BTW ND400 will bring 12 stops of exposeure so if ISO 200 F14 AND 3mins I think the building lights wont go chao tar aka over exposed. Never try b4.. any 1 who uses ND400 care to share with me? New to my ND400 with HMC.. haha.. very good filter.. Bought at $80
Nice picture. Good idea. I dont think comments about over/under are valid: what you wanted as shadows are shadows, what as highlights are highlights. So your picture is most OK!