Canon 12mm extension tube

Little Grebe

I got another Canon extender last week – a 2x mk III, so I had to go try it out.  As I already had a 1.4x extender mk III, I read you could stack them to even further increase the range of the lens.  You need a Canon 12mm extension tube to stack the mark III extenders.  So with my 500mm and a tripod I had to have a play