Canon E de Dioptria -3

Comments about Canon -3 Diopter E:

I am nearsighted and purchased the Canon -3 Diopter E and the required EF Rubber frame (for use on Rebel SLR viewfinders). Now I can easily view the frame with my glasses on and then to 'get closer' I can lift the glasses onto my forehead and turn the small focusing wheel next to the viewfinder and again clearly see both the AF points and the framed shot. Makes things much more convenient for critical framing, and the soft eyepiece frame (similar but NOT same as standard one) prevents scratching of my eyeglass lens. Definitely worth the small expense. [...] Remember that the viewfinder has its own default -1 diopter and the small adjusting/ focusing wheel next to the viewfinder allows +/- 2 diopter adjustment, so this -3 gave me a range from -1 (standard/ stock) normal view to -5 (for my sight requirement with out glasses). If you wear glasses more than -3 (nearsighted) or + 1 (farsighted) that the viewfinder AF focus adjustment will accommodate, I would recommend looking into the diopter lenses available. Does not protrude any further than standard eyepiece frame.