I'm quite impressed with the 35L backpack. I can fit my Sony 600mm f4 lens, without the body attached, plus a Sony 300mm f2.8 lens, 2 Sony camera bodies, extra batteries, etc... in the pack along with a 14" laptop and its still comfortable to wear. We'll be using two of these packs for a three week safari in Africa in June with quite a few days of walking safari days and that will be the real test.