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Iscan Ultra + PMA400E

Discussion in 'Plasma TVs' started by zorg2000k, Jun 30, 2003.

  1. zorg2000k

    zorg2000k
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    Need some help if poss

    :smashin:

    I'm thinking of buying a Iscan Ultra to use with my Hitachi PMA400E plasma. I mainly use my plasma for sky. My question is will the Iscan Ultra improve my overall sky picture ?

    Also will it stop Sky digital problems where the reds can be jagged especially on dialgonal red lines ?

    cia

    Zorg
     
  2. GadgetObsessed

    GadgetObsessed
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    I too am looking for an answer to a similar question - is an Iscan Ultra useful with ANY of the ALiS based screens?

    The reason I am asking is that I know that the Alis screens are naturally interlaced but generally accept a progressive source. I have seen a post from one Hitachi owner saying that progressive scan (from a DVD) did actually look better than interlaced despite the interlacing in the screen itself.

    Also is there anyone out there with one of the panasonic/toshiba (480 line) screens that is using an Iscan. Does the Iscan improve the image even when the resulting PAL signal is being down scaled?

    Sorry to hijack your thread Zorg :)
     
  3. Andrew_B

    Andrew_B
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    I think that the 'jaggies' you are seeing on diagonal red lines is a symptom of what has been described as the 'interlaced video problem'. I see this a lot on my Sony CRT, but I don't get it at all on my Panny4 plasma via iScan Ultra. In fact it looks awful on my CRT, almost a 'sawtooth' effect and I see it more on US import stuff on SkyOne/Mix. I suspect that you may still see this effect if your Hitachi is the interlaced version, even if you use a de-interlacer and feed it a progressive signal. Could you arrange for a local dealer to allow you a demo of the Ultra, or perhaps you might contact Ivojo for some advice on this and/or a demo unit?
     
  4. StooMonster

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    This is called the chroma bug -- many DVD players have it too.

    Click here for best guide to chroma bug see Figure 7.

    Yes the iScan Ultra has a setting called "chroma filter" that removes the chroma bug from Sky digital (NTL digital, etc.) output -- and very good it is too.

    StooMonster
     
  5. Andrew_B

    Andrew_B
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    Looking through the chroma bug special report, I notice that the 'jaggie' effect is actually referred to as the 'Interlaced Chroma Problem' in the section headed 4:2:0 Interlaced: Fundamentally Broken. This effect is much more noticeable than the CUE chroma upsampling error, and is most likely to be what you are seeing. Although the report indicates that this problem is completely fixed by using the iScan Ultra, I've got a sneaky feeling that you're still going to get it on an interlaced display device, if that's what your Hitachi is. Like I said, get a demo, it's the only way you'll know for sure. I'd be interested to know the outcome.
     
  6. PVR

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    Testing it is vital. I have had the Iscan Ultra which did not do anything good on my Pioneer 433 MXE. Also, when Gordon came to calibrate my screen, he brought the Vision which also caused a lot of problems so he gave up with that.

    PVR
     
  7. symanski

    symanski
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    Don't forget that the iScan's best input is component video, so a converter should be used between Sky and the iScan.

    If you don't, then the iScan would be forced to using composite video, which is a poor quality signal to start with. Some Sky systems are supplied with S-Video (mainly Sky +), which does help, but to ensure a good picture out, you've got to put a good picture in.

    All the best,

    Dr John Sim.
     
  8. StooMonster

    StooMonster
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    I think that you won't get jaggies from chroma interlace with iScan Ultra, because the ALiS screens digitize and then interlace any incomming progressive signal; and as the chroma problems will have been removed by the iScan Ultra (which is outputting a progressive) there is no further chroma problem introduced anywhere.

    StooMonster
     
  9. zorg2000k

    zorg2000k
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    Thanks for the reply,

    I already have a JS-Tech RGB2YUV so I should be ok from Iscan to PMA400E I think ?

    Cheers

    Zorg
     
  10. Andrew_B

    Andrew_B
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    ...you could be right there Stoo.
     
  11. symanski

    symanski
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    Perfect.

    All the best,

    John.
     
  12. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    PVR: Can I just say that subsequent testing showed the major problem with the Vision was due to the Component transcoder. When used on another manufacturers plasma later that day the same problem was present. When removed from the loop it went away. The other issue (half height tearing) is a Pioneer native refresh issue that is only apparent at certain refreshes. There are folk using Visions at refreshes above 70Hz with minimal issues.

    Please do not think from this that I dismiss Johns converters as I do not. They are the best. I believe it has to do with earthing of his boxes, the floating earth of Sky boxes and the floatinbg black level of Sky boxes and the possible earth loops induced in the video chain with all these things. Video is f...ing tricky. What works one day might not the next.

    If I'd have had time and some more tools we might have got closer to a resolution with your MXE. My fault for not being prepared enough!

    I was at another chaps tonight who had anm MXE and I demo'd him a Vision and it was a major improvement over the 5002 board in the plasma.......win some , lose some..

    Gordon

    Gordon
     
  13. slyborg

    slyborg
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    Hi,

    Unrelated really to the thread although I have been considering the iScan and the converter box from JS but what is a Vision (no drug induced references pls :) ) and whats all this I hear about having Gordon round?

    Would I be right in saying Gordon is the John Harvey Jones of the AV world for all us poor AV novices?

    Si
    PS: Also is it retailer dependant as to whether you can trial the iScan or should you just get it and rely on the 7 day cooling off period if it doesn't seem to make much difference?
     
  14. symanski

    symanski
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    There's no earth, the converters are all double insulated so that an earth connection isn't required. If you look at most a/v equipment you'll find it's done the same way. By not using an earth at this point it helps you design a grounding system if one is required.

    Each video device should analyse the black level of the input signal and adjust to suit.

    All the best,

    John.
     
  15. Dutch

    Dutch
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    Hi Si,

    Gordon is an ISF qualified calibrator and travels around the country calibrating plasmas, RPTVs and CRT TVs. The Vision is a video processor made by Lumagen - check out Gordon's website at www.convergent-av.co.uk for more details.

    Steve
     

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