I can access the service menu on my Sony TV, and I'm ok with tweaking the geometry and position of the picture. But, I'd like to reduce the amount of overscan by reducing the vertical and horizontal size of the picture. However, given that the pre-set values of each are different, I don't know how to adjust each so that the picture stays in correct proportion. e.g. if I reduce both by a value of 3, I appear to be making circles appear as fat ovals. Even using Avia's overscan test signals don't seem to work, as the set doesn't appear to have a perfect 16:9 ratio. Therefore, if I reduce the overscan so that he 5% marker is just visible each way on the screen, familiar newscasters look like they've been squished horizontally. Is there any scientifically correct method for adjusting H-Size and V-Size, or should I just forget it and be happy with a centred image that has about 8% overscan?