If you are wearing glasses, especially powerful ones like me, shooting on the sunny day is hard challenge. Yhis eyecup takes all flare away, making easy to shoot through viewfinder. Of cource it is not ideal solution: it covers half of display (you can't fast preview your shots and reduces viewfinder coverage (hard to see corners). If camera's diopter is not enough for you and you have to wear glasses I recomend this as perfect solution for value/price.