Sony A7s Guide

Usable ISO Range for night shooting

In this lesson let’s study footage for both S-Log2 and Rec. 709 for low light ability.


For S-Log2, I recommend the following ISOs:

  • 3200 (preferable 100% of the time)
  • 6400
  • 12800

Anything above this range seems to have problems. Here are some screenshots (click to enlarge, JPEGs actual size):

25KSlog2 50KSlog2 100KSlog2 400KSlog2

Notes on the scene: There is almost zero light in the foreground trees, it’s even hard for the eye to see. The background has some light due to houses nearby. This is as extreme a test as you’d ever see. Only thing worse than this is shooting with the lens caps on!

25,600 ISO might seem like it’s okay, but when you add camera movement to the footage, there is a definite loss in resolution and obvious artifacts. There is also a major loss in dynamic range by this point. If you’re desperate, you can make it work, as is also the case with 51,200 ISO. Anything over this is unusable for a professional production, in my opinion.

Rec. 709

How does the camera perform in Rec. 709? Here are some screenshots (click to enlarge, JPEGs actual size):

50KRec709 100KRec709 200KRec709 400KRec709

Notes: Picture profiles turned off, Neutral style. Same scene as above.

You might feel it does better than it does in S-Log2 (because of low light noise reduction that happens in camera, even if you turn it off in the menu), but that’s not true. You can grade the S-Log2 footage better by crushing the blacks and eliminating the ugly color noise easily. But try grading the Rec. 709 footage!

Therefore, if you need to shoot low light footage, and would like to control the final image, stick to S-Log2, between ISO 3200 and 12,800 for highest results, and occasionally go to 25,600 and 51,200 only when desperate.

Note: If you’re worried about the red splotches around the image at high ISO, do not be worried! This is perfectly natural.  There’s so less light in the corners that nothing but noise shows up – this is mostly due to the lenses and natural vignetting that occurs around edges.

Click on the link below to the next lesson or head over to the main menu (above). If you need help with something, feel free to send me an email. I’ll try to get back to you as soon as possible.