I already have 12-40/2.8, PL25/1.4, 35-100/2.8, 75/1.8, Olympus 60/2.8. In terms of usage, 60/2.8, 12-40/2.8 is the most and PL25/1.4 and Oly 75/1.8 is the least. After I look thorugh robinwong's blog I like his portrait shots with 45/1.8. Will it be benefit by adding 45/1.8 to my kit? Currently only Pana 35-100/2.8 cover for that focal length. Your comment is really appreciated.