My quickie technique is to use a target parallel to the sensor as suggested, 50X the focal length away from the camera, which is mounted on a tripod, aperture wide open, target in good light, and then let auto focus do its thing and focus. Then switch to Live view in the most magnified view. If that is in focus already, then you are done. If not, then focus manually via the magnified Live View, and then switch off Live View. Looking at the distance scale, press the AF/shutter release to initiate AF. Note which way the lens turns and how much.
Having done this, adjust the microadjustment proportionally and in the appropriate direction (which you will learn to do with several attempts.) Then, hit the AF/shutter release again to make the camera AF again (optimally from an out of focus point). Switch again to Live View in the magnified view. If it is in focus already, then you're done. If not repeat the cycle by focusing with Live View again, then switching off the Live View, then use AF while observing the lens to see how close you are (if the lens barely budges, you are very close), and then microadjust proportionally.
You will get closer and closer. And if you go too far, the lens will move the opposite direction when you press AF/shutter release after having focused in Live View.
This is faster than using files (actually taking shots), and IMHO, the Live View magnified is just as good as the monitor view in the end, or close enough.
The tripod, and a cable release help to avoid spurious results.
If your AF and Live View are in agreement, you have succeeded. At this point, the files or monitor view of the images will substantiate the result in my experience.
arty:
