Inexpensive 1970’s golf rangefinders are all over eBay and really useful for hunting if you don’t want to carry more batteries….I got to work with Del Wiseman, an old school solar astronomer, when I was in HS. I recall he mentioned optics on battleships when discussing polarization.
I have a big German Ww2 artillery rangefinder. Most accurate if you want to backpack a sewer pipe with you!
Sirhr