Canon SX50 Camera is an superb compact camera with biggest telephoto lens you can find in a compact camera at the moment. But it's lens is built in and the most important part of the camera. If you get a scratch or crack on the lens that would be end of your SX50. Because replacing len gonna cost you nearly as much the cost of camera. So better keep it safe. For that you can use an UV filter. It won't effect your photos and also keep your camera lens safe. These UV filters can be found for less than 20 USD and if you are crazy about quality then you can find high-end UV filters for around 40 USD( There are even more expensive filters but no need something like that for a compact camera.)
You need to buy a filter adapter along with your UV filter so you can mount it on Canon SX50 Camera. This is something I had hoped to see with Canon SX50 models but they haven't done it. So Still we need an filter adapter for mounting filters on Canon SX50. There are couple of options out there. All cameras in this series has Same size lens. So you can use Same Filter adapter you have used for SX40 or SX30 for this new SX50 too. There are 2 types of filter adapters. 58mm filter adapter and 67mm filter adapter. Recommend you to use 67mm filter adapters because Canon has built a custom filter adapter which works with SX Ultra zoom series. Original Canon adapter is way too expensive, 30 USD but at Amazon you can find similar, Bower FA-DC67A Ring Adapter for less than 10 USD ! so you can save 20 USD and buy a good UV filter along with it.
Don't go for those cheap Filter packs. You can get better quality accessories when you buy separate. Get this Bower FA-DC67A Ring Adapter and Search for a Hoya 67mm UV filters. These are very good and doesn't effect photos at all. You can buy an very good one for around 20 USD.b+w 67mm UV filter would best probably the best but it cost you 43 USD. There is a Canon UV Filter too which is around 18 USD but we know Canon do not manufacture filters so they probably buy from somewhere else and print their name on it. I forgot to mention this before, you will need a 67mm lens cap too.