A significant difference of all these Hi-Vision LD players (which are, incidentally, just that, with no provision for CD replay, is this the end of the combi concept?), is that instead of the conventional 780 nanometre laser they make use of a shorter wavelength 670nm device, able to read the more closely packed spiral of pits on the new discs. With NTSC the nominal track pitch is 1.67 microns (though can be less) whereas with Hi Vision it comes clown to 1.1 microns. The actual size of the pits encoded on die discs is the same as before. However, in CAV and at the fastest CLV speed the new discs rotate 50% faster at 2,700 rpm (NTSC is 1800rpm.) Though the shorter wavelength laser is a necessity for Hi-Vision to cope with increased bandwidth, it will be interesting to see how this affects replay of NTSC discs. In theory, the performance should improve.