Hi All,

Below are 2 points that I have picked up from wwithin this forum

1) Most calibrators would say that 2.2 is the correct Gamma value
2) Black level adjustment using a PLUGE. Adjust the 2% below video black to be invisible and adjust the 2% above black video level to be JUST visible.

Now I’ve been trawling through technical documents from the EBU and the BBC. Their recommendation for studio production monitors are as follows:

1) Gamma should be 2.35 (As cathode driven CRT’s have a natural Gamma which equates to 2.4), for a dimly lit environment.
2) Black level adjustment using a PLUGE. Adjust the 2% below video black to be invisible and adjust the 2% above black video level to be CLEARLY visible.

Have we got different standards for America and Europe? Where did the points, which I see in the forums, originate from? They seem clearly not to be of European broadcast standards?

Some may say that you cannot see the difference between 2.2 and 2.4 Gamma settings. When I switch between the two, there is a very large difference within the picture content.

Thanks

1) it is unfortunate that many calibrators think 2.2 is the target gamma. It is not. 2.2 is the ENCODE gamma (and that's actually an obsolete gamma, current gamma is rec 709 gamma, which is similar). The end-to-end flow is not 1, but a bit greater than 1, about 1.25. The target display gamma is higher than 2.2, but is nowhere explicitly defined. It is inherently assumed to be a CRT's gamma, which is around 2.3-2.5ish in that range.

2) I am traveling now and so I don't have the documents in front of me, but I am fairly certain the standard method of aligning using pluge is to lower black level JUST until the below-black bar ceases to be visible.