How to expose correctly using the Atomos Shogun – S-Log2 4K

In this lesson we’ll learn how to expose S-Log2 in UHD using the Atomos Shogun.

The test is similar to what I used to explain the Picture profile modes, and I’ll be using a DSC Labs OneShot as reference. The lighting is pure halogen, custom white balanced at 2900K. The light is from the left that is why there is a small but negligible fall-off (the real world barely has zero fall-off).

The spot meter in the camera was measured within the large grey patch for exposure. Exposure settings are available in the first image.

Here are the results (click to enlarge):



  • Look at the waveforms and vectorscope closely. You’ll see that the image in UHD has more ‘busy-ness’ than those found in 1080p S-Log2 (previous lesson – study the two side by side). Does this mean the uncompressed HDMI version has more information? We’ll look at this later in another lesson.
  • Everything else is similar to what we’ve seen earlier.

How to expose for S-Log2 UHD using the Atomos Shogun

It’s exactly the same as S-Log2 in 1080p:

  1. Use the wolfcrow system.
  2. Keep middle-grey at about 70 IRE and use 105 IRE to check for blown highlights. Use the waveform and/or zebra for this.
  3. Make sure the RGB parade lines up – this is a quick indicator of white balance issues. Forget the vectorscope.
  4. If using the false color, middle grey should be at ‘lightest grey’, and really dark skin should not fall below green. Avoid using the false color tool as a reference.

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.