Spotting a battle a mile away?

[enrious]

Yes if clear weather, you can see a skirmish at 1 mile(1650yrds).
Making out what each combatant is, not so much.
Marines train open sight to hit man-sized targets at 500yds. Trust me the target looks small.

Actually, it's 500m, roughly 550 yards.

So picture that flag at half-height/size. Actually, knock a foot off it first, as from what I can tell, golf flag sticks are usually 7' (we all know the Internet doesn't lie and I don't play golf...). Knock another half foot off if you're basing a human being on the average height of 5'6" rather than 6'.

Now picture it slightly moving, maybe there's wind blowing, dust in the air, the glint from the sun. You can easily tell there's movement, but telling what it is that's moving is another thing. You could probably use contextual clues to help tell what it is, but if you think it's people, good luck telling who's who - or what the movement is all about.

That's for 1000m, 1100 yards.

Of course, again context can help. A lot of movement around a cart could be simply that the cart broke an axle, a problem with one of the pulling beasts, or maybe they're getting ambushed.

And for a mile away...that flag is what, roughly 1/3 as big as what you see in the picture?

EDIT: And btw, how big is that flag in relation to a human head?