Video Calibration

We are seeing more and more video walls being installed in the industry in all shapes and sizes. They are creating beautiful, huge displays for their users to get their messages out there. However, they are a little tricky to calibrate. You may say, “what’s the big deal?”

If an advertiser paid for screen time, and on one display their logo has a purple hue, and on an adjacent display it is green and sickly looking, it may be a big deal. You have a video conference going on the video wall, and a person’s face spans two displays where on the left they look like they just got back from a tropical beach (nice and tan) but on the right it looks like they are in a gas station bathroom (fluorescent lighting – blue). Participants will get lost in how he looks instead of what he’s saying, and the entire conference is wasted.

Apparently the industry standard is to balance video walls "by eye". Who's eye? The designer's, installer's or manufacturer's? What if the client doesn’t like what those eyes see? Where’s the number to confirm it works?” 

At one of our recent jobs, there were video walls made up of 360 video tiles. That’s a lot of balancing!
In order to keep everyone honest, we devised a color balancing verification tolerance. We sat down with the client with an unbalanced video wall and simply asked two questions:

1. What tiles look like they match?
2. What tiles look like they don’t match?

We put a number on both in terms of color temperature and brightness. We found that as long as the displays are within a certain degree range (color temperature) and a certain amount of nits (brightness), the tiles looked great.

We didn’t care whose eye was used to set up all 360 displays, only that the temperature and brightness needed to be within tolerance. The client was involved in creating the tolerance, so we were confident that the end result would be both verifiable for our test equipment and, most importantly, satisfactory for our client.

The funny thing is, by the end of the job, the installer was no longer balancing by eye.  It was so much quicker, easier, and better to put a number on it. They purchased the same colorimeter AVR used for the testing.

Next Case Study: Setting Gain Structure