A key IT player, Hewlett-Packard has been ramping up its presence in the projector market in a major way. HP customers are more likely to be showing PowerPoints than Harry Potter movies, so data projectors have always been their first concern.

Nevertheless, HP has decided to make a parallel range of data and home theatre projectors. The obvious question is this: what law says that you cannot use a data projector for home cinema, especially as they both use similar technologies, and have similar facilities under the skin?

Let's look at the vp6321, which is first and foremost a data projector, and see. It is just about everything you expect of a good, but relatively affordable, home cinema projector, even though it is not billed as one, plus it has some extra advantages that come from its data heritage. It is very compact, and includes a carrying handle. It is impressively, almost unfeasibly bright at 2,000 Lumens.

The DMD that HP has chosen, however, definitely shows its data heritage. Its native resolution is identical to most Windows computers at their normal desktop resolution without requiring scaling - 1024 x 768 pixels. This is a respectable resolution for home cinema too, but it is natively 4:3, and to achieve 16:9 requires grey guard bands above and below the picture.

But even 16:9 displays share the same problems when they're asked to reproduce more extreme cinema-like aspect ratios, 1.85:1 or 2.35:1 (Cinemascope), for example, which still need to be letterboxed in a 16:9 display area. Actually the grey above and below the screen is not too grey in this case, as the vp6321 has a very respectable 2500:1 contrast ratio, and impressively inky blacks. It remains a disadvantage, but it may not be a deal breaker in practice.

And so it continues. The vp6321 has a decent range of socketry, including an encrypted DVI-HDCP input, which is the basic requirement for accepting a digital feed from a DVD player with a DVI or HDMI output. And it does have the wherewithal through the menu system to change its spots to suit the application, though there's neither the subtlety nor depth of adjustment available to rival more practiced home cinema operators.

You also get the ability to customise the picture modes using all the available menu settings for particular purposes, and call them up with a single button press. Oh, and cost of ownership is unusually low, as HP's claimed lamp lifetime (8,000/4,000 hours depending on mode) is the best in its class.

In the end, it's almost too easy to make a really compelling case for the vp6321. Just consider. It is extremely bright and has excellent midrange contrast, and respectable black levels too. As a result it looks bold and punchy, which is very attractive on first acquaintance. It even has video processing of sorts (using TI's in-house ARM powered solution) to sort out scaling and deinterlacing.

Performance

Although primitive by home cinema standards (Faroudja processing is the benchmark here) the vp6321 is nevertheless better than some data projectors we have examined. Those projectors to hand with Faroudja processing onboard delay the video signal by a significant fraction of a second longer than the HP (tested by using a splitscreen presentation using parallel S-video outputs from the same Pioneer DVD player). This very roughly indicates the amount of extra work other projectors are doing to the signal compared to the HP.

If you look more closely, there are other limitations to the vp6321, though on the whole they're often surprisingly subtle. One of the consequences of primitive video processing is a significant amount of video noise, and blocky motion artefacts. These effects were noticed, among other places, in some of the action scenes of Pirates of the Caribbean, which looked decidedly messy. Video noise wasn't the only offender here. The cooling system is by no means quiet, though the character of the noise is relatively smooth and innocuous.

Colour reproduction was another area where the HP is less than first class. It lacks the subtlety that a top-class projector brings to the party. You can see this, for example, in the lack of delicacy with which it handles skin tones (try some of the early scenes from Chicago).

Despite the good contrast ratio, there was clear evidence of compression in the near blacks, which tended to merge together, especially if the middle tones and the highlight gamma settings were anything like correct.

Even in well-darkened surroundings, the vp6321 lacked the almost tangible walk-in quality that distinguishes the best from the rest. Where the HP excels is paradoxically where a full blackout cannot be achieved. Perhaps this is not so paradoxical after all.

This projector shouldn't be a good bet for home cinema, but in the end it's really not bad. Picture quality has plenty of what might be described as punch and dynamics, and its handling of motion artefacts, though well below home cinema norms, is not completely unacceptable at the price. Resolution is good even allowing for masking down the XGA resolution DMD.

It's two best features, however, are its prodigiously bright output, which means you can get away with a room with a degree of ambient lighting, and the extraordinary long (claimed) lamp lifetime. Alvin Gold