To any photographer advanced or amateur, nothing is more satisfying than a clean crisp properly focused and exposed photo. So when you purchase a new piece of equipment and you are so anxious to try it out, you rush outside and blow off a couple of dozen photos. You return to your computer, download and open each file. Only you are disappointed photo after photo. You know you did everything correctly yet still something is off.
Canon EF S 55-250mm IS STM
You go out again and try and still get the image above, and you think man I am really off my game. So you attach another camera body to that lens and you get the same thing. It occurs to you UhOh I have a bad lens. Now I don’t know if any of you have ever tried to return a lens due to the focus being off but it is not easy. Unless of course you are pro-user and the manufacture hates bad press from a well known pro. I have been doing this a lot of years. Though Photography is not my day job, I have always had a camera with me since I was 15. I shoot photos every day. I know a bad lens when I get one.
At any rate, I had just purchased a Canon EOS 80D and I started digging through the menus to see if I had anything out of whack. New to the camera I hadn’t spent the hours required to go through every single function. But I stumbled upon a custom Function “Auto Focus Micro Adjustment.” Before I touched anything I researched and found a PDF file on CanonUSA website regarding this feature. “Canon EOS AF Microadjustment Guidebook”
The following Canon EOS Cameras have this adjustment capability:
50D, 70D, 80D, 7D, 6D, 5D Mark II, 5D Mark III, 5DS, 5DS R, 1D Mark III, 1Ds Mark III, 1D Mark IV, 1D x and 1dX Mark II
As you noticed from the list above none of the Rebel lineup has this capability. The Lens in question is the Canon EF S 50-250mm IS STM. Granted it is a low level kit lens bundled with my 80D but look at the photo above 70mm 1/125 @ f4.5 ISO 400 about noon on a sunny day. The image is zoomed 150% and cropped for detail. That is unacceptable.
Now, I read the Guidebook I mentioned earlier and set off to adjust the Autofocus for this lens. Each lens is serialized so once you make this adjustment, every time you place the lens on the camera the adjustment is automatically made. After (2) hours and about 30 photos later I was able to accomplish the result below: 70mm 1/165 @f5.6 ISO 400
More about the how to and tediousness of making this adjustment in a later post. In the mean time Look for Guide Book on CanonUSA website and give it a read. Hint: connect your camera to your computer and remote shoot. You can instantly review adjustments made. I mounted mine on a Slik 400DX tripod with a Slik AF1100E Ball head. Used mirror lockup. More on this later.
A side note. I discovered I had another of the lenses (from another kit I guess) I mounted on the 80D and the T6i and it works just fine…..imagine that. I guess I had a bad lens but not so bad it couldn’t be corrected with the 80D micro-adjustment feature.
DigitalDiem - Carl Grimes Photography 