Top one doesn't have the filter. At least, that's my deduction. I use filters when walking around just shooting random images/ scouting locations. When doing actual work, I prefer to not, if conditions allow
This, in a way, proves my point. The bottom photo is the one without a filter. This thread wasn't about using them/not using them, cheap filters vs expensive ones... This was to prove a point.
My first set of pics proves that, 1) YES, you can tell (under very close examination) the loss of image quality using a cheap filter on an high quality lens. (or any lens for that matter)
and 2) When you are viewing the photograph under normal circumstances, you CANNOT really (it was about 50/50) tell if a filter (expensive or cheap) was used or not.
If you don't like using them, then don't. If you like using them and the ones you use are from Best Buy, then more power to you. I doubt anyone, anywhere will be able to tell the difference.
Er, but under normal viewing I did tell............
First, a1.jpg, has UV filter, second, b1.jpg, does not. IMHO