Printable View
Where can I find a good tutorial on how to perform a micro adjust for my lenses? I looked around a little on this forum without success. I have a 50D and 4 lenses; 10-22, 85 f/1.8, 24-105 f/4, and a 70-200 f/4 IS. 'd like to get the most accurate focusing possible, especially when using the 70-200at the MFD.
I think there is a small tutorial in Bryan's review of the 1D
Mark III.
I printed out a resolution chart from the internet, then take a bunch of pictures. I first tried big gaps, like -20, -10, 0, 10, 20. I picked the best adjacent pair among those, then did finer adjustment (ie, if -10 and 0 are the best, next try -10, -8, -6, -4, -2, 0).
I used mirror lockup, a flash, and a tripod. I focused with the center point and used only the center of the image to judge sharpness (because if the camera isn't square with the chart, focus in the edges will be off).
If you are most interested in af performance near the MFD, then do the callibration near the MFD. I will not be exactly the same throughout the range.
If you are really looking for the most accurate focusing possible, I recommend a LensAlign Pro.
http://www.lensalign.com/
After trying as many paper targets as I could find, I was not happy with my results. I finally broke down and purchased the LensAlign Pro. I use a lot of f/2.8 so out of focus is a lot more noticeable with the shallower depth of field. I think that you will really appreciate where you will get with your 85 f/1.8.
I went with the "B-Stock", but mine has no noticeable flaws. I did not purchase the long ruler kit and it works fine with my 70-200 f/2.8 IS. I would recommend you go that route. Given what you have in gear, it is a relatively small purchase that will work with your current gear as well as new purchases.
Hope this helps, good luck,
Chris
If you want to spend the cash, there is always Lensalign ...
http://www.lensalign.com/how-lensalign-works.html
http://videos.lensalign.com/LensAlign/LensAlign-Video-User-Guide/6830310_fnpyr
I have been debating on this one since I still haven't done anything with any of my lenses. Well, at leastthis gives you an idea of setup and what it entails.
Denise