I love taking binoculars when I'm hiking, and although I've got a great pair of reasonably compact binoculars they still weigh a ton when I'm gram counting the bejesus out everything else I'm taking (I've literally hacksawed the end off my toothbrush, for what it's worth).
Is there anything out there? Or is it the classic 'pick two'?
I've got Leica 10 x 25 meets your requirements, not cheap but excellent bright optics.
A few pointers here - note what I ended up with near the bottom of the page - nice and compact. They are the 8 x 32, not 42 as I stated though
Budget is question #1
Budget is question #1
£150
A few pointers here – note what I ended up with near the bottom of the page – nice and compact. They are the 8 x 32, not 42 as I stated though
Nice! How are you getting on with them?
I'm enjoying the Star Wars-iness of these bad boys

Nice! How are you getting on with them?
It's the first pair I've owned and not really used them in anger, but pretty easy to get dialled in and seem to do what they are supposed to do pretty well tbf
Steiner safari 10x26 ultrasharp, really sharp and small and can be bought from £100ish