CompuServe Messages

NTSC Limits

    14-Sep-95 09:58:26
Sb: #122442-NTSC Limits
Fm: michael mcbride 76601,2354
To: Wayne Cole 76370,621
Wayne, <<Well, yes and no.>> PMFJI, but I wanted to thank you for writing in such detail about this subject. I've attempted to understand the relationship between the primary colors so my graqhics won't be too hot, but it's so confusing. Your help is greatly appreciated! I have two (2) questions. 1. If one doesn't have a WF monitor is there a formula to determine when a color is too hot? 2. My biggest problems come when the background image in CG or the backdrop image in LW is too hot. How do I reduce the chroma/luma on backdrop images? Example: Right now I'm working on a series of CG pages. I've seen to it (partly thanks to your comments here), that the color values of all the fonts and graphic elements are below 100 ire on my WF montitor. But, my background, which is a still shot of black draping with jewelry, is at nearly 110 ire (actually it's the jewerly in the shot that is so hot). Short of running this image through, say ImageFX to reduce the signal, is there a way to do this in the Toaster? Oh, and another thing I've been meaning to ask you concerns the Toaster's output. I send NTSC colorbars, from my Grass Valley sync/color bar generator to my Sony monitors and Leader WF/Vectorscopes for recalibrating. Once everything is set and on the proper marks I send the colorbars the Toaster itself generates. When I do this the WF readout drops about 5 ire, and all the vectorscope readings drop out of the RGB boxs slightly. The luma stays where it is. Just the chroma moves. Why? Is this normal for the Toaster, or is my board in need of repair? I can bring the vectorscope marks back into their boxes with the Gain knob. Is this advisable, or necessary? Thanks again for all this free info. I think this would make an excellent, and useful article. Based on the number of responses in this forum to this thread, I'd say I'm not the only person that's perplexed by colors that run to hot for NTSC. Take care, Michael,CyberGrafx.3D