Blu-ray versus DVDBack to advice guides
Blu-ray discs can deliver an HD picture that looks sharp, detailed and realistic, and breathe new life into old films. But not all Blu-rays are much better than the DVD. Find out which Blu-rays shine and are worth your money.
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Blu-ray discs are meant to be the only way to guarantee you get the best picture possible from your expensive, HD-ready or Full-HD television, offering true 1080p HD, uncompressed audio and even the 3D effect at home - but a Which? investigation has cast doubt on the high-definition claims made by some Blu-ray content.
However, even with the best DVDs and Blu-ray discs, you'll still want a Blu-ray player and TV that will do them justice. Which? tests more than 20 Blu-ray DVD players a year - try Which? for a £1 trial or log in to access our expert reviews and view the Best Buys that will make your favourite films look crystal clear and sound great.
How does Blu-ray compare to DVD in quality?
Blu-ray's high definition (HD) picture is made up of 1080 horizontal lines, compared to just 576 on a standard definition DVD. The extra resolution can make Blu-ray look sharper, more detailed and more realistic. Therefore, you'd expect the Blu-ray version of a film to be shown in a much higher quality - up to four times - that of the DVD.
Most new movies are released on both DVD and Blu-ray, and many older titles have been retrospectively launched on Blu-ray since the format appeared in 2006 - if you buy the Blu-ray version of a new movie released since then, you can be confident that the original material was optimised for transfer to Blu-ray. However, if you're keen to upgrade your old DVD collection with superior Blu-ray versions, caution is warranted.
Unfortunately, there's no way of telling which is best from the packaging alone. Most discs routinely promise a 'maximum high-def experience' but you may find that an '80s action movie on Blu-ray doesn't look much different to the DVD. Yet, irrespective of the quality, films cost more on Blu-ray than DVD (although prices have fallen steadily over recent years) - so we decided to test some classic titles for ourselves.
The result? The best Blu-ray films looked simply stunning and were significantly better than the DVD. And our tests show you don't need to spend a fortune on a Blu-ray player to enjoy the best Full-HD and DVD quality - find out which are the best cheap Blu-ray DVD players under £100.
Which? Blu-ray vs DVD disc quality test
Our expert viewing panel watched a selection of 17 films from a variety of studios, both made before and after the advent of the Blu-ray format, viewed on DVD and Blu-ray using two identical Sony Full-HD TVs and two identical Sony Blu-ray players.
The best Blu-ray films looked simply outstanding, but only five out of the 17 discs we watched were of the highest high-definition quality we were expecting and several proved disappointing. The results fell into one of three distinct groups: outstanding, a significant improvement, and marginally better or no difference.
Outstanding Blu-ray discs
These Blu-rays are significantly better than the DVD and offer the best Full-HD quality.
- Casino Royale
- From Russia with Love
- The Wizard of Oz
We found that newer-release films, Avatar (2010) and Casino Royale (2006) looked fantastic, and far superior to their DVD equivalents. Casino Royale was bursting with detail, depth and solid, bold colours. Avatar boasted, 'extraordinarily good detail and depth, that really does show HD off at its best', according to our viewing panel.
As both movies were produced after the launch of the Blu-ray format, the high-definition results came as no surprise. Yet this stunning standard was matched by a handful of old classics: Zulu (1963), From Russia with Love (1964) and The Wizard of Oz (1939) looked stunning, full of sparkle, detail and colour.
Movies showing a significant improvement on Blu-ray
For these titles, Blu-ray was significantly better than the DVD, but not outstanding. DVD quality was usually disappointing.
- The Matrix
- Terminator 2
However, none had the sparkle of the first group and the huge step-up was more to do with the disappointing quality of the DVD rather than exceptional Blu-ray quality. Grease (1976) on Blu-ray was a big improvement over the weak and insipid DVD version. Likewise, the extra detail of Gandhi (1984) on Blu-ray put the soft, low-resolution DVD version to shame. Terminator 2 (1991) and a particularly muted The Matrix (1999) were grainy on DVD, but solid and detailed on Blu-ray.
Marginal improvement or no difference
Here, Blu-ray was marginally better than DVD but not outstanding. In some cases it offers virtually no improvement.
- The Matrix Reloaded
- Die Hard
- North by Northwest
- Gangs of New York
- Master and Commander
- The Untouchables
- The Graduate
A significant proportion of the Blu-ray discs on test failed to offer a significant improvement over their DVD equivalents, even though they tended to look superior. In some cases this was thanks to the high-quality picture of the DVD itself. Master and Commander (2003) and The Untouchables (1987) Blu-ray discs looked superior but were only 'slightly sharper' and not deemed to be a 'significant improvement' or as good as the discs rated outstanding. The Matrix Reloaded (2003) looked great on DVD, but the Blu-ray offered 'no significant improvement' over the standard definition version. Likewise, Gangs of New York (2002) was good on DVD, but apart from having a slightly sharper image, looked very similar on Blu-ray.
"But the marginal step-up in quality wasn't always due to top-notch DVD performance.
Some Blu-rays failed to make an impression even when the DVD version was below-par."
Hitchcock classic North by Northwest (1959) on DVD was detailed, if a little flat, while colour on the Blu-ray version had been ramped up, but resolution didn't appear to have improved and some detail was actually 'crushed' by the deeper colours. Smeary, inaccurate colours and grainy picture noise made Die Hard (1988) on DVD look awful. Bolder colours and sharper, more natural images mean Blu-ray looks better, but only as good as a decent DVD and a long way off the best Blu-ray discs.
Ghostbusters (1984) sits at the bottom of the pile - the supernatural classic failed to impress on either DVD or Blu-ray. The DVD version was dull and lacked detail but the Blu-ray disc wasn't much better. Exaggerated colour and strong whites actually wiped out some detail (on the New York skyline for instance). The resolution wasn't much better than DVD and the level of grainy 'picture noise' was way too high for a HD disc. According to our experts, The Graduate (1967) 'doesn't offer any picture quality improvement over DVD'. Like Ghostbusters, the colour saturated the high-definition image and levels of detail were nowhere near the levels they should have been.
Which Blu-rays look best compared to DVD and why?
We asked the British Video Association (BVA, the body that represents the major studios in the UK) to shed some light on the differences, but they were tight lipped, instead insisting that research showed most consumers thought Blu-ray looked better than DVD. We don't dispute that Blu-ray generally looks better than DVD - in fact our findings support this - but simply saying 'it's better' doesn't explain the gulf in quality between a disc like Zulu at one end of the spectrum and Ghostbusters at the other.
We think that the likely explanation is that the movies have been converted from different sources of differing quality. The best are more likely to have been transferred from the original high-quality source (the negative), the worst merely copied and up-converted from subsequent standard definition copies of the original. If the source material isn't great, then chances are the final copy won't be much better despite the higher-quality format. And the more times you copy, the more the picture quality can suffer with each subsequent version.
Boosting the colour temperature and removing scratches can give a veneer of quality, but will pale next to a disc re-mastered from the original source. That's why 'Mastered in 4K' Blu-rays are appealing.
Although 4K (or Ultra HD) is relatively new to consumers, many films have been shot in 4K for years and the material of these discs has been derived from the 4K source and hasn't been subject to the same compression as DVDs and standard Blu-rays.
Find out which are the best 4K upscaling Blu-ray players to partner a new 4K TV.
Video: What else did our Blu-ray vs DVD test reveal?
There's no doubt that some Blu-rays look fantastic, but we found that some Blu-ray movies are almost identical in picture quality to standard DVDs. Our expert viewing panel watched each the 17 films simultaneously on Blu-ray disc and DVD, on two identical Full-HD TVs (Sony Bravia KDL-40W4500) and played back on two identical Blu-ray players (Sony BDP-S550). For the sake of comparison we left the 'up-scaling' option off - available when playing a DVD on a player connected to an HD TV via HDMI - so the DVD was watched in its standard 576p resolution setting.
Watch our video to find out more about what we found in our Blu-ray disc test.
How to find the best Blu-ray
Unfortunately, there's no way of picking the best based on the box cover. Generally, films and TV shows released since 2006 will look good on Blu-ray as the original material is likely to have been optimised for transfer to high-definition Blu-ray discs. However, caution is warranted if you intend to upgrade your old DVD collection to the Blu-ray versions. Studios may be more inclined to give label gems (like The Wizard of Oz) the full expensive re-master treatment, but an action movie from the 80s may not warrant such loving restoration when a more straightforward 'up-conversion' will do.
We recommend checking if the cover states whether the Blu-ray has been remastered (from the original source). Avid movie fans may be interested in 'Mastered in 4K' Blu-rays, whereby the disc material still has the same 1920x1080 resolution but has been derived from 4K sources, so it shouldn't have been subject to the same compression has standard Blu-rays, and therefore display better colour and detail. But those with a 4K upscaling Blu-ray player and a large Full-HD or 4K TV are likely to benefit most.
If you buy wisely your Blu-ray collection will look fantastic and for the large part the discs will normally look better than their DVD counterparts. However, the gulf in quality between the best and some of the rest is huge, and the marginal step-up in quality from DVD on many films makes it difficult to justify the extra cover price, especially if you're buying to upgrade your old DVD collection.