Hi everyone.
Short summary of my question:
For multi-day backpacking trips in continuous precipitation/high humidity with temperatures of 0-10 C (32-50 F), what’s your insulating layer/jacket of choice? This is specifically for being in camp/rest breaks for taking pictures. Intended to be worn under an outer shell.
I’m debating between the Patagonia Nano Air, Arcteryx Atom LT and Atom AR. Open to other suggestions or ideas.
Back story:
First time post, just joined today after an “eye opening” experience during a 5 day backpacking trip in Kootenay national park in Canada.
I’m an experienced backpacker, but the vast majority of my multi-day trips have been in either dry conditions or snow, not rain.
My normal setup is a Smartwool 150 base layer, an Arcteryx Fortrez fleece, a lightweight down jacket and a Marmot Minimalist rain jacket. During this past trip, it rained non-stop for four days. During the hiking phase, I only wore my base layer and the rain jacket with the pit zips open, but sweat through my base layer. At camp, the dampness and rain rendered the down useless, and I was cold to the point of shivering at times. The fleece wasn’t warm enough to warm me back up. Admittedly, I made the mistake of not immediately swapping out the sweaty, wet base layer for a dry one.
When hiking, I get warm super easily, and feel comfortable in just my base layer down to 0 degrees C while moving. I only ever need the insulating layers in camp or during stops. I do a lot of photography, so usually put on an insulating layer and walk around slowly taking pictures.
Any advice would be greatly appreciated.

