+ Landscapes
+ Indoors in buildings
+ Portraits of the immediate vicinity with a meaningful background
For wide-angle shots in low or limited light conditions, this lens is absolutely geeeignet. Great shots are possible, the colors are mapped nice with versatility.
Yes, the price is high, even compared to the EF 17-40, but the light intensity simply justifies this price. I do not regret this investment and have the lens, being there when I have time for a change of objective.