I've used it once and I paired it with a 10 stop ND filter with this and I was able to set my camera set at 30 seconds, f11 and ISO 50 in the middle of the day but with the 10 stop I could only get it to 10 seconds, f11, ISO 50. I was surprised to see that when I got home to edit the photos there was no noticeable loss in sharpness with both ND filters on and this being a variable ND filter they're notoriously known to be less sharp than a constant ND filter. I can't wait to test this out on a waterfall but being that it's summer in San Diego right now I'll have to wait to try it out but along the coast I prefer the 10 stop ND filter and being able to drag that shutter longer. The front of this variable ND filter is quite large so your lens hood won't fit on there which can be an issue with unwanted lens flares but the K&F 10 stop ND filter I used with this you're able to mount the lens hood still. I received this filter free of charge to test it out so take my review with a grain of salt but if you do choose to get this I highly recommend getting a 10 stop as well because you'll be limited to 2-3 second shutter speeds with this alone at it's darkest setting in the middle of the day where the sun is bright like it is here in Southern California. I forgot to mention that there are notches on the side and tells you the minimum - maximum darkness and each stop between so there isn't any guess work involved but I do like the fact that I was able to set my settings I wanted and just rotated the front element until my camera read that I was properly exposed.