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Author Topic: Question regarding focusing  (Read 1136 times)

wsmith96

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Question regarding focusing
« on: July 22, 2013, 10:07:34 PM »
Over the past six months I've been noticing that my pictures are getting fuzzier than what I've experienced in the past.  The problem is probably me, but the only lens that seems to be consistently sharp is my 60mm macro.  Do auto-focusing systems get out of calibration?  I've had me camera since 2009 when it was first released and have not done any adjustments to it.

thanks in advance,

Wes
What I do today is important because I am exchanging a day of my life for it.

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Question regarding focusing
« on: July 22, 2013, 10:07:34 PM »

BozillaNZ

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Re: Question regarding focusing
« Reply #1 on: July 23, 2013, 06:06:06 AM »
Yes they do. AF accuracy depends on all the mechanical parts lined up properly and through use, wear and tear happens in the movable parts and degrades the AF accuracy gradually.

Main mirror has two hinges connected to the mirror box, two stoppers to rest on.
AF submirror has two hinges connected to the main mirros, one or two stoppers to rest on.

For each picture taken the mirrors have to swing up and down in rapid motions. The hinges can get worn, creates play. The stoppers can be knocked out of position. Both will affect the mirrors' position and angle.

When that happens, if the mirror box has means of adjustments, then can be adjusted to gain back some performance, otherwise nothing you can do about it unless replace the entire mirror box assembly.

Electrical adjustments can also be done but when doing that on a worn mechanical system, it's just a band-aid solution. Sooner it will be out again.

And if you have to ask, I know what I'm talking about (picture showing main mirror hinge position adjuster):


I've completely dismantled my 1D Mark III to fix a mirror problem. Whole set of images:
http://funkyrider.minus.com/mblciPXA9p
http://funkyrider.minus.com/mbnjGRNB2x

Even top of the line 1D do get out of focus by various reasons. However they are all metal on the construction and are fully adjustable, which makes the cost of maintenance relatively low. You can fix instead of replace most of the time.
« Last Edit: July 23, 2013, 06:14:47 AM by BozillaNZ »
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bycostello

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Re: Question regarding focusing
« Reply #2 on: July 23, 2013, 06:23:41 AM »
yes you can send it off to be calibrated...  sure it isn't your shutter speed though?

wsmith96

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Re: Question regarding focusing
« Reply #3 on: July 23, 2013, 08:00:58 AM »
Thanks for the confirmation.  As mentioned earlier, I'm not ruling me out as a poor photographer, but I do find it odd that I'm getting fewer and fewer keepers.   Given the age and type of my camera, I'm not sure it's worth the repair rather than obtaining a new one.  But before I go that route, I'm going to continue to experiment to determine if it is me or not.

Thanks for your replies.

-w
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m

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Re: Question regarding focusing
« Reply #4 on: July 23, 2013, 08:08:17 AM »
I've completely dismantled my 1D Mark III to fix a mirror problem. Whole set of images:


made my day  ;D


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Re: Question regarding focusing
« Reply #4 on: July 23, 2013, 08:08:17 AM »