...removal of cross-threaded uv filter stuck on Canon EF 17-40 f4 lens

Jul 12, 2013
I am going through many of my EF lenses to see how well they 'work' when connected to an M6 via an EF-EFM adapter.

A lens I only use occasionally (because the 'killer app' of the M-series--the 11-22 EF-M lens, yields great wide-angle images with the M) is the Canon EF 17-40 f4 lens; and before testing it with the M6 I attempted to remove the uv filter which has resided on the lens for at least a couple of years.

Sadly, the filter could not be removed; using Mr. Google's suggestions and trying jar top removal tools, rubber bands and leather shoelace,s and even a bit of cold weather did not enable the removal of the filter from the lens.

An individual at the bottom of this link (https://www.photo.net/discuss/threads/cross-threaded-lens-filter.438251/) described how he removed a filter that had been cross-threaded to a lens. His way worked for me, too...after I figured out that was my problem.

I took a look at the 17-40, at sure enough, the 77mm filter was on a bit crooked. With the aid of a kind of scalpel-like tool that has come in handy for taking (prying) apart watches, phones, toys and laptops, I was able to wedge the scalpel into the tiny crack between the filter and the lens...and then carefully slide it toward the other side of the lens, where there was virtually no space at all. Just a bit of wiggling...and a tiny snap (!) was heard...and easily removal of the uv filter was accomplished.

...this post is hopefully an unneeded tip for CR readers--you've helped me plenty.