My walkaround zoo kit is:
- Canon 5D Mk III body
- Canon 100-400 f/4.5-5.6L II zoom lens
- Canon Angle Finder C - attaches to the viewfinder, and allows easier shots from low or otherwise awkward positions, and pretty much lives on the camera
This body/100-400/finder combination weighs around 2.8kg, which I find is just about light enough for me to carry around in the hand, or over the shoulder, on an all-day zoo visit.
I took a look at the image metadata for all of the zoo images which I've shot since I started uploading on ZooChat (about 7 years). Around 94% were taken with the 5D MkIII full-frame body, and about 88% with the 100-400mm zoom (purchased 2015). Almost all of my shots in the ZooChat galleries from the last 6 years were taken with that combination. Prior to that, most were with a 70-200mm zoom on the same body.
I used to bring along several additional lenses, such as a wide-angle (17-40) or standard (24-105) zoom, as well as a 1.4x teleconverter, but nowadays rarely carry any of these these - unless I have a specific task in mind. I do usually carry a macro lens though. Most of my wider/enclosure shots are taken with a phone.
Other stuff, usually in a small backpack:
- Canon 50 f/2.5 macro OR Canon 100 f/2.8L macro - occasionally both
- Spare battery - maybe two on a cold day, probably in a pocket
- Spare memory card
- Lens hood(s) or equivalent - for those rare sunny days in the UK, or more often to counter reflections when shooting through glass.
I've been very happy with this setup for the past 6 years, although the recent additions to the Canon mirrorless lineup do seem quite interesting, and I suspect that I may be tempted to hire the R5 for a weekend before the end of this year!