Yes, easy in decent conditions. Obviously lighting and humidity/fog will compromise the best rangefinder, but Ive been able to range deer out well past 1000 yards, and you can range steel or reflective stuff a LOT farther than that. Even well past 1500 yards I’ve almost always been able to range the ground, a rock, tree, etc next to an animal even if I couldnt range the animal itself—Im not shooting critters out that far so close is good enough for me at those ranges.
“Seeing” deer is a meaningless metric though, no one can answer that question as posed. My uber-cheap diamondback HD’s that I consider pretty crappy can easily see deer at 1000 yards. The question is if the glass quality is good enough to pick up a tiny flicker of brown-on-brown movement at the edge of the field of view at 1000 yards, and then pick it out of the shadows to identify it as a deer with antlers against a broken background in poor light…they are not going to compete with swaros or similar. I have not personally felt handicapped by them, but I also dont spend days on end glassing for deer in the desert, etc. I use them for prs, my local deer hunting, and an occasional trip west to hunt elk, antelope, etc. For my use I have no complaints. If the above is what you are after, its probably not what you’ll end up being happiest with.