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Projector Noise

Discussion in 'Projectors, Screens & Video Processors' started by popo, Aug 18, 2004.

  1. popo

    popo
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    Whilst brightness, contrast and picture resolutions are trumpeted by most manufactures, not much consideration seems to be given to fan noise. What is considered to be a reasonable noise level and how best is it to make a comparison between models given un-domestic nature of most retailers?

    Also, does DLP fair better or worse than LDC? Thanks.
     
  2. Stinja

    Stinja
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    On the contary i think fan-noise is being addressed for the home-cinema targeted PJs. Some of the Sony PJs were very noisy, but all the recent LCDs have been quite quiet, at least on low-bulb power. I would expect new models to also get quieter and quieter - the forthcoming AE700 is listed as 27dB, while the Z3 is 23dB!

    Sorry but i cant comment on DLPs, rainbows do my girlfriends head in...

    Personally i'd like manufacturers to address internal dust problems more than anything else. Not sure why they dont seal the optics (expense?), or at least design them to be easier to clean...
     
  3. RTFM

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    Personally i'd like manufacturers to address internal dust problems more than anything else. Not sure why they dont seal the optics (expense?), or at least design them to be easier to clean...[/QUOTE]

    I think the main problem with sealing the optics in LCD projectors is heat dissipation.
    The panels and polarising filters are easily damaged by excess heat.

    Jeff :rtfm:
     
  4. pez

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    isnt the light that comes out of lcd projectors supposed to be polarised?

    pez
     
  5. RTFM

    RTFM
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    The light from the lamp is split 3 ways by dichroic mirrors and filters and passes through 3 polarising filters before passing through the 3 lcd panels so the light coming out would be polarised.
     
  6. pez

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    thats what i thought, but the ae500 lcd projector doesnt output polarised light.

    ive got a few linear polarisers that i picked up from jessops (im planning a passive 3d stereo projection system...see my tag line), and when i put the filter in front of the projectors lens it just dimmed the light slightly, when i rotated it i expected to see some colours just fade out, but it didnt happen.

    there was no difference in image quality as i rotated the linear polariser.

    are they depolarising the polarised light that passes through the lcd panels? if so, how?

    pez
     
  7. theritz

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    pez,

    You might find This pdf explaining LCD and DLP technology helpful..... if it's too low-level then ignore...

    This pdf and This one too might be helpful as far as passive 3d (I assume this means stereoscopic...) is concerned.


    Sean G.
     
  8. pez

    pez
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    yeah ive seen all that before, and it was the first of the pdfs on the 3d stereo displays that had me worried about whether or not an lcd projector that had light from 2 colours polarised 1 way and light from the 3rd colour polarised the other way would be able to have that light passed through another linear polariser.

    turns out its not an issue with the panasonic ae500 as the light that is emitted isnt polarised at all.

    question is how are they depolarising it, and why?

    pez
     
  9. Stinja

    Stinja
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    Errr... yeah so thats where design comes in. Surely it cant be an insurmountable problem to dissipate heat? Im sure most consumers would be happy if it cost £100 (or whatever) more to resolve this, but they got sealed optics, and hence much fewer dust probs. Seems to be the number one complaint of actual hardware issues - apart from specifications vs expectations...
     

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