Hi! I am new to colourspace and monitor calibrating. I've been watching all the videos I can find and am getting the hang of colourspace. I am trying to calibrate my smallhd 703 and am unsure at what level I should set the backlight?

This article seems to indicate Studio/709 but this one seems to indicate 100% backlight.

Anyone have any ideas? Thanks in advance!

Each calibration is valid for specific backlight settings.

If you are a purist, create two profilings, one for backlight 100 (for DAY) and a different (for Night) with ~100 nits peak.

The backlight is used to set the peak brightness.
For for a grading application you would aim for 100 nits peak when calibrated.
For on-set use, where the environment is not controlled as in a grading suite, you will need the display peak to be brighter.

See: https://www.lightillusion.com/viewing_environment.html

Steve