Canon ER-h Eyecup

Rotating the eyecup to match my shooting angle keeps stray light out of the viewfinder exactly where I need it, and the asymmetrical shape is a subtle but clever design choice.

Installed this on my R3 and the 360° rotation is a game-changer for switching between vertical and horizontal shots without readjusting. Blocks out stray light perfectly when I’m shooting outdoors in bright sun, which was my main reason for buying it.

The asymmetrical shape really does cut out glare when shooting in bright sun, and the 360° rotation locks solidly for vertical or low-angle work. Only gripe is it’s a bit stiff to twist at first, but it loosens up after a few days.