Autofocus Microadjusting & Testing my Canon Lenses

For years I procrastinated on microadjusting my lenses to my camera body. I knew it probably worked, but the thought of having to learn this new skill and possibly screwing up my autofocus (AF) in the process was too much.

Once I got over being stupid, I called my friend Rob and we set up a time to calibrate my gear at my photo studio. He brought over his LensAlign chart and we successfully calibrated several of my lenses. This is easy!

There are several great web pages dedicated to microadjusting lenses (including an excellent .pdf by Canon) so I won’t go into the specific process here. Instead, I’ll just mention my general thoughts on the system of calibrating.


After working twice with Rob at my studio, I feel I firmly grasp the entire process. Which in essence is carefully shooting a ton of frames and deciding whether AF is perfect, front-focused or back-focused. You then use the Canon menu to calibrate individual lenses to the body. I then decided to make my own DIY chart to adjust my lenses as needed and I highly-recommend doing this if you’re into precision focusing.

I found a brilliant, free DIY focus calibration chart and built it out as carefully as I could with materials I already had in the house. Building the chart felt like I was back in college working on a 2D or 3D Design project for art school. Within an hour I had an absolutely perfect chart and a smile on my face!


After testing, retesting and testing some more I finished calibrating all my AF lenses and noted what the micro adjust is for each. 


All but my wide-angle required micro adjust because of back-focusing. The range of micro adjust is between  -1 (on my 135mm) and -13 (on my 85mm). Nothing terribly shocking in those numbers, but certainly worth fixing.


My next step is to microadjust my backup DSLR Canon body. I’ll be curious to see how the numbers compare.

Micro Adjust target
Some lens testing charts I printed at home