I've spent four days in the Alps - fantastic for landscape and flowers. I wasn't going to focus on wildlife, mostly because I also wanted to relax - if you have too many expectations for just a few days, it's going to become as a sort of job.

But, unexpected, I had the chance to see a fox predating a marmot, at a relatively close distance, well within the range of the Sigma 150-600mm. I hadn't use it for months, but it was in its place in the larger bag, with all the needed padding. Unfortunately, when I mounted it on the camera I realized that the protective UV filter was broken - a threefold crack originating from a single point on the border, probably a relatively small hit but with the proper orientation to maximize the damage. The glass didn't fall apart, so no problems with fragments, but in any case the time required to unscrew the filter made me miss the shot.

Anyway, so far it was just a divagation. Glad that the filter absorbed the hit and the lens was ok, I ordered a replacement B+W filter at Amazon. What surprised me is that I found different versions (same size, 95mm, but different names)...

https://www.amazon.it/Filtro-B-W-filtro-UV/dp/B0001GJCFC/ref=sr_1_3?s=electronics&ie=UTF8&qid=1529081769&sr=1-3&keywords=b%2Bw+uv+95mm

https://www.amazon.it/66-045110-Ultraviolet-camera-filter-95mm/dp/B0000BZLCL/ref=sr_1_1?s=electronics&ie=UTF8&qid=1529081769&sr=1-1&keywords=b%2Bw+uv+95mm

https://www.amazon.it/95-Clear-MRC-007M/dp/B00L7R7G9S/ref=sr_1_4?ie=UTF8&qid=1529080837&sr=8-4&keywords=b%2Bw+uv+95mm

... at very different prices: 65+10€, 119€, 143€. I bought the previous one at eBay's for 85€. I suppose that the different prices are mostly to the fact that one is the MRC, a new version with improved multi-coating. Since I didn't have problems with the old model, I bought the cheaper one (the point is that there's some sort of disgrace with this filter, as it was already a replacement because the very first bought one was dropped and broken - so I really wanted to save some money).

My doubt is whether the cheaper is a fake one. The vendor is from Germany, so there should be no problem... but do you think I'll need to run a sharpness test to be sure that it's an original one?

Thanks.