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Old Sep 4, 2007, 6:43 AM   #11
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You only want to adjust the focus with the 50mm f/1.7, not the other lenses. Calibrate it with that one and see what you get if you want to try it yourself.

I'd make sure you do it in relatively good light, too (open a few window blinds to let some in if needed). It sounds like light was so low the Tamron was hunting. Don't try it in light that low, as the algorithms for a given lens (especially a wide one) may have a wider accuracy tolerance built in for low light use (i.e., it's better to be close than not have focus at all).

Remember, your 50mm f/1.7 is approximately 3 times as bright as that Tamron, so that AF sensors get a lot more light to focus with. But, you don't want to use that Tamron for calibration anyway. Use the 50mm. That' s what the techs use to calibrate one, too (a 50mm f/1.7).

It also sounds like you were not getting a focus lock with the Tamron, or you are not using the same focus point each time. You may have been too close to the target for it to lock focus, too. What were you trying to shoot (test target, books, or other)?

My preference is staggered books, since it's closer to real world use from a focus distance perspective. But, the focus chart is a popular way of doing it.

Make sure you do not have the camera setup so that it can shoot without a focus lock (it will require one by default, but you may have changed it somewhere along the way), and make sure you are selecting the center focus point when doing these types of tests.

Press the Fn (Function Key) on the back of the camera, scroll through the focus related choices and set it to Spot AF and Single Shot AF to make sure it's going to use the Center Focus Point.

Then, go into the menus (press the Menu button), select the custom menu (looks like a sun or gear), and make sure Priority Setup is set to AF, not Release.

If it's set to release instead, the camera will shoot without a focus lock. So, it's got to be setup to AF if you don't want a lot of blurry photos (if you're not half pressing the shutter button and waiting for the lock to occur before pressing the shutter the rest of the way down). That's the way you want to take all photos (half press the shutter button, wait for a focus lock, press it the rest of the way down). Setting Priority Setup to AF makes sure you have a lock first (and that's the way it comes from the factory).

I'd make sure it's set correctly and try it again. Half press the shutter button, make sure you are getting focus lock using the center focus point (you'll see a steady green light in the bottom of the viewfinder when the camera achieves a lock after a half press), then take the photos by pressing the shutter the rest of the way down.

If you're getting that much variation with the Tamron, it sounds like you're taking photos without a focus lock and light was so low it was hunting. Make sure Priority Setup is set to AF like this. But, again, you don't want to adjust anything with it. Use the 50mm f/1.7 for that if you decide it needs adjusting (and only if you decide it's far enough off to worry about). Once it works right, the other lenses should be close if you have an AF calibration issue (and you will see some variation between lenses).

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Old Sep 4, 2007, 10:23 AM   #12
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P.S.

If you want to see how the real procedure to do it works, see Pete Ganzels pages here (this is for the 7D versus 5D):

http://www.pbase.com/pganzel/maxxum_...cus_adjustment

But, again, I've seen multiple 5D and 7D users report that they fixed backfocus problems simply by adjusting all 3 of the hex screws for the AF sensor assembly equally clockwise by a small amount (usually between 1/4 and 1/3 turn corrects severe problems). So, if it were my camera, that's what I'd try with it before spending $281 to have someone else adjust it. Of course, do that kind of thing at your own risk.


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Old Sep 4, 2007, 3:16 PM   #13
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JimC, thanks for the detail procedures, I used flash for all tests, and I hear the 'beep' the confirm AF lock. I bought my first D5D less than one year ago, do you think SONY will repair it under one year warranty?
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Old Sep 4, 2007, 3:22 PM   #14
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They'll probably fix it at no cost if it's it under warranty. I thought it was out of warranty and didn't pay any attention to when you bought it.

Sony will have you send it to Precision if you're in the U.S. and they should fix a focus problem under warranty.

http://eservice.sony.com/webrma/web/index.do


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Old Sep 4, 2007, 3:40 PM   #15
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P.S.

I'd make sure you actually have a problem though. I sure wouldn't be using a flash for the tests, since a preflash may be throwing it off, and if you're using a flash for AF assist, it may even be confusing it due to reflections. I disabled the AF Assist Flash features on my 5D the first day I got it and haven't used it since. It's annoying and doesn't work that well anyway. But, even if you have the AF assist feature turned off, I probably wouldn't use a flash to test AF accuracy.

I'd use a tripod without a flash to do any tests of AF accuracy, using a 50mm f/1.7 to check it with in relatively good lighting if possible.

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Old Sep 4, 2007, 9:02 PM   #16
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Thanks JimC, I will try again. BTW, do I have to call for the RMA# before I send the camera out?
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Old Sep 5, 2007, 6:49 AM   #17
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Go to the last link I posted and fill in the blanks to create a repair ticket if you decide to send it in.

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Old Sep 5, 2007, 12:28 PM   #18
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I just sign up for the repair ticket and will send the camera out to them tomorrow. Thanks for all the help.
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Old Oct 7, 2007, 12:32 AM   #19
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I have my 5D back from Precision Camera about a month now, the AF focus is perfect. At Precision Camera, they not only calibrate the AF focus system, they also clean the sensor and update the firmware, they really did an excellent job. Everything is free since my 5D is still under warranty.

I am waiting the price of the A700 to drop little bit to get one.
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