Dust or pollen inside this lens is common problem so I finally removed the front element and cleaned it, but even after this procedure I have the very same specks in a video as before. So I guess it's the heavily polluted second element - but I'm not sure if I can clean it. Someone mentioned that these elements are coated, but I can't find any documentation/evidence. Blower was not enough.
Can I clean it as normal front element lens?
EDIT: So it's the dirty sensor. I set F22 and made video with 18-200mm and 55-300mm and the spots are same.