Depending on the hike, I'll go as far as bringing along my Nikon D810 with Tamron 15-30mm f/2.8 and the iOptron Skyguider pro on my carbon tripod. That's ten pounds, but I'm only 75kg, so I can afford that
When we went trekking in Nepal, I brought the Nikon with three primes and a little tabletop tripod. Still about 6 pounds, but we had personal porters on that two week trek. (I gave the guy a 100$ tip because I was so grateful..)
And, yeah, that's the moon in the frame. No tripod used, shot while walking at 4 in the morning at around 5'000m above sea level. That's why I love my DSLR with f/1.8 primes... lol
In Laponia (Northern Norway and Sweden), I only brought the Nikon with the 24/1.8 and my 58/1.4 on the longer hikes. The tabletop tripod for some panorama shots:
Shot at around 11pm, during the midnight sun period.
However, I just acquired a new toy, and at a ridiculously low price for that brand, that I'll bring along every time from now on.
Around 1kg including the tripod and an amazing sensor/lens combo to take beautiful snapshots on longer hikes.
smartphone snap edited to taste