My son and I climbed up to about 10,000 feet on Mauna Kea on Hawaii for Sunset. Its about 900 feet above the Visitor Observation Center, I knew I couldn't bring my pack with all my gear, zoom lenses, primes etc. So I grabbed my Canon 1DX mk II and my Canon 16-35 2.8 L III. Off we went. It was well worth it.