> On 22 Aug 2022, at 22:28, silverdr_at_srebrnysen.com wrote: > > I am not sure what the OP meant with "drifty colours". SECAM was susceptible to (I am not sure how to name the effect) "irregular colour bleeding" ? Not like "ghosting" which follows the shape of the luma part but blurred/shifted but rather irregularly shaped colour distortions. Kind of colour noise following the actual shape. While I am not completely sure what the reason was, I might attribute it to something similar to FM noise, which might be caused by the fact that the chrominance was frequency modulated. When signal was clear and strong, SECAM looked as good if not better than PAL though, especially on older TVs where Hanover bars had to be "eye mixed" ;-) The problem was that getting that clear and strong signal was not an easy job What you’re referring to here is called “SECAM Fire”. There is a video playlist with lots of it if you search for that term on YouTube. The drifting of the FM carrier frequencies in the Procep SECAM encoder causes the entire R-Y and B-Y colour difference signal to become too positive or too negative. It’s most noticeable on black since the colour difference signals are supposed to be zero with black and any amount of spurious colour difference will show up as dark colours where there should be black. RichardReceived on 2022-08-23 01:00:08
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