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04-12-2010, 02:35 PM   #1
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K10D deteriorating focus - is it possible?

Some time ago I read about K10D's "changing" focus... is it possible?

To explain, when I got my FA43 in January, I had to set AF adjustment in debug mode to +190. Few weeks later I moved it to +200, around mid early/mid march it went to +220 and today (12/04) I had to set it to +240 to achieve perfect focus on f1.9. Is this possible or am I going crazy?

The camera has never been dropped, or treated badly. It's just about 18 months old with around 15,000 shutter count by now.

Any ideas???

BR
Peter

04-12-2010, 02:40 PM   #2
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It might just be getting old, the AF motor has a bunch of parts that constantly are working, and I suppose that eventually they will just wear out. It seems like it takes a lot longer usually on any other camera but yours might have some kind of defect. You've never had any kind of problems with focus before now?
04-12-2010, 02:43 PM   #3
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Yea, I agree with jct on this one. As the camera ages finely tuned parts began to wear down and the camera becomes out of spec. I am guessing your going to have to send it to Pentax for repairs.
04-12-2010, 02:43 PM   #4
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Somewhere I read there was a potential issue about the fact that the mirror had a single side rest, and that over time this cause the mirror (and its holding mechanism) to become distorted (tipped) causing loss of focus over time

search the forums, it was recientl;y

04-12-2010, 03:16 PM   #5
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I read similar stories in other forums too in the past. 2 possible causes are 1) the mirror is moving out of alignment slowly (probably the rest arm), 2) the 3 screws holding the AF sensor underneath the mirror box are spring loaded and unscrewing themselves slowly due to insufficient threadlock. Perosnally, I believe #2 is more likely to happen to Pentax DSLRs. The AF motor module itself either works or not, it has nothing to do with AF accuracy.
04-12-2010, 04:03 PM   #6
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This issue was posted earlier by frank. Basically the mirror on the K10D (and K20D) rests on one support pin in the mirror box. As the mirror flips up and down, the mirror will over time start to be off alignment as it comes to rest on one side. The AF sensor located at the bottom of the mirror box is fed light via the mirror, so any mirror misalignment will have an effect on AF accuracy. This issue was came to light quite awhile back. Those with high shutter count, and most K10Ds would fit the bill right now will likely encounter this issue over time. Cameras with this issue will find the AF accuracy to get progressively worse and while the AF module can be manually adjusted if sent for repair, this issue will persist so long as the mirror shifts ever so slightly. Only solution is to replace the mirror box assembly. Focus issues have been the bane for the K10D in the past and this issue will rear it's head again here.

BTW lots of 35mm SLR cameras in the past also had their mirrors resting on a single pin but with film cameras, they don't usually have such a high shutter count compared to their digital counterparts and the thickness of the film emulsion would probably mask some of the focus inaccuracies at the film plane. FYI the K-7's mirror rests on 2 supports, which probably will obviate this issue in the near future.
04-12-2010, 07:43 PM   #7
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Unfortunately, it does seem to happen over time. My K10 gradually began to back focus. I guess the fortunate thing is that it seems to be a global issue, so using the debug mode on the camera seems to fix it over all. I guess you could send in it to Pentax, although in my experience, the cost of these repairs often is more than the camera is worth.
04-12-2010, 11:56 PM   #8
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Thanks for all the replies.
Lowell, I did try to search the forum but didn't come up with the thread I remember...
But the issue I remember was revolving around the one side supported mirror.

anyway, I'll be swapping my main body for my wife's K10D GP, that one is much younger with lower shutter count. So we'll see...

oh well, perhaps it's time to start saving up for K-7

04-13-2010, 07:26 AM   #9
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Axl, your K10D's focus is already detioratiing. May i ask how many shutter count it has right now? Many thanks.
04-13-2010, 01:46 PM   #10
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QuoteOriginally posted by Kenn100D Quote
Axl, your K10D's focus is already detioratiing. May i ask how many shutter count it has right now? Many thanks.
As I said, around 15,000 by now. Maybe bit more, because the pictures' numbering is at ~4500 sencond time now. Considering the manual WB, sensor cleaning procedures etc... maybe aroung 16000. I'll check tomorrow and we'll know for sure!
I did expect the camera to start failing but not after 15k pics only!
04-13-2010, 01:49 PM   #11
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QuoteOriginally posted by axl Quote
Thanks for all the replies.
Lowell, I did try to search the forum but didn't come up with the thread I remember...
But the issue I remember was revolving around the one side supported mirror.

anyway, I'll be swapping my main body for my wife's K10D GP, that one is much younger with lower shutter count. So we'll see...

oh well, perhaps it's time to start saving up for K-7
that is my recollection also.

Note, and I do not believe this is related, but when I had my K10D shutter fail, pentax also replaced the mount and mirror assembly. Makes you wonder.
04-13-2010, 11:57 PM   #12
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QuoteOriginally posted by Lowell Goudge Quote
that is my recollection also.

Note, and I do not believe this is related, but when I had my K10D shutter fail, pentax also replaced the mount and mirror assembly. Makes you wonder.
It does indeed!

it's such a shame, because I love the camera. I really like the ISO100-200 output of the Sony CCD more than that of the Samsung 14mpx CMOS.
And other than this annoying focusing the camera is in great shape.

I may have to ask around if it would be worth having it serviced...
04-14-2010, 01:01 AM   #13
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QuoteOriginally posted by creampuff Quote
This issue was posted earlier by frank. Basically the mirror on the K10D (and K20D) rests on one support pin in the mirror box. As the mirror flips up and down, the mirror will over time start to be off alignment as it comes to rest on one side. The AF sensor located at the bottom of the mirror box is fed light via the mirror, so any mirror misalignment will have an effect on AF accuracy. This issue was came to light quite awhile back. Those with high shutter count, and most K10Ds would fit the bill right now will likely encounter this issue over time. Cameras with this issue will find the AF accuracy to get progressively worse and while the AF module can be manually adjusted if sent for repair, this issue will persist so long as the mirror shifts ever so slightly. Only solution is to replace the mirror box assembly. Focus issues have been the bane for the K10D in the past and this issue will rear it's head again here.

BTW lots of 35mm SLR cameras in the past also had their mirrors resting on a single pin but with film cameras, they don't usually have such a high shutter count compared to their digital counterparts and the thickness of the film emulsion would probably mask some of the focus inaccuracies at the film plane. FYI the K-7's mirror rests on 2 supports, which probably will obviate this issue in the near future.

Yes, I posted this during my version of K7 review last year:

https://www.pentaxforums.com/forums/pentax-dslr-discussion/62819-experiences-...lots-imgs.html

Pity most of the photos were taken out due to lack of space in my free photobucket account, and I don't have them in hand right now.

Some K10D cameras have AF problem right out of box, some would have this problem along the way (and it gets worse). That's another reason you need to upgrade your K10D/K20D to a K7
04-14-2010, 01:04 AM   #14
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In another thread, Lowell mentioned a cost of $325 (or so; canadian I assume) for the repair that he mentions in post #11.

Your call I think it's going to be a difficult one if that is indeed the cost.
04-14-2010, 04:21 AM   #15
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QuoteOriginally posted by sterretje Quote
In another thread, Lowell mentioned a cost of $325 (or so; canadian I assume) for the repair that he mentions in post #11.

Your call I think it's going to be a difficult one if that is indeed the cost.
hahahaha and that's really LOL

for that price? never!
I'd rather keep testing/readjusting as needed on weekly basis

Damn! I hope they'll bring new 2 dial camera out soon or I'll have to sell some stuff to get the K-7 with sensor I really don't like....

oh well, it's a beautiful life.....
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