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HD2+, HD3, HD4, HD5 - what's the difference?

Discussion in 'Televisions' started by Tarbat, Jun 27, 2005.

  1. Tarbat

    Tarbat
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    I'm researching what sets are likely to come onto the market in the UK between now and the end of the year. Two main players in the consumer market for DLPs are Samsung and Toshiba.

    Firstly, looking at Samsung, it looks like their older P63 and P67 models us an HD3 DMR. Their new R67 models use an HD4 DMR, and their R77 models use an HD2+ DMR.

    Then looking at Toshiba, all their models use an HD2+ DMR.

    So, anyone know what the differences are between an HD2+ chip and the HD4. What's different about an HD5?
     
  2. Razor

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  3. Tarbat

    Tarbat
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    Thanks Razor, but I've already searched all over that site. All TI quote are chips named 0.7XGA, 0.55SVGA, HD2, 0.9SXGA, 480P, 576P.

    I'm trying to work out which chips have diamond pixels, which have square pixels, and which chips use the "dark metal" technology to improve contrast, etc. Also which chips use "wobble" to double the resolution, etc.

    I think HD3 and HD4 use diamond pixels, giving a "softer" picture than HD2+ chips that use square pixels, for example. I've done a lot of googling on this, but with little success.
     
  4. neilmcl

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    The HD2 and HD2+ have mirrors arranged in a square pattern also offering a 1:1 pixel mapping whereas the newer HD3 and HD4 have fewer mirrors arranged in a diamond overlapping pattern, they also use this "wobble" technology to increase reaction speed and resolution. The HD3 and HD4 are supposed to give a softer, more cinematic look to the picture but to be honest it's not that noticeable and I prefer a less contrasty picture anyway. Any DLPs with a contrast ratio of 2000:1 will use the latest HD4 chips. I think the "Dark Metal" technology has been used on chips HD2+ and above. I've not heard anything about a HD5 chip but the designation could be used for the forthcoming 1080p chip but this isn't released as yet.
     
  5. Liam @ Prog AV

    Liam @ Prog AV
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    HD3 and HD4 are the diamond pixel ones that use "wobbulation". IIRC they use half the horizontal resolution and essentially interlace the image (so for each horizontal line, one pixel on the chip is used to light two pixels on the line). A cost effective way of displaying a high resolution image, but softness issues are true especially as the image needs to be reprocessed to split onto the chip. I avoid these the same way I do ALIS plasma screens (which do a similar thing). However they are much cheaper to produce, I can't see the 1080p wobbler being too much more expensive than 720p non-wobbler. So prepare for an in-flux of 1080p DLPs and hope that the latest version of the wobbling technology isn't as soft as it has been!!

    Now I hate the TI codes as much as everyone else does, mainly because they keep changing and don't seem to follow an order!!! I'll give it a go though:

    HD2 is 720p with proper pixels, HD2+ then used early dark metal technology, closer mirrors, and I think a different angle of tilt all basically combined to give better brightness and contrast.

    DC3 is Dark Chip 3 but this is a technology not a specific chip model number. So I see it as you can have a normal HD2+, or a HD2+ with DC3 in it. This is the newest Dark Metal, is awesome, and is filtering down now to all chip sizes.

    HD3 was the wobbulated 720p (640 x 720?)
    xHD3 is wobbulated 1080p (960x1080).

    These then changed to HD4 and xHD4 but still mean the same resolutions. The 4's having faster switching speed for smoother interlacing of the image.

    I wonder if HD4 is still otherwise the same as HD3, or if some Dark Metal and other technologies have made there way in too. The HD3 is quite an old chip now, outperformed by the HD2+ without the latest DC3! Although I do know the xHD3 (1080p) launched last year did have DC2 technology in it. I've only ever heard of HD3/HD4 being in RPTVs (and haven't seen a HD4 set yet - hopefully one at CEDIA this week), not sure if it will go over to front projection or not.

    What I couldn't tell you is if the HD4 and xHD4 still suffer the softness issues as these are very new out. The xHD4 is likely to appear on some high end single-chip DLPs before the end of this year, and I don't think it's going to be significantly more expensive. So on the surface 1080p for not more than 720p money, but behind closed doors using a different technology that traditionally hasn't been as good.

    There will eventually be a 1920x1080p but God knows when and I am sure it will be very expensive. This might be what the HD5 is?
     
  6. Tarbat

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    Liam, you're a star :smashin: That's one of the best descriptions of the various DMD chips that I've seen - thanks.

    I guess it will be interesting to see how HD4-chipped TVs such as the Samsung SP56L7HX (I think) perform, whether they have the crispness of an HD2+ picture or the softness of an HD3 picture.
     
  7. Br41ns

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    :hiya:

    The SP56 still uses the HD2+ chip thats in the SP50 however it uses a bigger colour wheel to try and cut down on rainbows. They do have an HD4 model on the horizon which i believe is a 1080p screen which i also believe uses the wobulation thingy on the chip.
    Heres the specs on the sp56 if you're interested.

    http://www.samsung.com/au/products/tv/rearprojectiontv/sp_56l7hx.asp?page=Specifications
     
  8. Tarbat

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    Yes, I know the L7 models use an HD2+ chip, but I thought the L6 models were using an HD4 chip - but I might be wrong.
     
  9. Br41ns

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    :hiya:

    If you go to www.avsforum.com which is an american site there is alot of pics and specs of the upcoming sammy ranges, if the L6 is 1080 then it looks like HD4 from reading about the CES show.
     
  10. Tarbat

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    I thought the L6 range was equivalent to the 67 series in the US, so 1280x720 - like this.
     
  11. Razor

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    Samsung definately have a good stlyist. I love the look of their displays. :thumbsup:
     
  12. Br41ns

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    :hiya:

    Smart looking set, not too sure what DMD will be in it but judging by the other sammys it should be damn good. :smashin:

    Hi Razor :hiya:
     
  13. Tarbat

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    Some more research reveals that the HD4 chip is classified as "Cost Effective", the HD2+ as "For High Demands", and the xHD4 as "The Best". HD4 is wobbulated 640x720, whereas HD2+ is full 1280x720. xHD4 is also wobbulated, but 960x1080. HD4 is going to give a smoother picture, HD2+ a sharper picture. HD4 has higher contrast than HD2+.
     
  14. Razor

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    So many chips and not a battered fish in sight :D

    br14n :hiya:

    Why are they using lower res for the newer chips????? Its a shame that you cant swap the chips out as you do in pc's. I wont upgrade untill they have a 1920x1080 chip which can do 1080p.
     
  15. Liam @ Prog AV

    Liam @ Prog AV
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    Cost. The only dedicated 1080p chip is the 2048x1080 Digital Cinema chipset which costs literally thousands of pounds. The xHD4 is nice and cheap, so manufacturers can effectively say 1080p resolution but at prices that aren't too significantly higher than previous 720p models.

    Swapping out would be nice, but also impossible. The chips are physically different sizes, I guess you could swap between the different .55" chips, but one is 848x480 and the other a wobbulated 640x720 so the driving electronics wouldn't know what to do with it! Change the driving electronics over as well and you might as well buy a new TV/PJ.

    If I were you I wouldn't upgrade until true 1080p either, that RD65 is fantastic... well apart from the one obvious shortcoming :rolleyes:
     
  16. NicolasB

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    The xHD4 can do 1080p. You have to remember how DLP actually works: any given pixel is either on at full brightness or off, there is no in-between value. So, to simulate variations in brightness, each pixel flashes on for only a fraction of the time available: on for the entire sub-frame we perceive as maximum brightness, while flashing to the same brightness but with a shorter flash looks dimmer.

    In addition (other than with ultra-expensive 3 chip devices) there are at least 3 (and probably at least 6) separate flash cycles per frame, one for each colour component. The brain then (if you're lucky) combines separate red, green and blue flashes into a single coloured flash, and coloured flashes into a steady pixel with variable brightness.

    So, whenever you're watching DLP, any given pixel on the screen is constantly flashing on and off anyway. In this case you're using the same mirror to handle two pixels - but you're still looking at a whole bunch of pixels flashing on and off. This is a true 1080p display no matter how you look at it. Probably less prone to rainbows than a non-wobulation chip too, as the colour wheel has to spin twice as fast.
     
  17. Liam @ Prog AV

    Liam @ Prog AV
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    I'm entering the realms of pure speculation here - but if the HD4 and xHD4 wobble twice as fast as the HD3 and xHD3 then I assumed that this means the pair of pixels drawn from the single mirror are going to be done in the same time a HD2+ would draw one pixel from one mirror i.e. getting both wobbles out before rotating the colour wheel to the next segment therefore similar colour wheel speeds to before.

    Remains to be seen in the flesh how good this chip actually is. Must be pretty damn good for companies like Barco and ProjectionDesign to say they'll have production units available end of this year. I'll remain scepticle until I see it, still sounds like ALIS on it's side to me!!!
     
  18. Razor

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    :thumbsup: Liam

    Thanks for saying the RD65 is fantastic, shame no one is buying them. After all the hassel I had with my RD65 I am content using a HTPC and powerstrip for my region 1 DVD's.

    I would love to own a 1080p 82' rear pro one day. :clap: :clap: :clap:
     

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