Yeah I would not be to eager to do it myself, im not so good with dissasembling and reassembling stuff. And there are no market for those where i live. But im fine with filter for starters, even if I end up with a modified the filter would still be usefull if same size as lense ofc.

Great, exactly what I needed to know. The Hoya is one of the most used as far as I read. Yeah long exposures and a lense with no hotspot, I found a list somewhere with a decent amount of lenses listed.