Intermittent problem w/AF on K10D

dales · 10-27-2008, 06:31 PM

I have had my K10D for about 1-1/2 yrs now. Once in a great while during that time while shooting in the AF mode the camera would not fire. This had nothing to do w/focus searching. I would switch to manual mode & the problem would go away. After a few shots I would switch back to AF mode & the camera would work fine. I took it to one of the Pentax repair locations & they could not get it to repair the problem. This is no major problem however it is annoying at times. Probable no solution here but wanted to ask if others had experienced the same problem. TIA for the help.

MoiVous · 10-27-2008, 07:06 PM

Originally posted by dales

I have had my K10D for about 1-1/2 yrs now. Once in a great while during that time while shooting in the AF mode the camera would not fire. This had nothing to do w/focus searching. I would switch to manual mode & the problem would go away. After a few shots I would switch back to AF mode & the camera would work fine. I took it to one of the Pentax repair locations & they could not get it to repair the problem. This is no major problem however it is annoying at times. Probable no solution here but wanted to ask if others had experienced the same problem. TIA for the help.

I've noticed that my K200D (effectively a K10D with a few bits missing) doesn't always hunt, but if its not in focus (the little diamond symbol in the viewfinder) it won't shoot.

The K200D user manual states (p105): The shutter cannot be released until the subject is in focus in AF.S (Single mode).

I think your problem may be related to that in some way. The AF relies on transmission of light down into a sensor at the base of the camera through the mirror. If thats affected it could theoretically play up (eg mirror has some dust on it, dust on the AF sensor etc). If you are shooting in fairly low contrast situations things like this might come into play.

Marc Sabatella · 10-28-2008, 01:35 PM

Originally posted by dales

I have had my K10D for about 1-1/2 yrs now. Once in a great while during that time while shooting in the AF mode the camera would not fire. This had nothing to do w/focus searching. I would switch to manual mode & the problem would go away.

I'm not sure if you think the fact that the problem goes away when switching to MF proves it is not related to focus searching, but it doesn't. What convinces you the problem is something other than inability for the camera to achieve focus lock? Are you seeing the hexagon displayed in the status bar indicating that focus lock *has* been achieved, but it still won't shoot?

Also, note the camera will not shoot when flash is enabled but not fully recharged (unless you've selected the option to do so), and it also cannot shoot when the buffer is full. Either of these problems would go away after a few seconds (the flash finishes charging, or the buffer clears), so it might *seem* that it was switching to MF and back that fixed it.

10-27-2008, 06:31 PM	#1
dales Inactive Account Join Date: Sep 2007 Location: Vancouver, Wash. Posts: 26	Intermittent problem w/AF on K10D I have had my K10D for about 1-1/2 yrs now. Once in a great while during that time while shooting in the AF mode the camera would not fire. This had nothing to do w/focus searching. I would switch to manual mode & the problem would go away. After a few shots I would switch back to AF mode & the camera would work fine. I took it to one of the Pentax repair locations & they could not get it to repair the problem. This is no major problem however it is annoying at times. Probable no solution here but wanted to ask if others had experienced the same problem. TIA for the help.

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10-27-2008, 07:06 PM	#2
MoiVous Veteran Member Join Date: Sep 2008 Location: Adelaide, South Australia Photos: Gallery Posts: 677	Originally posted by dales I have had my K10D for about 1-1/2 yrs now. Once in a great while during that time while shooting in the AF mode the camera would not fire. This had nothing to do w/focus searching. I would switch to manual mode & the problem would go away. After a few shots I would switch back to AF mode & the camera would work fine. I took it to one of the Pentax repair locations & they could not get it to repair the problem. This is no major problem however it is annoying at times. Probable no solution here but wanted to ask if others had experienced the same problem. TIA for the help. I've noticed that my K200D (effectively a K10D with a few bits missing) doesn't always hunt, but if its not in focus (the little diamond symbol in the viewfinder) it won't shoot. The K200D user manual states (p105): The shutter cannot be released until the subject is in focus in AF.S (Single mode). I think your problem may be related to that in some way. The AF relies on transmission of light down into a sensor at the base of the camera through the mirror. If thats affected it could theoretically play up (eg mirror has some dust on it, dust on the AF sensor etc). If you are shooting in fairly low contrast situations things like this might come into play.

10-28-2008, 01:35 PM	#3
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Originally posted by dales I have had my K10D for about 1-1/2 yrs now. Once in a great while during that time while shooting in the AF mode the camera would not fire. This had nothing to do w/focus searching. I would switch to manual mode & the problem would go away. I'm not sure if you think the fact that the problem goes away when switching to MF proves it is not related to focus searching, but it doesn't. What convinces you the problem is something other than inability for the camera to achieve focus lock? Are you seeing the hexagon displayed in the status bar indicating that focus lock has been achieved, but it still won't shoot? Also, note the camera will not shoot when flash is enabled but not fully recharged (unless you've selected the option to do so), and it also cannot shoot when the buffer is full. Either of these problems would go away after a few seconds (the flash finishes charging, or the buffer clears), so it might seem that it was switching to MF and back that fixed it.