Can I use a Nikon HR 2 Rubber lens hood on my Canon 50mm-f18 lens?
Can I use a Nikon HR 2 Rubber lens hood on my Canon 50mm-f18 lens?
I think if you put both of them on the road and a car runs over it, they will break into a million pieces
Maybe.
That generic lens hood has a 52 mm filter thread and your Canon 50 mm f/1.8 lens has the same thread size. All you can do it try it and see. While it will screw onto the front of your Canon lens, whether it will cause vignetting can only be known if you do some tests using that lens hood
You should be fine with it. If the hood had been designed for a strong lens, say a 200mm, then it would be too long and cause vignetting. However, since the HR2 is a generic rubber hood for a 50mm lens, you won't have any problems putting it on any other 50mm lens. However, put that same hood on a 20mm lens, and you'll get vignetting because it's too deep.
If it fits then why not?
Check the corners first.