[Bizman]

I have a Bush 16:9 analogue crt TV with the aspect ratio set to Auto-detect mode. In addition, I have two set-top boxes connected via SCART leads via a DVD-R and a VCR.
What I am interested in is a better understanding of the criteria for the aspect ratio to be Auto-detected.
Presumably it is sent with the picture, or is it calculated from the horizontal & vertical timings? Why do I sometimes get different aspect ratios on analogue and digital versions of the same channel, or differences when recording and playing back ? Should the set-top boxes be set to RGB or Composite? Is it a SCART issue ? Any technical contributions welcome.

[blu]

Please anyone correct me if I'm wrong, but maybe I can answere a couple of your Q.

"Why do I sometimes get different aspect ratios on analogue and digital versions of the same channel"

The Digital BBC ITV channels etc broadcast in 16:9 whilst the analogue broadcast is a chopped down version of 14:9

Re the Auto change of the screen ratios.
All digital channels broadcast a signal that tells your telly what ratio to use so long as you have your telly set to AUTO that is.
Of the analogue channels only CH4 broadcast this signal.
So analogue channels (except CH4) will switch to whatever your 4:3 Auto Aspect setting is set to.

blu

[Bizman]

Thanks Blu,

So on those channels that do broadcast the aspect ratio, should I have the set-top boxes set to RGB or composite, or does it not matter?

Would the information be lost on recording and subsequent playback?