I have had this lens for a couple of months bought from Jessops and Have not used it much but will be this weekend for cowes Week , I thought I would check the lens was clean,as you do, and there is a tiny white speck of debris/dust/fluff inside the front element , I do not use filters and this speck is 100% inside the lens not on the outside....what should I do?? Ignore it??? Or wait till after cowes week and take it back???