical problem, you've got most of us baffled with the issue. But as it was said before, every DSLR shutter button works the same way, every bridge camera and every P&S I tried too. And it should work as you want it to. Half press, AF focussing, BIP, move while staying half-pressed maintaining focus and then fully depress to release. I tried with all my cameras (K5, K-r, K100D, Q, cheapo Panasonic P&S, the girlfriend T4i and Sony A57) and I cannot get them to act like your K-3

But if you're not happy with what you've got, might as well change. A K-3 is a pretty expensive piece of gear, especially if you don't like it. But try to eliminate possible issues with other things, like your lens before returning one of the best available APSC camera available at the moment...
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