My girlfriend uses a Brenthaven Trek backpack to carry her Macbook and large quantities of books and other things that would be a lot lighter than your camera. I am sure their Pro pack is nice too. Personally i am partial to the same company's shoulder bags, but their backpacks are the best in their class as well.
I have sleeves for my laptops, and then various messenger bags and backpacks to throw them in. 😎 If you opt for a decent sleeve, you can pick your backpack of choice without having to find a specific "laptop backpack" that meets your needs and criteria.
I transport both mine in Incase sleeves (the one for my MacBook air is all fluffy on the inside, which I love!) which means I'm free to put them in what ever bag I'm using that day.
I suppose they don't provide as much protection as a proper laptop bag, but I don't seem to have had any issues yet.