Nikon Aculon A211

So this is again, just a very simple review. I don't really have a way of showing you guys how they look at distance, but if you are looking for a pai...

Your best bet there IMHO is the Nikon Aculon 8x42 porro, which has better build quality and a better warranty than the Celestron. Check the Nikon website, which regularly offers various models in factory refurbished condition. [The 8x40 Aculon is ~$70 there right now. There's also a 7x35 and a 10x50 if you prefer those sizes.

So: The Nikon Aculon should do fine if you're going to use these inside much of the time, where the differences in size, weight, and waterproofing don't matter much. It's one of the few recommendable bins at ~$100.

Monoculars are a PITA and don't save all that much on either cost or weight (fewer made, fewer sold, less economy of scale). At $100, your best bet is a decent basic porro like the Nikon Aculon 7x35 or 8x42. Stay with a major brand. The cheap ephemeral brands you'll see in online stores often get very little quality control.

It sounds like you have Nikon Aculon. I doubt there's any easy math for finding FOV at the long end because the zoom optics add complexity that will interact with FOV.