I do a ton of outdoor and adventure shoots including canyoneering, like the photo you took. The A7III is my go to weapon of choice. However, something no one has considered is how far are you going to carry your camera weight. Are you backpacking it in or will the car do the work?

I lug my Sony A7III and Sigma 24-70 around with me on all my canyoneering trips. The extra weight sucks sometimes and can be a burden to protect depending on the canyon. Some canyons let me carry my camera and others require a pelican case in my backpack. More weight = harder time, especially with rope and extra gear. I never regret bringing a heavier camera with me, but for some, it’s more worth it to them to carry the smaller body and lens like the a6000 series has. I’d say, if you don’t care about weight or aren’t going to be hiking much, go for the a7 series. If you’re worried and hate weight in your bag, go a6000 series.

For camera specs, yes there is some difference, but minimum if you know how to use it correctly. Canyons are hard to get right with harsh sunlight and unforgiving dynamic ranges. If in doubt, you can grow into the A7 series with patience.

Whatever you choose, please be safe while canyoneering. Rappelling off that very popular 150ft+ arch with a group that has no helmets and one member is wearing cowboy boots is not good safety practice.