they fill up all the compartments and add up the total volume filled. As I understand, most backpack manufactures do so by having small measuring spheres, or in some cases simply dried beans. However, the way backpacks measure volume is different than their actual capacity. This is just taking the exterior dimensions and multiplying them out. If we just do the rough back of the napkin calculations based on external dimension, the Nebula has an external cube volume of 45 liters, and the Quasar at 40 liters. The quasar is slightly taller and wider, slightly but shallower by almost 2 inches.

The quasar is 19.31H X 12.61W X 10.24D IN and 28 liters The nebula is18.91H X 12.21W X 11.82D IN and 34 Liters So I'm not quite sure where you got your measurements from. I should mention that I do not have an REI or any other outdoor store nearby to check out the bags in person, so I will need to order from the internet without handling it first.

I am a bit confused, however, as the two I had looked at on their website have almost identical dimensions but a six liter size difference - with the larger Nebula having smaller dimensionsĪny other bag suggestions would be most welcome as well. Osprey has caught my attention due to the positive reviews that I've seen praising build quality and their warranty (plus they look aesthetically pleasing). Possibly, but rarely, may be used for day tourist duty or half-day hikes. The main uses for the bag will be for work, campus and as a light under-the-seat carry-on. I've been using a GR1, but would like something less tactical and with more organization. My trusty TNF Vault that I've had for almost ten years now needs replacing.

Osprey quasar