About the location
Because it's so popular, it's even more important for serious photographers, that you are at this place during the right time. A good one is for example the midnight sun during summer, because that's usually the time when all the casual tourists already left the spot and the busses finished work.
In general it's a good idea to have a lot of cleaning cloth with you, to remove any spray from your lens. You might also want to use a shower cap or something like that to protect your camera while you are not shooting, because the direction of the spray is changing constantly. If you want to photograph the whole waterfall from behind, you will need a wide angle lens to capture everything within one image.
Don't miss to visit the waterfall Gljúfrafoss inside a narrow canyon, which is just nearby and easy to reach by foot in around 5 minutes.
