Lens hood

Is there an alternative lens hood for the 50mm f/1.8 besides the Canon one?

You could try one of the rubber types that screw onto the filter thread. They're not expensive but would work fine on your 50mm lens. In theory virtually all the Canon lens hoods are tailored specifically to a particular lens but they do tend to be expensive for what they are.

I second Bill's recommendation. I use a Hoya rubber adjustable hood:

http://www.bhphotovide​o.com …EG&addedTroughT​ype=search

I have the 58mm version (attached to my 50/1.8 with a 52mm step-down ring) which I use on the rare occasion I bring out the 75-300IS zoom.