Originally posted by oldjohn I also agree with the use of the collapsible rubber hoods. They can be obtained at Adorama or B&H for very little cost, I believe around 6-7 dollars. Obviously, you need to order for your filter size, but they are available in most sizes. They can just stay on your lens and collapse for easier storage in a camera bag.
I use a rubber collapsible hood on all my primes; Image A 28mm, FA 35mm, FA 50mm and D FA 100mm macro. I love the thing. It's takes up virtually no space in my bag and I can add or remove a filter or cap very easily by folding it back. I bought the standard version because of the 28 and 35mm, but if you're using it only for the 50mm you could probably get a telephoto. I don't think it's necessary though. The standard hood does the job and is very compact. I also have the Pentax square hood for the 50mm, but it doesn't fit on the 28mm unless I use a filter, it won't accept a lens cap and it doesn't let me access the CPL.
I bought the three-stage rubber collapsible because I broke the hood on my 55-300 and I like it a lot too. The Pentax replacement was robbery, so I was glad to find the rubber replacement for about 1/8 the price.