Canon eyepiece extender ep ex15ii
For most canon eos series dslr except the 7d and 1 series the ep ex15ii eyepiece extender extends the cameras viewfinder by 15mm thus bridging the gap between your eye and the viewfinder this allows operation of the viewfinder without the needing to press closely to the back of the camera and is more comfortable to use the viewfinder extender also reduces the image size which can be useful in assisting composition