Filters & Microadjustments

When I bought my Canon 7D in November 2009, I bought my lenses without any UV filter. I already had some Hoya Pro 1 and Kenko Pro UV filters. I also spent a couple of hours to calibrate the lenses. After that, I immediately went down the street to make some photos and — Disappointment! The photos were OK, but nothing to write home about. Did I get a lousy camera? Where the lenses crappy?

I removed the filters, to see if they were the cause and no improvement. Five thousand dollars, that’s a lot, especially for a “crappy” system. I checked around the web. Many people blaming the filters. “Everybody” was recommending B+W filters are being the “only” good filters. So a few hundred dollars on the B+W filters. The photos were good.

The summer heat started in Vancouver, I decided to remove my filters and make photos without the UV filters. What a disaster! A large number of photos were out of focus. Far too many. Was my focus out? Before complaining, I decided to redo the focus Micro Adjustments for my most used lenses.

Lens	MA with UV filter	MA without UV filter
70-200/4L-IS	+1	-3
17-55/2.8	+2	-4

Bingo, what a difference!

I wish Canon had their drive AF microadjustment like the E30 Olympus. Each focus point can be micro-adjusted. Each focus point is adjusted both at the long end and at the short end of the zoom.