osprey or young red tailed hawk?

by richard
(sf bay area)

I was taking pictures of one of the adult pair of red tail hawks living in our neighborhood yesterday and this bird did a few circles far overhead. Our original thinking was that this was an osprey which we also have in the sf bay area, but when we later looked at the pictures and went to the bird books, it also looked like a young red tail which is white and black before their brown/red feathers come in. Also, to us it looks like the osprey has curvature along the front edge of its wings while the red tail front edge is pretty flat as in the picture...so that plus the adult pair in the area made us think this must be their young offspring..but we are not positive so I'm asking the experts..

young red tail or osprey??