I do enjoy surfing photography. I currently use my 75-300mm and it doesn't preform that well. It is either overcast or sunny outside (day time) when people surf and its not indoors so... What canon lens do you propose $2,000 or less for this type of photography? I was looking at the Canon EF 100-400mm f/4.5-5.6L IS USM At F/5.6 I am guessing on a sunny day I would get F/5.6 at 1/800 at ISO 100 or on a overcast day I would only get 1/200 ISO 100 at F/5.6 or 1/400 ISO 200 at F/5.6 right? Which is still pretty slow especially for this focal length of 300-400.... I like the focal length of 100-400 but I fear it may be too slow... Any comments or suggestions? BTW: This is for information only! Futuristic preps, I don't plan on buying a lens anytime soon (no money).