Usualy with a boar bear the ears look smaller because of the big head. You have to see enough of them to be able to tell the difrence. A male bear will grow about a third bigger than a sow?
Hope this helps.
That's tough, since young boars can look like old sows. But if you have a big boar it starts to get easier because the head is beefier and they tend to have a more burly walk. One of the nice things about Alaska is you can hunt over bait. Although some people will debate that choice, it makes for a lot fewer mistakes. You have more time to study the bear, think it over, look for cubs, etc.
Tough call to tell between a boar and a sow. In addition to the info the others have posted, try to form a triangle between the ears and the tip of the snout. A large bear will have almost a perfect triangle shape, whereas a younger bear will have an uneven triangle. Also, a female will have a shorter snout compared to a boar who will have a snout more like a german shepard's.
When placing a trail camera don't just look for a well used trail. What you want to do is look for a freshly used trail off by itself that goes from a north facing ridge, thick forest, brushy knob or some other similar bedding area to a food source. Don't forget water sources. Especially in the summer months the deer need water so look for a good trail going down too a creek surrounded by thick cover and place the camera 100 yards up from the water source.
Scent control is very important...