i know this has been covered brand by brand but i was wondering lets say..
It is a filter you found and there is no brand, is there a objective way to test if it a good filter?
For example, Kenko makes really cheap filters, non coated (basically like a mirror if you look into it), to the ZETA series that is quite good.
I've seen some youtube videos that say that if you can see a green/purple/pretty much any colour besides white reflection off it, it is a decent filter. And as well as the amount of reflections.
Is that it? Any other way to tell without being biased by the brand?