[CindyV]

Well I will see what they have to say when I take it back in. But you are absolutely right, I don't have time to play games with this camera. It ought to work just like my old one, or it is time to move on to something else. I am just surprised, given the glowing reviews on this camera. I really didn't want to start shopping all over again and possibly spend even more money. Back to the drawing board.

[VisualDarkness]

I still don't really get the problem you ask about. Can you write a short summary?

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.

Is your problem that you do not get focus confirmation or do you get confirmation and get unsharp pictures? Your pic is @ISO25600, that will make a soft image. Also the 18-270 is not a very sharp lens.
Have you tested Live View for focusing as well? Or is it in Live View you have the problem? If so then it is the lens. I have a couple that does not work well with live view but perfect with normal AF.

[CindyV]

I get the blinking light which tells me that it cannot find a focus point, but why does it work sometimes and not other times, even though I am shooting the same scene and not changed the settings?

[VisualDarkness]

It can be the lens too. That lens is really dark at the long end and not the sharpest one around. Those factors together with low light can make it impossible for the camera to use AF. Also it would not be the first time I heard about trouble focusing at the closest distance with super-zooms. Is it only in close, if so how close?

I get the blinking light which tells me that it cannot find a focus point, but why does it work sometimes and not other times, even though I am shooting the same scene and not changed the settings?

So I guess you are not using the Live View? Ok. The K-3 should not have any problems focusing, in low light it is really good. It is the lens for sure or user error. I was shooting water puddles yesterday. Rain and black clouds and my 18-135 WR lens (f3.5 - f5.6). No problems what so ever with the focus locking on at the right spot. Some lenses may cause problems with focus but It has been my experience that it is in Live View the problems occur and we get back or front focus in the image but it still locks on.

Please be more specific on how you do, in what context and so on in your description when the problem occurs so that we can narrow down the problem.

[CindyV]

Hmmm, it sure seems like this guy is right when it comes to the auto focus. Like I said before, if it does not work the way it is supposed to, all the fancy features in the world are not going to matter.

You Tube

You Tube

Hmmm, it sure seems like this guy is right when it comes to the auto focus. Like I said before, if it does not work the way it is supposed to, all the fancy features in the world are not going to matter.

Pentax K3: Two FAILS of the Pentax K-3 - YouTube

That guy has never held the K-3 so I don't think he has a say in the matter.

Since you are the only one on the forum having this problem I would say it is a user error or that your lens is broken.

We have asked you several questions in the thread to be able to help you. Why don't you answer them so we can?


EDIT: Also if you read the comments made for this video you will understand that the guy is way off. Also the DPReview has not yet released a full review for the K-3 but that is a whole other story.

[VisualDarkness]

Yeah, answer the questions instead of linking to really bad "reviews" on youtube, then people can help you.

[fgaudet]

I was gonna write a whole story about this video but I'll keep it simple.

Canikon = faster AF, better at tracking
Pentax = better in low light

All systems are just about as accurate. And for the largest portion of all DSLR users, the difference won't be noticeable in most cases.

More and more, I get the feeling that your lens is not OK, or you have the wrong lens for you needs or your technique is wrong. On your first picture, even if it's hard to tell what or where the subject is, I'm confident that you were too close to focus (<49cm) *Lens limitation. On the second picture at f/11, 180mm (~f/5.6 metering), ISO 25600 and 1/800s shutter, it was more than likely too dark to focus, again a limitation of the lens

[CindyV]

Ya I cannot figure out that high iso either. It was set for mid range auto. But neither of those photos were taken at close range. Both were taken in adequate light. The sun was shining.

Ok, if you do not want to answer the questions asked in the thread your on your own as far as I am concerned. I think a read of the manual would be a good place to start.

[CindyV]

I never use live view. I was shooting in a greenhouse today in very bright light. Like I said before, sometimes it works and sometimes it doesnt. I can try to take a shot and it will lock up. But I can lift my finger off the button and
Immediately hit it again and this time it fires. Nothing has changed with my shooting in that split second.

[awaldram]

Read you issues and it seems as designed to me.
Your old camera sounds like it was faulty.

Let break it down into a few points

There is no such thing as AF1 or AF2 the camera has AF-s , AF-c and AF-a

these do the following

AF-s = single shot AF it will focus and lock, if locked the shutter will fire if you move(sway) then camera will be misfocsused and not fire.

I assume you in this mode shooting at macro distances - if so then because of the high AF resoluition any movement (a fraction of a mm) will notify the camera it is no longer in focus and not fire. It will not attempt to re-focus

@270mm with the lens focused at the min distance your DoF is 0.03mm!! (irrelevant of aperture as camera focuses open aperture)

Depth of field @270mm
Near limit 50 cm
Far limit 50 cm
Total 0.03 cm

You move the camera 0.015mm (from the center) either way and the camer will not release the shutter.!

AF-c = Continuous focus the camera will attempt to keep the target in focus but will allow the shutter to fire even if the camera is not focused in macro shooting this will be constantly out of focsued shots

AF-a = auto the camera will attempt to decied what your doing and swithc AF mode accordingly , in the case of macro (handheld) the camera will believe it is tracking a moving subject switch to af-c and you will get constant oof images.

On other thought if your inside the 18-270 Min distance(20 inches) the camera will never lock and never allow shutter to fire in AF-s



Solution

You need to clean up your technique , AF Macro cannot be shot hand held get a tripod and a 4 way macro rail, rememeber at macro distance only a few mm and your out the DoF, once out the DoF the camera will not fire in AF-s (to stop you taking oof shots)

I assume your 'old' camera had a poor resolution AF sensor so waas unable to tell you had moved OOF and alowed you to take nominally focused shots, The K3 is a different class of camera and will not allow wrong decisions to ruin the image blaming the camera for this is another case of bad workman and his tools.

You will find many on the internet who will happily agree with any off the wall 'issue' and if you push it many wil step forward with the 'same here' this is nothing todo with reality but is human nature we are very suseptable to sugestion.
The fool in that Utube video has as been said never held a K3 has no knowledge of the camera but sees fit to produce that bilge the guys an idiot and you should be very carefull what you 'believe' from unkown web experts.

In my experience 'web experts' are genereally complete tools and know very little but shout loudly how good they are.

[fgaudet]

A few things awaldram,

There is no such thing as AF1 or AF2 the camera has AF-s , AF-c and AF-a

AF-1 and AF-2 are the mode selections for the shutter half-press and the AF button on the back, check your menu

AF-s = single shot AF it will focus and lock, if locked the shutter will fire if you move(sway) then camera will be misfocsused and not fire.

Try it with your camera, every camera I have available at the moment, once the focus is locked, you can move as much as you want and the camera will still fire.

You move the camera 0.015mm (from the center) either way and the camer will not release the shutter.!

If it would behave like this, no camera would ever release its shutter. No photos from a moving car, boat or train. No photos while walking... And no panning shots.