Spears & Munsil Blu-ray Test Disc

[HDTV1080P]

Originally Posted by 145gtw

For those unaware, the UHD Edition is now available.

The official thread for this 4K Ultra HD Blu-ray disc is located at the following link


https://forum.blu-ray.com/showthread.php?t=318227

[rickardl]

Originally Posted by Stacey Spears

Turn contrast up until the highest bar you have clips and bring it back down one clip. Make sure that this does not cause RGB squares on the clipping pattern to clip. That will be the highest you can set contrast.

Next, Look at the gradient/ramp in the middle of the contrast pattern. Turn it down, from the top point you found and see if you can find the position where it is the smoothest. Sometimes its at the highest point, sometimes a few clicks below.

I am restarting this old thread about the HD benchmark disc...
In the past, I have been looking at the bars with numbers on this pattern
http://spearsandmunsil.com/wp-conten...Contrast_Y.png
and I have been able to see the 253 bar against the 254 white background with the Contrast setting up to about 95 (out of 100) and even higher on my Samsung Plasma.
But I noticed blooming on lamps, clouds and very visible film grain, especially on skies on black and white movies and I have therefore reduced the Contrast setting by visually looking at real content in movies.
The Contrast setting then ended up around 85 instead.
I don't recall why, but I recently looked at the ramp instead and read the help text

The ramp in the center that goes from black to white and back should have a very thin white stripe in the center, but no other streaks or bands.

and started adjusting the Contrast down.
The "stripe" in the middle should be really thin, right? Almost not visible as a stripe but rather a smooth continuous ramp since the middle section here

,between the upper and lower 242 bar, is actually going from left 242 up to 254 and down to 242 again to the right side.
With a smooth continuous ramp and basically no stripe in the middle, I end up with a Contrast setting of 72.
Here is a blow-up of the middle section:

This might be just how my plasma behaves but I get a really good picture with no blooming at all and film grain that were very visible and "intrusive" before, now look more like fine velvet.
The downside is that the picture is darker.

The odd thing is that using the bars vs the ramp gave completely different Contrast settings, I wonder if that is common or if it just my plasma that is "odd".

[Stacey Spears]

The ramp in the middle goes from 1-254-1. So close to the center might look like:

250, 250, 250, 251, 251, 251, 252, 252, 252, 253, 253, 253, 254, 253, 253, 253, 252, 252, 252, 251, 251, 251, 250, 250, 250.

I don't recall home many times each code value is repeated on the gradient, but the center value of 254 is only used one time.

If turning contrast down reduces the bloom, then I would stick with that.

The stripe down the center will be distinct similar to the image you posted with the rectangle.

The ramp and the bars use the same values, just different ways to view the same thing. As it starts to clip, that center line on the ramp will get wider and wider.