I have been a river guide and private river runner in Grand Canyon for 47 years, capturing images that whole time. I have hiked many miles but mostly from the river up and usually day hikes. Since boats don't care about what my camera equipment weighs, my recommendations my not work for you, but it's a place to start. I use a full frame Canon camera (different models over the years) and carry several lenses. The one I use most often is Canon's 24-105mm f4 L IS lens. It covers probably 65-70% of the situations I encounter. I also use a 16-35mm f2.8 L lens. It comes in handy in the narrower side canyons which can also be darker. I use a 70-200 for wildlife, mostly Bighorn sheep, lizards, and birds, although this past summer there was a black bear down at the river's edge. Those three lenses cover 99% of everything you will encounter. The only other recommendation would be a Macro lens, or have one of the other lenses have macro capability. Depending on the time of year, the monkey flowers and columbines along the streams, the cactus flowers, and the maiden hair ferns near springs can be gorgeous. If your trip is early in the season (the North Rim doesn't open until May 15th), you'll see more flowers. If later in the summer, more wildlife will be down at the river or near side streams. In any event, the canyon below the rims is constantly changing with the time of day and weather conditions. The light reflecting off the river and the canyon walls intensives the color on the opposite wall. It's a phenomenal place. Enjoy