Don't worry you can look for: width:1000 and height:1000 or any value you want. You can also search with > and < (let's say width:<1000
Or by megapixels: mpixels:>5000
Or by megapixels: mpixels:>5000
You can also try the wallpaper tag.
If wall paper are mostly what you are looking for like van said that'll be most useful to you.
iEnvy
sort/search pictures after size/resolution
would love to have an easy way of looking for wallpapers here, and the site seems to know all the resolution of the pictures anyways. (seen under the pics/in the bar too the left)
if there already is a way to do this, then i would be glad to know how since i have totally missed it and apologize for wasting your time.