The digital TV service just launched by TelstraClear Ltd. in the New Zealand cities of Wellington, Kapiti and Christchurch will cost subscribers only about NZ$5 (US$3.49) a month more than the equivalent on the existing analogue service, the company says. For this subscribers will get higher definition ? particularly suitable for large plasma screens ? and a few extra pay-TV channels, such as UK TV and an Arts Channel.

Sound will now be in stereo, equipment permitting, of course, and an on-screen program guide will be available.

Upgrading from analog involves a new set-top box and an additional cable modem. Many customers of TelstraClear?s Saturn analog video will already be taking the company"s cable internet service. While it is technically possible to use the existing modem for digital TV, it is probably more convenient to set up a separate modem, says TelstraClear spokesman Ralph Little.

The improved resolution of digital TV shows to its best advantage on large plasma screens which are usually in widescreen (16 x 9) format. There are a variety of accommodations for customers who want to stick to their conventional TV, says product manager Jeff Doyle; they will probably lose some of the picture off the left and right edges, or have black strips top and bottom (?letterbox? format), but the loss is not major, he says.