Concerns are raised as soon as you get to the opening shot of Scorpio's sniper barrel against a blue sky; the amount of grain in the blue is really quite excessive, and the gun looks a touch soft. The situation then if anything gets worse with the sequence that follows, where Clint heads off to the site where Scorpio fired from. The picture continues to look noisy as he saunters along the street, and reaches its nadir once Clint is on the rooftop. What's more, there's also quite a bit of dirt and a few scoring marks to be seen as the credits continue to roll over the film. This is to be expected to some extent given the way titles were added to films in the period Dirty Harry was made, and some people reading this review might actually be happy to see such dirt, on purist grounds. But another take on it would be that the film hasn't been remastered with any great frame-by-frame care.

Thankfully this grubby opening isn't representative of the whole film. The sort of dirt on the print I described becomes much rarer once you get into the film proper; there are passages where the grain and dotting noise diminishes considerably; and better still, the picture sometimes actually looks sharp and 'HD'.

The famous scene where Harry buys his hotdog before taking out a gang of bank robbers, for instance, is certainly a vast improvement on the quality of the opening scene, with hardly any grain and oodles of sharpness and detail. Crucially this scene also shows a big improvement on any previous home entertainment release of the movie, including the DVD.

However, while the disc certainly has its good points, you seldom manage to get more than a few minutes at a time of the picture looking really good before it inexplicably deteriorates again.

A great example of this inconsistency in action can be seen in the police precinct, following the bank robber bust. Some of the shots here look really sharp and clean, others suffer with some slight motion blur, and still others - such as the one where Harry and his new partner first discuss why Harry is called Dirty Harry - look far grainier and rougher than the footage to either side. Go figure.

Colours are rather inconsistent too. The HD master comes into its own during the film's many really dark, night-time scenes, at which point the shading subtlety and flesh tone accuracy around is really pretty good. But during some brighter interiors skin tones can look distinctly orangey and dated.

Yet another issue I have with the transfer is that sometimes parts of the picture look slightly out of focus at their left and right or top and bottom edges. And as a last aggravation, some - though oddly not all - of Dirty Harry's extremely dark sequences suffer badly with the sort of overt grey dot crawl noise I've found all too common in Warner Blu-ray releases.

Some people might be feeling at this point that my expectations are a bit unreasonable given that Dirty Harry is, of course, now 37 years old. But you only have to look at the truly stunning job Paramount did in conjunction with Sky for the recent HD remasters of Zulu and The Italian Job to know that HD versions of old films really can look way better than the job Warners has done on Dirty Harry.

Now the bad news: perhaps inevitably, that remix only improves things to a certain extent. In fact, it might have been a better idea to leave the soundtrack mono - or at least have a mono option for purists to use.

The front soundstage is pretty reasonable. There's a definite sense of extra 'wideness', separation and clarity across your left, right and centre speakers; there's hardly a trace of the 'hiss' sometimes heard on vintage soundtracks; and vocals sound surprisingly realistic rather than sounding artificially 'separate' and thin as can happen when old vocals are pulled out of a mono mix to go into the centre channel of a surround mix.

Lalo Schifrin's superb score bursts into life nicely across the front soundstage too, with CD levels of clarity and a really decent dynamic range.

Vocals occasionally sound a touch muffled, especially when the score is in play, but overall the front soundstage really is a decent effort.

Just don't expect much from the rear channel. There's a very low-level attempt to put some elements of the score into the rear channels, but you generally have to strain your ears to hear them. And there are precious few signs of any effects being transported into the surround mix. Examples where this does happen, such as when the helicopter circles around your AV room as Harry sets up his rooftop surveillance system, really stand out, making you all the more aware of how little the rear channels are used in general.

Probably the best thing that can be said about the audio mix is that Harry's gun sounds significantly louder than those of anyone else in the film, reaffirming the classic claim that it is, indeed, the most powerful handgun in the world.

Admittedly some of these features are of better quality than others, but when they're good, they're brilliant. Here's the full list.

1. Commentary by Historian/Eastwood biographer Richard Schickel
2. New retrospective documentary The Long Shadow Of Dirty Harry
3. American Masters profile: Clint Eastwood: Out of the Shadows
4. Vintage Profile: Clint Eastwood: The Man From Malpaso
5. Interview gallery
6. 2 vintage featurettes: 1971's Dirty Harry's Way and 2001's Dirty Harry: The Original
7. Dirty Harry Movies Trailer Gallery

For a review of every feature on the disc, click here.

The pop up menus are very basic, graphics-free zones too, with the only even slight sign of imagination being the way the illustrative images for the different chapters you can skip to appear in the crosshairs of a sniper's rifle..