Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: marcmccalmont on November 29, 2008, 10:12:01 pm
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Does any one have a good technique for adjusting Canon's Auto focus micro adjustment?
Thanks
Marc
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Wait about 1 week and I'll have a remarkable solution for you.
Michael
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Thanks
I'll be patient!
Marc
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Wait about 1 week and I'll have a remarkable solution for you.
Michael
Now Michael thats just teasing! :-)
I have found this method very effective in the meantime.
Micro Adjusting your lens (http://www.openphotographyforums.com/forums/showthread.php?t=4708)
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I've calibrated my 11 or 12 lenses on my 1Ds MKIII maybe 7 or 8 times. Each time I tried different methods suggested by various people. On every occasion when I re-calibrated I found there was some minor adjustments needed again. Since I documented results with each cycle, I know definitively what changed and by how much. Finally, I came up with my own flow for doing this with great precision.
What I now do is set the camera up on a firm tripod and choose a slightly slanting target so that I can see changes in DOF. Next I shoot tethered to C1 Pro. In C1, I make the first shot as the primary variant so that with subsequent shots, I can view @ 100% the change in sharpness and point of focus in the comparison viewer window. In other words, I get to see 2 images side-by-side. I shoot wide open with all lenses. When I see an image is sharper at the correct point I'm focusing, I make that new shot the primary variant so that subsequent shots will now be compared to this reference. I continue micro-adjusting focus until I find the best focus. I find this method to be the most reliable and accurate. Usually, you will notice also that when the best focus is reached, micro-contrast will also improve, on some lenses, significantly.
Please give my method a try and let me know if you find it helps your calibration. I love the ability to micro-adjust and I wish my 5D had this function. Guess I will need to buy a 5DII just to be able to do this. I will not but another DSLR that cannot be micro-adjusted.
Good luck.
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I used: http://www.northlight-images.co.uk/article...adjustment.html (http://www.northlight-images.co.uk/article_pages/cameras/1ds3_af_micoadjustment.html)
A couple of tips:
1) The lens must be wide open
2) The lens should be at its longest focal length
For reference, my lenses:
17-40L = +10
24-70L = +16
70-200L = +10
35L = +15
85L = +12
135L = +3
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I experimented using different ways of focus adjustment with my 1Ds III and found that what works for me is to auto focus (camera on tripod of course and non moving carefully selected target) then turn on live view and magnify all the way up. Focus is a snap to check this way. If the point focused on isn't in exact focus you turn the manual focus to exact focus and note whether it is further away or closer and make micro-contrast adjustments accordingly, then re check focus. this is quick, and easy. Don't know if you can find anything on the web about this method or not....I just found this works very very well and works for me. Eleanor
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Thanks for the inputs I'll give them a try
then compare to Michael's method next week
Marc
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I combined all of your techniques and had good results;
- I used the target as suggested http://www.xs4all.nl/~bvdwolf/temp/OPF/MicroFocusAdjust1.gif (http://www.xs4all.nl/~bvdwolf/temp/OPF/MicroFocusAdjust1.gif)
- I set my laptops screen at an angle
- I set maximum aperture and focal length
- Then auto-focused
- Then I zoomed in w/liveview
- Then I set the micro adjustment
- Then I verified the results with this test image and the screen perpendicular to the camera
http://www.northlight-images.co.uk/article...l#AF_test_image (http://www.northlight-images.co.uk/article_pages/cameras/1ds3_af_micoadjustment.html#AF_test_image)
Thanks
Marc