Ditch the filter !!!
Not really, ignore the headline, I think it’s a really good idea to keep your expensive glass protected. A simple uv or skylight filter over the front element of your lens is a great idea, I mean which would you rather scratch or damage a £20 filter or your expensive glass. It’s a no brainer really.
There is however a time to ‘ditch’ the filter. Shooting straight into the sun, photographing a fabulous sunset, a bright moon at night, in fact anything where there is a point light source in the picture or a bright source of light pointing straight into the lens. With the filter on there is much more chance of flare or ghosting than without, it happened to me a few nights ago when I photographed the moon, it wasn’t bad but it was there, a little light coloured flare creeping in.
So this is the answer, keep the filter on to protect the front element of your lens except when there is a bright light source in the picture.