So I finally pulled the trigger on the Canon R10 last week and Im honestly kind of panicking now because I spent most of my savings on the body and I have this trip to the Everglades coming up in about three weeks and the kit lens is basically just a paperweight for what I want to do. I really want to get into bird photography and maybe catch some gators from a safe distance but I am totally lost on what glass to actually buy without going broke.

Ive been scouring YouTube and forums and everyone keeps saying to get the RF 100-400mm f/5.6-8 IS USM because its native and cheap but then I see other people complaining that f/8 is way too slow for anything that isnt bright midday sun and now Im worried I wont be able to get any good shots in the early morning when the animals are actually active. I also looked at getting an EF to RF adapter and maybe finding a used Sigma 150-600mm Contemporary but some people say that lens makes the R10 feel super unbalanced and the autofocus might be twitchy or something? I dont know if I want to deal with a huge heavy lens while hiking for hours in the heat and humidity.

Here is what I am dealing with:

• Budget is $650 max and that is stretching it honestly
• Need it delivered before my trip on the 12th of next month
• Must be able to carry it on a 5 mile hike without my neck snapping
• Use case is mostly birds in trees and some larger mammals

Should I just suck it up and get the RF 100-400 even with the slow aperture or is the adapter route with an older EF lens actually better for a beginner? I keep going back and forth and every time I think I have a decision I read a new review that says the opposite and my head is spinning. Its my first real camera so I really dont want to mess this up...