What do Geeks do on their day off?

By Cris | June 5, 2015 | Comments 0 Comment

They calibrate their camera and lenses of course 🙂

I’ve been incredibly happy with my Canon 7D mark II since I got it… mostly.

There has just been a niggling feeling that the shots I’m taking should be just a touch sharper. Now I’ll be honest- in general it takes fantastic pictures, but I am occasionally what they call a “pixel-peeper“- I zoom in to my pictures on my computer when I’m editing them way beyond where you normally would to see if the focus and “IQ” are as sharp as they could be, and some of them have not been as good as I’d hoped they would be with this camera.

What was particularly bothering me was shots with my favourite and faithful 17-55mm f2.8 lens- they just didn’t look as good as they had on my old 70D (or my 60D before that). So, after a little research I ordered some focus calibration targets from Amazon that allow you to see exactly where the camera is focusing and how accurately (if you’re interested, the whole procedure is nicely described here and here).

One of the awesome things about the 7Dii is that it allows you to register all your lenses to the camera and then lets you micro-adjust the focus of each lens and store it so that each time you mount that particular lens on the camera it will remember the setting, and it even lets you calibrate a zoom lens differently at the wide and telephoto ends and it will automatically adjust for everything in between.

What all this basically means is that sometimes a camera and body will just be a touch out of sync, so that the auto focus system will think it is focusing correctly when in fact it is focusing just in front of where it should be (front focus), or just behind (back focus). It’s not surprising that with mass-produced cameras and lenses that this will occasionally be a problem- I’ve been very lucky so far not have had this be a problem- but I suspected that the 7Dii may have an issue as it is supposed to have an auto-focus system that should blow the one on my previous camera (the 70D) out of the water, and it just didn’t seem as much better as it should.

So, after a happy couple of hours with my new target, some studio lighting and my camera mounted on a tripod and shooting tethered to a laptop (so I could quickly and easily zoom in to look at the results) I’m pleased to report that indeed there was an issue with the camera front-focusing with the 17-55mm (and even a little with my new, red-ring 24-105mm, though not as much). My prime lenses (fixed focal length- non-zoom) are all pretty much spot on, but the zooms all seem to be off by varying degrees. I say “pleased to report” because I was able to adjust all of them so that they should now be just right 🙂

So, I shall see what the difference is when I take the camera to the woods tomorrow and then shoot at the parish picnic on Sunday. As I said, the difference is very slight and really wouldn’t bother anyone but me and my pixel-peeping, but it’s nice to know that I wasn’t crazy in being a tad dissatisfied and that I have hopefully fixed the problem.

Here are a few (phone) pictures of the process-