How Sensitive is Sony's 4K a7s? Well, It Can Overexpose Total Darkness
The Sony a7s is an exciting camera for so many reasons: it shoots in 4K, is inexpensive, and compact, and has ISO settings ranging from 50 to 409,600, meaning that this little devil can essentially see in the dark, while still producing a relatively clean image. We've seen a few videos demonstrating just how sensitive the a7s is, and here's another one that shoes you that not only can you shoot in pitch black darkness, but you can actually overexpose it!
We've seen the footage testing the a7s' dynamic range, which is quite remarkable to say the least, considering the fact that a filmmaker can shoot by candlelight like Kubrick did in Barry Lyndon with a camera that costs less than $3000 (probably not with the same quality -- but we'll wait for the video that puts that shot to the test).
Speaking of quality, the images shot with very little illumination (a near-black room with little light) tend to get pretty noisy (understandably), so it's probably not the best idea to push this camera's sensitivity to the max for your narrative films if you don't have to. On the other hand, being able to set your ISO so incredibly high without completely losing your image is not only a feature that could one day save your shot (or help you find one), but it's the cornerstone of the camera's design.
In most cases, however, I can see a7s users enjoying the added advantage of being able to turn the ISO up a little in order to capture scenes they can only light with minimal lighting without losing too much clarity or fidelity. It's still impressive, though, that the a7s is powerful and sensitive enough to overexpose a near-black shot -- even though you probably don't want to overexpose your footage (it's just nice to know that the a7s is capable of letting you do it).
This video was uploaded by YouTube user Yoshihiro Enatsu:
As more a7s' find their way into the hands of creatives, we'll start seeing more and more impressive videos and films taking full advantage of the incredible dynamic range, which I for one can't wait to see. In case you didn't catch it the first time around, the camera will be made available in July for $2500. It's currently available to preorder on B&H and Amazon.