Exactly You can see the options in the render globals window under resolution presets.There are four of the same kind (1 to 4k square) 1k being the 1024/1024 and 4k being 4096/4096.If you wand you can adjust the high and lenght so it doesnt have to be squared like the default ones.You can probably customize it if you want to make a 16:9 frame.