Good information for beginners and learners.
As for as control mist/ moisture forming on to lens while taking photo against direction of fall of water, good to umbrella at an inclined angle so as to avoid blocking mist at the same time allowing lens to capture full or desired view of water falls (but need some one to assist)
As for 70-200mm lens usage the need is where we could not reach for close-up shots in case of shot at wild animals, birds & political leaders in large crowed gathering places etc., or else go two camera one with 70-200mm or other 28-55mm.
