Canon Eyepiece EP-EX15 II

I was worried about glasses smudging against the viewfinder, but the 15mm extension gives just enough clearance. My eye relief is much more comfortable now, and the 30% reduction in magnification makes framing shots much faster.

Finally, a viewfinder I can use without smudging the screen with my glasses. The 30% reduction in magnification took a minute to get used to, but now it makes composing shots so much easier.

The 15mm extension keeps my nose off the LCD when I'm shooting low angles, and the 30% magnification drop makes manual focus feel far less strained during long sessions. It clicks on securely and doesn't wobble, which is exactly what I needed for my old body.