Wrong Luminance Range on Output when using BMD Converters

[lukas-runge]

Hey Folks,

just putting this out here if anybody encounters the same issue:

I have been using Micro Converters HDMI to SDI from Blackmagic Design behind my Graphics Card to convert the signals to SDI for delivery to the in house projector and the live stream production folks.
Thus Resolume was actually saying that it outputs a 100% white output (checked in Advanced Ouput Panel) and I could confirm it by checking with a monitor directly behind the graphics card via HDMI I got a about 90% white signal behind the Blackmagic Converter which made my Key signal kinda useless... I know that this is probably a converter thing and already wrote Blackmagic Support about this. They informed me that I need to make sure to output YUV 4:2:2 instead of RGB from my NVIDIA graphics card. I checked all graphics driver settings to be on default and they were. Sadly the default in NVIDIA Settings seems to be RGB which then results in wrong conversion by the BMD Micro Converter. Changing it to YUV 4:2:2 in the NVIDIA Control Panel fixes it.

Thanks for the fast support from Zoltán and Blackmagic on my issue.
Kind regards
Lukas

[Zoltán]

Great to hear you found a solution Lukas!

[nmugnaini]

Cool thanks. Just tried it out, totally overlooked I was missing some power to my content

[Arvol]

A very big step everyone always seems to overlook is to actually look into your hardware. BMD products are crap! Do we all use them? Do I own about 50 of those converters... yes.

Inside the the micro converter hardware you can configure 2 options. No-one ever looks.
One of those options is a checkbox that asks: "Clip levels to legal limits".
This is essentially asking if you want the converters to hardcode a limited rgb range regardless of whatever the input colorspace is sending.

THIS, This is what is causing your content to look like crap. (and your LED walls to glow instead of going solid black)

If you turn that off, you can then use full range RGB without any issues.

Setting your computer color range to YUV like you mentioned is essentially loosing detail on the lower and upper end to fit everything into that limited colorspace. It'll work, but it's just a bandaid to real problem causing all of this mess in the first place.

I've had these boxes cause a lot of headache for some of my techs on shows in the past.

You'll need a micro usb cable and the latest converters software download from BMD to get into those boxes to change the option.

The other option deals with SDI type A or B, don't mess with that one unless you know what you're doing (for those using single or dual link sdi setups).

Hope this helps.