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lack of contrast on sony hs10

Discussion in 'Projectors, Screens & Video Processors' started by johnkay, Jun 18, 2003.

  1. johnkay

    johnkay
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    After 89hours of use I find that picture seems to have gone down in contrast. I always use the dynamic mode which gave me wonderful results in the begining but now seems just ordinary. I don't know if it is because I have got used to it or if the lamp has aged. I am using the free 6ft screen that came with it, but I am seriously considering putting up an 8ft pull down screen but now I am wondering if on the 8ft screen I will loose even more contrast and brightness? The bigger the screen the duller the picture, is that correct? Also I usually use the pj once a week and when not in use I unplug it and put it away, is it better to leave it in standby when not in use? I am using it with a pioneer dcs303 s-video. Any thoughts would be much appreciated.
     
  2. LTJ

    LTJ
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    Hello John.
    Right. I'm going to try and stay non-contentious and apologies in advance to any one I may inadvertantly ruffle.


    Okay John. it's my belief that pj's go off the boil very quickly for several reasons
    1) the lamp output starts very brightly drops slightly and then sort of starts a slow decline untill it falls off rapidly.
    in other words , it's not a linear out put of light but rather more a stepped decline


    2) Now this is my greatest concern with PJ's (I've only experienced LCD models -three so far. This concern is that of atmospheric grime on the optics and lenses. (soory all but I really do believe that this is an overlooked/unstated issue)
    If you look off beam on the out-put of your pj -you will see millions of particles in the atmosphere catching the light out-put. Now imagine this stuff getting sucked into the pj by the cooling fans (it would also get in even if the pj wasn't on !. But not I would guess to the same level)
    This atmospheric soup of dead skin, aerosoles and smoke., surely get on to the optics (and there's at least 25 glass/lcd surfaces that teach beam of RGB has to go through. Just a slight minute covering is enough to start making the surfaces become increasingly opaque and thus reflecting light back into the transmission system.
    Now as to cleaning these surfaces ? is very tricky a) they are very diffilcult to gain access to , and secondlly cleaning them can cause damage to the surfaces i.e. microscopic scratches.
    So all in all there's not a simple solution. Mt Panny 100 is on 248 hrs and that is now just starting to shows signs (despite a filter system) of the image going off and becoming apparent on dark scenes, with a tendency towards green.

    3) Theres possibly a 'taking it for granted phase as well'

    Okay rambling as usual. But I really don't know of any solution to the problems I've outlined in 2, bar that of a very clean atmosphere (in my case a pre-filter) and regular cleaning.


    This is all based on my own opinion, and I'm probably totally wrong.
     
  3. museumsteve

    museumsteve
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    interesting read mate and probably spot on..so now, what is the solution.? anyone.!!
     
  4. Messiah

    Messiah
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    A sealed optic pj? (like HT1000 - come on NEC bring out that 16:9 version)
     
  5. johnkay

    johnkay
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    Very interesting reply from LTJ, so why don't Sony and others try and make improved replacement lamps, i.e increase contrast ratios by just changing lamps and/or make them auto- cleaning to keep them in top condition. It is poor that after less than 100hrs out of 2000hrs the degradation in performance has become noticable. They should not boast about how good the picture is but tell you how good it is when the lamp has been bedded in.

    Also is it better to leave the pj in standby,that is left plugged into mains when not in use, or does it not matter.

    Will I lose a lot more contrast on an 8ft screen compared to the 6ft that I am currently using, if so should I try and get a screen with a gain?.
     
  6. John_N

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    Have you had any "false starts" with your unit? My first HS10 suffered from false starts and was noticeably dimmer after 120hrs than when new. The new replacement unit hasn't suffered from false starts and after 200hrs the bulb has not dimmed noticeably.

    If you have really noticed that big a difference after 80hrs I would suspect that your particular unit has a problem / is excessively dirty / has a faulty bulb because really less than 100hrs is excessive for such a large drop off in performance that you claim.

    Are you operating your unit in "cinema black " mode or not? you mention dynamic which by default leaves the lamp running at high power. If this is the case, then maybe the lamp shows more detioriation. I personally run mine with the lamp in low power "cinema black " mode to increase lamp life and improve black level.

    J
     
  7. citreon

    citreon
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    please as i also have a hs10
     
  8. Kramer

    Kramer
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    Was gonna suggest you do a quick search but thought I'd save you the trouble.

    Search function isn't working at the mo though :( Never seen that before :confused:

    Hope it's back shortly.

    :smoke:
     
  9. John_N

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    False starts are when you turn on the projector and the lamp doesn't come on (the fans do) usually with the lamp/cover light flashing as well. Then the projector turns itself off after about 3 minutes. This tended to happen with a certain batch of units that allegedly had faulty lamps and what would happen is that the projector would fail to start sometimes, and the problem would sometimes get worse, sometimes get better, but often resulted in the lamp losing output earlier than usual or even failing early.

    I had this problem and after 120hrs my projector would usually take several "tries" to start and I noticed the bulb was quite a bit dimmer too.
     

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