I found out the aspect ratio that works: 3X2. 3 is width and 2 is height. So images like 600x400, 900x600, 1500x1000 will work fine.
I found out the aspect ratio that works: 3X2. 3 is width and 2 is height. So images like 600x400, 900x600, 1500x1000 will work fine.