Sony's first mirrorless, full-frame cameras were designed to impress photographers. Now the Japanese company is going after videographers with a new variant of its 35mm, interchangeable lens camera, dubbed the A7s. For those who shoot video, the standout feature is that the A7s (unlike the A7 and A7r before it) can shoot full 4K video.

But there's another impressive improvement in the A7s: a maximum ISO of 409,600. That's the top end of its expanded sensitivity range, so it's safe to assume that results at that level will be a bit ratty, but it's an incredible number that matches Nikon's pro-level D4S. With sensitivity like that, the camera should be able to see in the dark (though focusing with such little light may be a problem). To achieve that kind of sensitivity, it's only natural that Sony would have to decrease the resolution of the full-frame sensor. The A7s has a resolution of 12.2 megapixels, compared to 24.3 and 36.4 in the A7 and A7r, respectively.

As you would expect, there are some other video-friendly features for pros on board. Shooters aren't limited to the AVCHD codec anymore — they can use XAVC S as well. Sony also makes a point to note that the A7s is the only full-frame digital camera that uses the entire width of the sensor when recording 4K video. That means that sensitivity improvements and shallower depth of field will be available to videographers as well as photographers. However, only 1080p or lower quality video can be recorded on-camera — 4K requires an external recording device connected via HDMI.

A full-frame mirrorless Sony made for videographers

Alongside the camera, Sony also announced at NAB in Las Vegas that it's working on a power zoom lens made for smooth adjustments in cinema applications. There's no pricing or availability information available for either the camera or the new lens, but expect it to come in north of the $1,699.99 asking price of the A7.

Correction: Sony's A7 mirrorless camera costs 1,699.99 (body only), not $1,999.99 as originally stated. The latter price is the cost with the kit lens.