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Name                Ravi Manoharan, via e-mail (*)                      

Kit                    Thinking of buying a video projector

Problem            What are the fundamental differences between the various types of video projector, Ravi asks? Whilst he's on the subject he's also curious about screen sizes, when the specs quote a maximum size of 500-inches are they serious, if not, what would be the recommended size?


Expert Reply      There are basically three types of video projector. Until recently most models used high intensity CRTs, which are basically small and extra bright picture tubes, similar to the type used in normal direct view TV. In a projector there are three of them, beaming red, green and blue images through a series of lenses onto the screen. CRT projectors produce a clear sharp picture but the tubes age. After several years' hard work light output falls and eventually the tubes would need replacing, this can be expensive. Some CRT projectors also require occasional adjustment but in general they are very reliable, fairly quiet – they have a cooling fan -- and comparatively inexpensive.


The second type uses LCD panels, similar to the little screens used in pocket TVs and camcorders. There are two types of LCD projector, cheaper models use a single LCD element, and dearer models have three, one for each primary colour. The LCDs sit between a powerful lamp and a lens system, it's a bit like a slide projector. Triple element projectors produce the best picture quality, single element models tend to throw up a fairly coarse image, it's a bit like looking at a TV picture through a fine mesh. The LCD elements don't wear out but the projector lamps have a finite life and some cost a couple of hundred pounds to replace.


The most recent arrival is the MMD (micromirror device) or DLP (digital light processing) type projector. These use a microchip encrusted with thousands of microscopic mirrors that can be electronically tilted, forming a picture display matrix so each micromirror is effectively a single pixel. The picture is created by shining a bright light onto the surface of the mirror, and beaming the reflection through a lens system and onto the screen. In order to create a colour image the image is split into its three colour elements, which are fed to the MMD chip in rapid succession. A spinning wheel with three colour filters is interposed between the light source and the chip and synchronised to the colour information on the chip. In that way separate red, green and blue images are projected in rapid succession and these are combined in the viewer's eye – thanks to an effect called persistence of vision -- to create a colour picture. Picture quality on the models we've seen is very good indeed. DLP projectors tend to be quite compact for a given light output. Like LCD projectors the lamps have a finite life and can be quite expensive, and they the colour wheel motor makes a distinctive whine.


Maximum screen sizes are always a bit optimistic and are usually only possible in complete darkness, the spec sheets supplied by most manufacturers give specific recommendations about screen size based on the prevailing lighting conditions, so    

Ravi is going to have to do a bit of homework






Name                J.Christie-Brown, via email                           

Kit                    Nokia Sat-1700 satellite receiver

Problem            The viewing card reader in J. Christie-Brown's Nokia satellite receiver has gone wrong – a new card made no difference – so he can only receive non-encrypted channels at the moment. Sky are suggesting that he moves over to digital, but he doesn't want to be rushed into a decision and would like to get his Nokia receiver repaired or replaced. He wants to know if analogue receivers are still available, and if so where can he get one?            


Expert Reply             Spares are almost certainly available for that model but I suspect the cost of getting it repaired though an approved service agent would be more than the receiver is worth. There's still plenty of analogue receivers available – just take a look in any of the specialist satellite TV magazines -- many at bargain basement prices, but I suggest you look for a second hand receiver. Since the arrival of digital satellite there are thousands of them, in advertising freesheets, magazines like Loot and Exchange and Mart and car boot sales. I've seen complete systems (with dish and LNB) that costs several hundred pounds when new, selling for as little as £10.



Name                Dave Harding, via fax                         

Kit                    Nokia analogue satellite receiver, Toshiba TV       

Problem            Dave's a Video Plus+ fan and wants to know if the new Sky digiboxes are compatible with an external Video Plus+ programmer handset?          


Expert Reply             If Dave's referring to the original Gemstar handsets that were marketed a few years ago then the answer is no, they do not contain the necessary codes to control digital satellite receivers, nor are we aware of any way of updating them. In fact the whole Video Plus+ and digital TV business is still confused. Only tiny handful of VCRs with satellite control facilities, made by Sharp and Panasonic, can work Sky digiboxes, though we understand more are in the pipeline. In theory Video Plus+ shouldn't be necessary on digital TV channels, automated programming was supposed to be a key feature, but we're still waiting for that, and one or two other promised facilities. Doubtless it will all be sorted out one day…



Name                John Carter, via email                        

Kit                    12-year old Hitachi TV   

Problem            John's ancient 25-inch TV has given faultless service, and would probably continue to do so but for the lack of back panel connectors – it only has an aerial socket – which is starting to be a problem. He's after a widescreen set and has narrowed his choice to two 28-inch models made by Toshiba and Goodmans. He notes there's a £175 price difference between the two sets and asks the simple question, is the Toshiba TV worth the difference?        


Expert Reply      We've seen both sets and I for one would be happy to give house room to either of them. Picture on the Toshiba set is just that little bit better though, the image is crisper, colours are a smidge richer and the contrast range is a gnat's wider. There's also the feature list to consider and again the Toshiba set comes out on top so on balance I would say its worth the extra. Nevertheless I urge you to see both TVs in the flesh before you make up your mind because picture quality can be highly subjective, and you may put a completely different emphasis on certain features.



Name                Olaf Kroga, Jeddah, Saudi Arabia                             

Kit                    wants a new TV

Problem            The time has come to replace Olaf's old 21-inch TV. He's been looking around the local shops and noticed a dearth of 16:9 models but a Panasonic TX33P100X, part of the Tau range, has caught his eye. It's built to a local spec, so there's no SCART sockets, but it does have DVD component video input and S-Video. He was about to dip his hand into his pocket when he noticed in a recent issue of HE some advice we gave about not buying big 4:3 TVs any more, in view of the arrival of digital TV. Widescreen and digital TV is still some way off in Olaf's part of the world and one day he will be returning to Europe, so he wants to know how this set will fare with digital TV and DVD? He realises that there will be black bars at the top and bottom of the screen on widescreen broadcasts, but equally 4:3 programmes shown on a 16:9 TV have blank areas at the sides. Should he wait for widescreen sets to reach Saudi, or get the Panasonic TV he's set his heart on?          


Expert Reply             We would never say categorically don't buy large 4:3 TVs any more, but the times they are a changing. The point is UK broadcasters are clearly committed to the digital future and increasing their output of widescreen material. Within the next few years it is likely that most programmes with be transmitted in widescreen format. Since a new TV has a life expectancy of around 8 years it makes sense for anyone about to buy a new TV to think very carefully about the future.


Olaf's situation is obviously more complicated and he doesn't say to which part of Europe he will be returning to, or when. However, according to our information Saudi Arabia uses a variant of the SECAM colour TV system. As far as I can see it's not compatible with the French system and it seems unlikely it will be able to pick up TV transmissions anywhere else in the world. In other words buying a TV locally with a view to shipping it back home – wherever that might be -- seems like a bad idea. If Olaf is going to be in Saudi for more than two or three years, say I would say go ahead and buy your dream TV, enjoy it and sell it before you depart. Otherwise he might as well make do with what he's got, or buy a cheap TV to see him through, and buy a decent telly when he gets home.



Name                Paul Stevens, via email                           

Kit                    Toshiba 2109 DVD player, Yamaha DSP A595 AV amp     

Problem            In the next few weeks Paul is planning to buy a widescreen TV and he has a budget of around £600. He's after a 28-inch NICAM set; he doesn't need any extra sound facilities as he got Dolby Digital on his AV amp. The question is should he go for one with a built-in digital decoder, to give himself some future proofing, or stick with a conventional analogue model?


Expert Reply             Just because a TV has a built in digital decoder don't make the mistake of thinking it's future proof, there ain't no such thing! In fact most of the digital TVs on the market today will need upgrading one way or another in order to receive the full range of services available both now and in the future. TVs with on-board digital decoders are not subsidised like set top boxes, which are literally being given away for nothing. In other words you will have to pay almost the full cost of the built-in decoder which is currently adding between £100 and £300 to the cost of a normal widescreen TV. If Paul wants a widescreen TV now he should go out and buy one, if he wants digital TV as well he should get a free set-top box. Otherwise I reckon he'll have to wait another six months at least before cost of TVs with built-in digital decoders come down to a sensible level.




Everyone seems to be getting quite excited about the prospect of recordable DVD but there's still a long way to go before you will be able to  pop down to Curry's or Dixon's to buy one, and even longer before they're as cheap as VHS VCRs. You might be forgiven for thinking that DVD-R (or DVD-RW, DVD-RAM or DVD+RW, and heaven knows what besides) is making the VCR market uneasy but you would be badly mistaken. VHS has made been around for 25 years and is still going strong, industry pundits are confidently predicting that VHS will continue to dominate the video home entertainment market for at least the next five years. Indeed, if sales of blank tape is anything to go by it is more popular than ever and an estimated 30% of homes now have two or more VCRs.


In 1998 between us we spent almost £100 million buying 46.4 milion blank tapes. The most recent figures for 1999 suggest that has increased to 48.5 million tapes and sales of multi-packs rose by a staggering 187% last October and November. There must have been something good on that week, though some industry insiders suspect that Christmas and the 'milennium factor' was at work with people stocking up on tapes to record the big event and programmes shown over the holiday for posterity.


Recent sales statistics indicate that we're buying more high grade tapes than ever before, they account for just over a quarter of sales. For the record the top brands are TDK with a 15% share, followed by BASF at almost 11% and Memorex at 7%, with strong showings from JVC, BBC, Fuji and Sony but more than a third of all blanks sold are cheaper or 'own-label' brands.







Name                Matthew Newman, via email (**)                                              

Kit                    buying a multi-region DVD player       

Problem            Matthew has a query about multi-region playback. He's poised to buy a Pioneer DV-717 but he's torn between a multi-region model or a dedicated Region 2 only machine. He's read that some 'mods' are unreliable, some discs may not play and the machine's warranty will be invalidated. There are many web sites selling Region 1 titles, he says, and many dealers selling modified players, so what's the score? What are the risks buying a multi-region DV-717?           

Expert Reply Matthew has obviously done his homework and neatly summed up most of the pitfalls in buying a modified player. Quite honestly the whole situation is a mess. In the past few weeks we have seen a succession of budget players selling for less that £200 that will happily play both Region 1 and 2 discs, either straight away or by tapping a simple and well publicised code into the remote handset to disable the region lock.


My feeling is that this recent development could either be the straw that breaks the camel's back and mainstream manufacturers will be forced to loosen their player's regional coding systems, (or abandon them altogether) in order to compete, or efforts to enforce regional coding will be strengthened. Right now it seems like a bad idea to pay for a modded player when you can buy an unlocked machine over the counter at your local supermarket. If Region 1 playback is a high priority for Matthew he might as well get one of these machines the picture performance on the ones we’ve seen is perfectly satisfactory.




Name                Colin Hewitt, via email                        

Kit                    Yamaha surround sound system

Problem            Colin says he is an avid PlayStation fan and is eagerly looking forward to the launch of the new PlayStation 2000, not just for games but because it will play DVDs as well. Colin wants to know if it's worth waiting for the new PlayStation or should he go ahead and buy a dedicated DVD player now?      


Expert Reply             The trouble is we've still got a few months to wait before we know the final score on the PlayStation 2000, its DVD facilities are a bit of an unknown quantity. The other point to bear in mind is that with a PlayStation 2000 you are putting all of your home entertainment eggs into one basket, as it were. If other members of the family want to watch a movie and you want to play with Ms Lara Croft, someone is going to be disappointed. DVD is here now, players are cheap and plentiful, why wait?



Name                David and Philippa Atkinson, via email                           

Kit                    Sony DVP S7000 (Japanese NTSC model)    

Problem            At the moment David and Philippa are on a 3-year secondment in Japan and living in Tokyo. David has brought a Sony DVP-S7000 DVD player, which is a Region 2 NTSC machine; they have built up a fair collection of R2 discs. He says he is worried that these might be incompatible with standard UK DVD players, though he understands the UK is also Region 2. He would like to know if there are any dual standard players available here, that he can buy when they return home, so they can watch their discs.  


Expert Reply             Good news, most DVD sold here will play NTSC discs, and for once regional coding is not going to be an issue. David needs to make sure that any player he buys is in fact NTSC compatible but this is usually clearly marked in the specs. The only other thing he needs to watch out for is the TV. When playing an NTSC disc players normally output an NTSC signal, (rather than the modified PAL that comes out of VCRs with NTSC playback). Not all TVs can handle unprocessed NTSC, so again he should do his homework, before buying a TV.      


Name                Chris Burmajster, via email                           

Kit                    Yamaha DVD-7000 DVD player  

Problem            DVD and audio CD playback on the DVD-7000 are both fine Chris say, but his machine refuses to play CD-Rs. The player simply says 'no disc' when a CD-R is loaded. He's also tried CD-Rs made on a friend's recorder with the same result. Puzzled by this apparent anomaly Chris contacted Yamaha. He was told that it was something to do with the wavelength of the player's laser. Chris wants to know why, if CD-Rs are compliant with the Red Book standard and effectively identical to glass-mastered players, they won't play on his machine. Does Yamaha's excuse sound likely to us?      


Expert Reply             What Yamaha told Chris is essentially correct but for the record the CD-R spec is actually covered by the so-called Orange Book (part II). The laser in a DVD player is optimised to read the much finer and more tightly packed reflective pits on a DVD disc but they will also read plain vanilla factory pressed audio CDs using a variety of tricks, even though it's not actually part of the DVD spec. However CD-Rs are made in a different way to audio CDs. Beneath the crystal clear upper layer on DVDs and audio CDs there's a pattern of sharply defined reflective pits  – the pits represent the digital data. CD-Rs uses a system involving photoreactive dyes in the upper lay of the disc. The ability of the layer to pass light to a reflective layer below changes when it is blasted by a laser beam during the recording process. Put simply CD-Rs are not as shiny as regular audio CDs. This isn't a problem for most recent audio CD players but DVD players with single wavelength laser pickups – designed to read small well defined pits  -- find it a struggle to read the data on a CD-R. That is why some manufacturers have gone to the trouble and expense of developing dual laser pickup systems for their DVD players, one for DVD, the other for CDs.



Name                Chris Donaldson, via email                           

Kit                    Panasonic A110 DVD player  

Problem            For the past year Chris has been having trouble with his Region 1 DVD player and his collection of Region 1 discs. It seems to be somewhat temperamental, at various times the picture freezes, becomes heavily pixellated or breaks up completely. The odd thing, he says, is that three of his movies had the problem when new (The Good The Bad and the Ugly, Bullitt and The Matrix), but now they all play well. However, the same problem has now started with L A Confidential.  This one plays okay until the layer change then it pauses, that continues but becoming heavily pixellated and eventually breaking up. However, he says it played fine when he first brought it. He wants to know if it's a software or hardware problem, or both, or could it just be due to the fact that his Panny player is a first generation machine.


Expert Reply Okay, we're stumped! Of course there could be a perfectly rational explanation for this kind of bizarre behaviour. We have never come across a disc that started out with playback problems and then got better. It seems unlikely that the software on the disc is directly responsible but it could theoretically happen if the surface of a disc was dirty or covered in a film of dust that gradually dissipated with use or was later cleaned. Dust on the laser pickup can have the same effect, if this was dislodged by vibration or air currents then playback would improve, but we're clutching at straws now… It also works the other way around. Playback will steadily deteriorate if a DVD is damaged by careless handling, grubby marks, scratches etc. But seriously, there's no question that DVD players have improved since the first machines appeared just under two years ago and it is quite possible that Chris's player is showing its age or acting all peculiar with some discs but discs improving with age is a new one on us. If any other readers have had similar experiences or a more plausible explanation we would very much like to hear from you.



Name                David Allen, via email                         

Kit                    wants to buy a DVD player  

Problem            If he was to purchase a DVD player that had been modified for all region playback, would picture and sound playback quality be affected, David Allen wants to know? 


Expert Reply             The short answer is no, providing the mod is carried out properly by someone who knows exactly what they are doing. The circuitry in a DVD player that is responsible for regional coding is only peripherally linked to the bits that decode and process picture and sound information so there should be no change to picture performance after a hardware mod has been fitted. The same applies to players with regional locks that can be changed in software. We have come across several cases of ham-fisted DIY attempts at modding, and one or two supposedly professional companies making a botch of it, but that's part and parcel of the risk associated with tinkering around with delicate equipment.






An earlier question about playing CD-R discs in a DVD machine raises some interesting points about compatibility and what you can and cannot shove into your deck so here goes.


All DVD players will also play audio CDs (aka CD-DA or 'Red Book' standard), though officially they don't have to. A fair number of players can read Video CDs (White book) as well, in fact this was quite common on first generation models but fewer decks – particularly budget models -- seem to have this facility these days, even though there are still plenty of Video CDs around.


You may recall a few years ago Phot CD was launched amid much razamatazz by the photographic industry. It was dubbed the 'digital shoebox' a means of preserving cherished photographs on a recordable optical disc, Needless to say it never took off as a domestic format (it has been quite successful in the professional photograhy market). However it never made it onto DVD,

Photo CD is a close relative of CD-R, extra software is required to process the data and display images and manufacturers would have to take out a licence for Kodak.


We think only one DVD player was ever built that could play Cd-i (CD interactive) discs and surprise surprise it was made by Philips, who poured millions into the development of the ill-fated games/multimedia format. Pioneer has cornered the market in players that can read oddball format like CD+G (graphics), which was mostly used for Karaoke recordings. Pioneer also made the only DVD machine (actually it was a combi Laserdis/DVD machine) that was able to play the very strange CDV discs that briefly appeared seven or eight years ago. These were hybrid audio CDs and laserdiscs, with two or three regular CD audio tracks lasting around 20 minutes and a short video 'clip' with analogue video and digital audio. All DVD players can read the digital audio tracks but not the video clip.



Ó R. Maybury 1999 1312


Star letter addresses

(*) Ravi_manoharan@notes.seagate.com

(**) mattyn@madasfish.com



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