For anyone calibrating multi-camera setups, the DSC labs charts are the industry standard for camera calibration. They are SMPTE colour accurate and used by camera manufacturers along with broadcasters making camera matching quick. The chart colours are printed at half-saturation values to maintain accuracy on camera in the printing process. However, to view them accurately on the vectorscope requires the vectorscope to have a 2 X Gain setting which essentially magnifies the vectorscope signal display in the vectorscope by 2 X without affecting the actual video chroma signal. The refeence boxes on the vectorscope stay in their same reference positions. This means when using the Vmix calibration tools you only need to adjust until the Chart colours fall into the boxes on the vectorscope including the skin tone colours to fall on the skin tone line. When matching cameras if they all have the DSC colours falling in the vectorscope boxes then they will match under the various lighting conditions you lineup your cameras under. It is a quick, easy and accurate way to match the chroma values of different cameras.

I have included a sample of the current V Mix vectorscope without the 2 X gain feature and the DSC chart to show how the rec 709 colour values are displayed less than hitting the boxes due to not having 2 X gain feature. As a note, the DSC chart example used also has rec 2020 colours in it so it would also be good to have the 2 X gain feature for those doing 4K rec 2020 camera matching since you could get accurate colours in 4K. Since this feature would not affect the actual video chroma signal and only be part of the vectorscope display, having it selectable would be a great benefit to accurate camera balancing in V Mix. I hope this feature could be part of V Mix as it would make camera calibration so much easier and accurate.

Vmix Vectorscope dsc chart.jpg (254kb) downloaded 0 time(s).

This is what 2 X gain setting would look like, so only the signal doubles in size with the reference box points for colour etc remain in the same place without affecting the original video signal itself.

Slide2.JPG (113kb) downloaded 0 time(s).

This means when two video signals that have the DSC labs chart in them for reference if the chroma is adjusted for those video signals, such as multiple cameras, so the colours fall into their associated colour squares in the vectorscope you will have matched cameras for colour.