S&M Clipping Test Pattern Levels

Does anyone have information regarding the RGB (count) levels of the 4 clipping boxes for the S&M Clipping Pattern?

It has the White/Red/Green/Blue dual nested boxes. What is the difference between the left and right halves for each color? Are they all supposed to be visible? Or is a subset sufficient?

A nice B/W outline picture with numbers would be nice. I'm surprised that S&M doesn't have it in the Help on their disc on in the print documention.

I’m not sure if you’re familiar with the old US TV series “Raymond”, but in the words of Frank “Holy Crap!” Your response is excellent! I thought someone might have had the same question about that Test Pattern, but you took the thought about 87 times farther than I was thinking. I hope Spears & Munsil (as well as other test disc people) take note about complete documentation. Thank you! Or σας ευχαριστώ.

The reason I asked this question is that I have been trying to diagnose some color problems with my Sony BDP-s390 player and a Panasonic 42PZ85 and Westinghouse VR-3730 HDTVs. I originally noticed poor chroma alignment with the YCC=4:2:2 color output to the Panasonic plasma TV. Basically, following S&M suggestions for performance evaluation I found that the RGB color output to my TVs improved chroma alignment and gave me the best Chroma Burst and Chroma Zone Plate Test Pattern results. I improved the picture quality of both TVs or so I thought.

While doing research for this problem I came across Chris’s (http://www.avsforum.com/avs-vb/showt...3#post22012693) work on a problem with the Sony S390 RGB output exaggerating GREEN output and clipping my TVs. So, I needed to look for color clipping levels in YCC=4:2:2 and RGB outputs for my displays. The S&M clipping display indicated a problem but I could not interpret the results without knowing the levels in the squares being show.

BTW, I noticed in the Right square the outer to inner squares go from 239, 254,244,251,247,239. Is the 244 square correct? It starts decreasing then increases for the single square then decreases toward the center low of 239. The count order looks funny (not monotonic)?

NOTE: This Chart was corrected by ConnecTEDDD in this thread below.

Thanks, again for the clipping diagram correction and update. I checked this pattern again this morning. Your latest data seems to be right. I only can observe the relative brightness of the squares on my display. This information really should have been in the S&M documentation somewhere.

I was wondering how you measured the S&M Clipping pattern. Pretty slick how you used the VideoEQ box and dropped the squares level until you found the equivalent interperlated value for the disc. That must have been tedious!


That little VideoEQ box would be nice, but for right now I just have my basic TV controls to fix (or not) any problems. Maybe some day!

Thanks, again.

This post really should be saved as a sticky. It's an excellent reference to what a complete set of HDTV test patterns should look like. It can give all the DIYers an example of how a test pattern disc should be. Maybe someone can even come up with something that Ted doesn't already have? Or not! Bravo, Ted!