@dsg: HD channels will have black bars on either side of the screen when displaying upscaled SD (4:3) content. Black bars will also appear at the top and bottom of the screen when you watch movies that have aspect ratios different from your TV (typically, this is truer of older movies). Sadly there's not a lot that can be done about this, as the image ends up warped and stretched. Apologies for any inconvenience this may cause you.
@dsg: If the option isn't available on the TV to change the Picture Size Settings, and you have an external device connected such as a cable or satellite box, then you could try checking the external device settings to see if the aspect can be adjusted. If not, are you able to confirm if the problem is present for all content, old and new?
@dsg: If you're mainly viewing content via applications then I recommend checking the app settings themselves for aspect options. You should find that if you tune the TV to freeview/terrestrial channels, or connect an external device, the Picture Size Settings will be available to you, however as standard you will find that older media has horizontal or vertical black bars on all platforms.
@dsg: It does appear to be that way. I had a look on one of our TV's in the office that's in demo mode, and the Picture Size Settings were greyed out. In the picture size settings in the user manual it states "Adjust the picture size options on your external device or set the TV to full screen," which seems to suggest that the option is only applicable via certain sources. Apps will automatically set the aspect ratio based on the format of the content being viewed, so the TV won't allow you to manually adjust it via the internal settings.
