The TRUTH: High Megapixels + BIG Prints are a WASTE? iPhone vs Sony a7R IV vs Sony a7 III

There's an old saying that you need "300 pixels per inch" to make a good looking print. That's NONSENSE! But how many megapixels do you REALLY need to make great looking prints? We used 3 different cameras (iPhone X, Sony a7 III, Sony a7R IV) at 4 different megapixels (12 megapixels, 24 megapixels, 60 megapixels, 240 megapixels) and printed them at 4 different sizes (8x10" 16x20", 32x40", 64x80"). Then, we put the images in front of a diverse group of people: professional photographers, amateur photographers, and non-photographers... young and old, to see which combinations they felt were acceptable and whether the high megapixel images really produced visibly sharper results.

Stunning Digital Photography (the #1 photography book in the world):