RE: Age of deer
The buck on the right definitely looks to be the older of the two. Heavier in the front shoulder, shorter looking legs due to a heavier body.
Too early in the year for age guesses. You can get good estimates if you can get pictures of these two in October when they have filled out their bodies and necks as they get close to the rut. If the buck on the right is 3 1/2 or 4 1/2, he will look much heavier just before the rut than he does now. If he doesn't fill out by October, then he really is only 2 1/2.