As a photographer, I try really hard to make sure I’m only using gear that is reliable. K&F has done a great job of being a reliable company for budget-friendly camera gear. I have some of their other pieces of equipment and I continue to be impressed by both their dedication to superior build quality and attention to detail in their products. I found that the filter screwed right onto my lens without any issues and I was also able to remove it without any problems. Unfortunately, I wasn't able to capture a long-exposure because I don't live near any waterfalls and at the time when I got this filter, the weather really wasn't cooperating with me much. I did, however, hold the filter up to the lens without screwing it onto the lens so that I could see the difference between the image with the filter and without. With this type of test, you can clearly see a correctly exposed image and one that is darkened quite a bit with showing only the ‘hot’ spots of light in the photo. I did take a few shots with the filter installed and I noticed that there was no edge vignetting issues and because the glass is high-quality, I didn’t notice any ghosting either. All in all, this is a really nice option for a budget-friendly ND lens filter.