I know a best hiking bag requirements are as follows:

-Must be comfortable

-Must hold all camera gear I want to take

-Must have spot to place water bladder

-Must have a secure way to hold a tripod

-Must be waterproof or ability to become water proof (rain cover)

-Must protect gear well

-Must have room for extra nick naks and small snacks and such

-Must look decent

-Must not cost more then an L lens

Now we have a Solar power Hiking Bag whick is with almost all the features above.

Deatils:

* Size: 32.5 x 21 x 89cm
* Material: poly 420 D + cord veins poly+ solar panel
* Solar panel connected with the rechargeable batteries and different interface for different appliances
* Double shoulder straps
* Multiple adjustments on shoulder straps and waist straps
* The main compartment is top loading with a flap and top compartment
* Lower area is accessible by an outside zipper
* Air flow back pads for the maximum in comfort
* Side, top, middle and bottom compression straps for the most secure loading
* All stitching is folded and rolled for greatest durability
* A detachable extra Bag for increasing carrying capacity, and also individually use for carrying things
* Long-distance padded shoulder and waist straps