Australia's newest television channel shows 24 hour sport in high-def, but it comes at the expense of other high-def programming.

Network Ten became Australia's first commercial network to take the next digital leap this week, converting Ten HD into One HD - a 24 hour high-def sports channel. Ten has also launched a second standard-def channel called One, which is a constant simulcast of One HD. Of course you've still got the main channel, Ten, which gives Network Ten three digital channels in total; Ten, One and One HD.

One HD is obviously a smart move by Network Ten considering Aussies' passion for sport, but it comes at a price. Previously Ten and Ten HD were mostly in simulcast, so high profile sports such as AFL were already shown in high-def. It also meant that many of Ten's popular sci-fi and drama programs were shown both on Ten and on Ten HD in high-def. Late in the evenings, Ten HD would break away from the main channel to screen re-runs of sci-fi classics such as The X-Files and Buffy.

When Network Ten announced plans to convert Ten HD into One HD, sci-fi fans were hoping that the network's new second SD channel would come to the rescue by screening alternative programming to Ten - similar to the relationship between ABC1 and ABC2. Instead the second SD channel, One, is just more sport. The exact same sport. When the AFL is screening on Ten, the same game will also be on One HD and thus on One as well. So all three of Ten's digital channels will be screening the exact same thing. So much for more choice.

Viewers have lost the alternative late-night content that was on Ten HD, plus they'll never see any of Ten's sci-fi or drama in high-def because the HD channel is all sport, all the time. If you've spent good money on high-def gear, you're entitled to be annoyed. You'd also be tempted to turn to Blu-ray or BitTorrent to watch the latest sci-fi in high-def.

I think Network Ten should have struck a compromise by making the second SD channel a 24 hour sports channel. Then the high-def channel could screen a mix of programs from Ten and the sports channel - letting viewers see both high-def footy and high-def sci-fi. It will be interesting to see the public response to One HD and I'm sure the other commercial networks will watch it closely before unveiling their own plans for extra channels.