18% grey for PAL DVX colour bars

niknak

niknak

Well-known member
Barry or anyone techie minded. And i'll probably get shot down in flames for this but (deep breath) which bar in a set of SMPTE colour bars from a PAL dvx is 18% grey.
My logic is that I can calibrate my eyepiece with an 18% grey card and the bars from the DVX.
I have done a test and run the cams bars through FCP and near as I can tell the 4th bar from the left appears at 44 IRE on FCP scopes witch is close to 50% grey. Am I pissing in the wind here or is there some method to my madness.
Cheers.
 
I am not familiar with DVX, but typical SMPTE colorbars (not generally used in PAL) contain 75%amplitude @!100% saturation bars in the image upper part. The closest values to 50% (18% camera grey)are the green 44% and cyan with 53%.There are no exactly 50% luma values in color bars. B.t.w. why would you like to adjust the 50% level? Black level is much more important. In many cases colorbars in camcorders are not calibrated...
 
Thanks for the reply I was going a little crazy talking to myself. I am wondering if i can use the green or cyan bars to calibrate my eyepiece (which i have set to monochrome to check contrast more easily) by looking through the eyepiece and checking when bars are fed through the cam to see if a grey card matches with the 50% grey in the green or cyan bar to calibrate the eyepiece. Does that sound right. SO that the grey card and either the green or cyan bar looks the same as my grey card then i know that through my eyepiece is what im seeing accuratly. Am I on the right track here or way off.
 
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