Ran into this little problem when setting up a new AV receiver with HDMI inputs and outputs. I have all my video going into my Onkyo TX-NR808 and using that for switching between video devices (Mac mini, PS3, BD player etc.), so I need all the devices to output HDMI video levels (16-235) instead of computer levels (0-255). If the video levels aren’t the same the TV (as it’s calibrated) will crush blacks below 16 and clip whites above 235. Normally you can change the HDMI level on each HDMI input on the TV, but as I’m using just one input (because of the AV receiver) that is not a solution.

Only problem is – there is no way of changing the output levels to video levels in OS X. After a lot of searching I stumbled upon Black Light which solves the problem.

Black Light preferences

Since I’m doing a lot of switching between Plex and EyeTV this sometimes resets the changes that Black Light makes to the output. This can be solved be making Black Light continuously re-apply it’s filters (so remember to check the “Continuously reapply effecy”). However as it resets contrast/brightness every few seconds Plex will now be unable to fade down when pausing a movie (or using the screen saver).

Download Black Light from here: http://michelf.com/projects/black-light/

At first I had my reservations about using Black Light as I suspected that it would cause colour banding, but after running a few tests it’s visually the same as running 0-255 (with the TV adjusted to receiving 0-255).