Is this a recognised problem and what is the cause (picture problem)

[paulr]

When you have a person with a multi coloured checked shirt on tv and the shirt causes that area of the picture to distort.

Sorry for a lack of technical language but if you've seen it you know what i mean. Its like either the signal or tv cant cope with all the information and it "shines" in that area of the picture.

What causes this?

 

[hornydragon]

its a "moire" pattern and happens when an area of fine detail intereferes with the pixel struture (or mask on CRT) of the display it down to a picture with smaller pixels than the dispays pixels?

have a search there are examples out there (i may not have understood your description though)

 

[JayCee]

When you have a person with a multi coloured checked shirt on tv and the shirt causes that area of the picture to distort.

It could be "Dot Crawl"...is your Sky digibox set to output PAL or RGB?

 

[Nick_UK]

It also happens with PAL signals when the frequency used to display the video pattern is quite close to the colour subcarrier frequency (i.e. 4.43 MHz).

 

[Chris Muriel]

Could also be sound/chroma patterning if viewing in PAL.

Chris Muriel, Manchester

 

[paulr]

This little video illustates the point.
On the edge of the E4 logo look at the shimmering.

http://video.google.co.uk/videoplay?docid=8796073281839948408

The first clip was on NTL cable,the second on freeview. The freeview one is much better (although its not that easy to tell).

 

[paulr]

It sounds like shimmering. Its most noticeable along edges.

(sorry if this is in the wrong forum,its on my NTL box,not sky)

 

[paulr]

I changed the aspect ratio to 16.9 on the output of the NTL box and its all gone. Why is that?

 

[JayCee]

I changed the aspect ratio to 16.9 on the output of the NTL box and its all gone. Why is that?

I don't know but if you have a widescreen TV it should be set at 16x9 anyway