I'm looking to buy a new portrait lens, but am not sure what to get. I mostly take pictures of my daughter (9 months) and mostly use my canon 50mm 1.8. I've heard that the Canon 50mm 1.4 is good, but not sure if it's worth upgrading to at this point. I am also interested in the Tamron 17-50 2.8 to replace my lens kit. Any recommendations on these two or other lenses I might want to look at? Thanks!