Click on image to enlarge (Courtesy of DCfever).
The Chinese site DCfever posted the first real Sony A7s High ISO test. Please remember that firmware of the camera is 0.01 only! And these are Jpegs too (as usual RAW will show a better performance). At first glance all I can say is that up to ISO 25,600 images do look pretty good. Real huge deterioration happens only from 102.400 ISO towards.
Again, I repeat: The A7s images with final firmware will look even better! And if you buy the new [shoplink 26501 ebay]Mitakon 50mm f/0.95 on eBay (Click here)[/shoplink] you will be able to shoot ghost at night too :)
Reminder: You will need the Atomos Shogun at BHphoto (Click here) to grab 8bit 4:2:2 4K video.