I've been using this filter through the Summer and I'm very impressed. The filter itself is very well made and solid. I received it quickly and packaged well. I image in Bortle 8/9 skies just outside Chicago, and had been using a CLS filter. The entire background would blow out with any exposures over 3 minutes. With this filter, I've done up to 7 minute exposures and I'm not even close to half way on the histogram (using ZWO ASI071MC Pro at unity gain). I don't think I've really even hit the sweet spot yet. Straight narrowband imaging isn't an option for me, and the high-end quad band filters are out of my price-range right now, so this was a great option for me. I also had an opportunity to briefly use this filter in Bortle 3 skies on the East Veil and the vividness of the blues on a single 4 minute exposure was unlike anything I'd been able to achieve before. I'm anxiously awaiting all the red fuzzies in and around Orion, where this filter should really shine. Image examples @katorellaastro on Instagram.