Vanguard Fabric Backpack for Compact System Camera, Black

Q: Will this bag fit as carry on once fully loaded with gear?

I have flown with it as carry on several times. It definitely is not an issue for the overhead bins. Under the seat is a little tight on some of the carriers like KLM. Delta and American have been okay. I just make sure not to over pack the front pocket.

Q: Can the alta rise 38 hold a tripod like the Peak Design messenger bag?

Definitely no! It hasn’t any external strap for tripod.

Q: Will the alta rise 48 backpack hold a 15.6" notebook computer? what are the internal dimensions?

Yes it will pretty snug. Width wise you're fine but where it will be close is length. This backpack can be configured so many different ways that a 15" computer fits, you just may have to configure it to your liking. I fit 2 five inch freestyle drones, fatshark goggles, a transmitter, batteries, tools and a 13 MacBook pro all fits with ease