I believe my filter might be defective. I couldn't figure out why I was getting a red to blue gradient on all my astrophotography images. I'm sending a sample image. I thought at first it was because of the street lights, or maybe my camera was defective or maybe my telescope needed collimated. After experimenting around for a few weeks it finally came down to it is the filter. It's not like I have a clear night every night to test this thing. But I see it only had a 30 day return policy. So apparently I'm out of luck.
Update: I did report this to svbony and they immediately sent me a new one even though it was past the 30 days. Initial testing shows that this new filter is working correctly. I will change my review from 1 star to 4 stars for their customer service response.