If you don’t own a filter (UV or similar) on your very expensive DSLR lens then you should think about going out and buying one. Make sure that you get a good one, because there’s nothing worse than downgrading your lens by
putting a cheap filter on it. Why a filter? because if scratch your filter it will cost less than $100 to replace it. If you scratch your lens….
The cheap trick for today? Tape your filter. Buy some 3m black masking tape and run a line of tape once around the filter. In other words you are taping your filter to your lens. Why? this will prevent even more dust from getting between your lens and your filter!