I put the K&F 95mm MC UV Filter on a 180-200 zoom lens to provide some protection for the glass at the front of the lens. I have noticed no odd coloring or decrease in sharpness when using this filter and I was quite happy with it.

I got back from a photo shoot in pouring rain and when hurriedly pulling my camera backpack out of the back of my truck, I accidentally knocked the 180-200 lens (in a dust cover only) out of the backseat of my truck. It fell about 3-1/2 feet to concrete and landed with the lens and filter pointing down. It bent the filter ring in about 1/16 of an inch, knocking the filter lens out of the filter ring but the filter lens was intact. The filter ring was still in place on the lens but the front ring of the lens was also bent, but the lens glass was intact and undamaged. I had to send the lens to the manufacturer to have the filter ring removed and the front lens ring repaired, but the filter really helped to prevent major damage to the lens.

I immediately went and bought a second K&F 95mm MC UV Filter and put it on the lens when I got the lens back from the manufacturer. I also bought a padded case for the lens. The attached photo was taken with the 180-200 lens with the K&F filter on the lens. The photo was compressed down from 50MB to 1MB, so any loss of sharpness is due to compression, not the filter.