Lens Hood for Zenitar Fish Eye Lens

really like the lens but it has its faults.
lens cap is easily knocked off
the front glass is really easy to smudge with a stray finger
no space to attach filter to the front.
the rear filter protrudes into the path of the mirror
 
the first two problems are helped with this diy lens hood made of 2mm craft foam and electrical tape, no adhesive touches the lens anywhere, it holds on by friction around the focus ring,

the first layer is the same size as the focus grip , then the layers get larger and still rotate freely around front of the lens.
 
my camera has an apsc sensor so i need not worry about loosing the corners of my images.

and no i cant see the distance marking on the ring , but this lens has a short throw and preforms badly at low f numbers.