I'm not sure if any one of you have noticed this yet, but I just got my Hoya R72 filter. What is this, you say? For the sake of keeping it simple, it's IR, or infrared photography.
As you may have seen on my first couple of shots with the filter, you'll notice a lighter circle in the middle, and in the caption of both of those pictures, I explained that I didn't know what it was, and if anyone had any ideas on how to fix it, that they should contact me immediately with a suggestion.
Anywho, I was browsing online, seeing if anyone else had this problem, and what do you know?! I'm not the only one. I guess I'm not that special...