I don’t think this is a good example of rent seeking, this seems like an entirely positive sum interaction with no attempts to restrict the supply.

There is a cost to installing the binoculars. That cost can be recouped by people paying a small fee to use the binoculars. The binoculars are in no way impeding your view of the scenery, so no one is being coerced into making the purchase. You aren’t prevented from bringing your own pair of binoculars.

So you're only going to be spending your spare change on the enhanced zoom if you believe it’s worth more than your unimpeded view. You get a view you wouldn’t have had otherwise, whoever installed the binoculars earns a small profit. Win-win.