Friday, January 15, 2016

Sony FS5 Highlight Fringing Artifacts

The video production company I work for just purchased a Sony FS5 as a companion to their venerable FS700. It is perfect for our needs as it is lighter, more ergonomic, matches the look of the FS700 in 2-camera productions, and allows us to move into 4k production. 

There are a lot of little things on the FS5 that add up to a great little camera. But there are also a few things that can drive you crazy. The strange artifacts in UHD recordings at 3200 ISO and above have been well-documented. But another annoying phenomenon has yet to be mentioned on the interwebs: highlight fringing artifacts in 1080p. In the Sony FS5, ugly fringing artifacts appear where bright highlights meet dark areas. In the frame grab below, notice the ugly maroon aliasing lines on the statuette's legs.

This only happens in 1080p recording, and looks worst in the SLOG gammas.
The artifacts appear in internal recording, as well as on external recorders like the Atomos Shogun. SDI and HDMI
outputs both exhibit the problem. These artifacts do not appear in UHD recording.

These shots were recorded to an Atomos Shogun via HDMI.
If you have an external recorder and need 1080p output that avoids this fringing issue, a solution is to set the FS5 recording to UHD, but set its HDMI output to 1080p. That feeds a 1080p signal to the Shogun. But I am pretty sure the output is only 8-bit instead of 10-bit. I hope Sony can address this problem so that users can utilize SLOG2 and SLOG3 in full 10-bit 1080p without getting these ugly highlight artifacts.