This is actually a thing called Digiscoping. Search Digiscoping adapters on Amazon and you can attach your cellphone to binoculars. I actually do this as a hobby, that is, doing wildlife photography on a cellphone, which usually requires a telephoto lens. Not to hijack the post but you can see the results on my IG page at theCronicBirder. I have some reels that show the zoom effect. I use a spotting scope instead of binoculars to get a farther reach.