neil64 said:Actually, you are mostly right, but UV filters do make a positive difference sometimes, even with a GoPro sensor. Judging from your avatar pic, you look like a DSLR guy, so you most likely already know this.
As mentioned, UV light isn't as big of a deal with most digital sensors we use now, but it still makes a difference most of the time, even though it's subtle (especially on a GoPro). With a UV filter, that lake shot would have probably been a little more properly exposed (even if just from the extra 1/2 stop of light or so getting filtered) and the trees and sky wouldn't have been so blown out. In that particular shot, there is also a good chance you would have seen some more blue in the sky with a UV filter. A UV filter is really only any good if you know how/why it works and know what you're doing with it. It will knock out some of the intense UV light in your images, such as bright leaves in sunlight, or a pond surface, or haze from UV light bouncing off particles in the sky, giving you more vibrant colors instead of being washed out in UV light.
Firstly, just to clarify, "I'm not a DSLR guy", I shoot with everything from a DSLR to a smartphone. If you'd like to know more about my credentials, you'll find them here, http://www.peter-evans-photographer.com/about.html
Secondly, it doesn't matter, because whether you're shooting with a DSLR, compact, phone, or GoPro, it makes no difference. A UV filter will do none of the things you've described. You're getting mixed up with some of the attributes of a polarising filter and you're perpetuating a myth. If you don't want to believe me, do some proper research and take on board the advice of some fellow professionals (like looking here for example http://www.thephoblographer.com/2013/01/11/uv-filters-do-they-degrade-image-quality/