Low-light shootout: Nikon D4S vs. Sony A7S

Low-light shootout: Nikon D4S vs. Sony A7S

In recent years, high ISO capabilities have moved to the forefront of many photographic discussions, and we're even seeing some companies release cameras with a lower mega-pixel count in favor of higher ISO sensitivity. The Nikon D4S and Sony A7S are two prime examples of this, with both able to go up to an unprecedented ISO 409,600. But exactly how usable are these crazy ISO levels? We put the cameras to the test to find out.