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What gain material should i buy?

Discussion in 'Projectors, Screens & Video Processors' started by poopdeck, Apr 9, 2005.

  1. poopdeck

    poopdeck
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    I have a Sharp XV-Z91E LCD projector an Arcam 89 Plus DVD player (Connected via component prog scan)
    I am setting the system up for the third time in a loft space using screen material stretched over a solid frame... in the first set up i used matt material from DRH Screens and in the second i painted a wall in flat matt white emulsion.
    The loft will be totally dark and i liked the matt screen but wondered if i should go higher on the gain... as my luminums are 800 and 1200 contrast.
    DLH recommend the 3.2 gain (Well it costs more!!!) for 1200 lums and below, but i am concerned about getting good black levels.... any thoughts anybody??? :lease:
     
  2. Tempest

    Tempest
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    I'd be interested what others say on this one.

    I've been told figures of 1.3 Gain for LCD. So 3.2 seems stratospheric in comparison with that.
     
  3. Mr Bump

    Mr Bump
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    The higher the gain the (potentially) worse the blacks. If you have a reasonably bright PJ in a nice dark room (which is sounds like you will have), you want as low a gain as possible. I'm sure a nice 1.0 gain matt white screen would work perfectly. 3.2 would be insane - your blacks would be terrible and everyone would get a headache, as it would be too bright - that would mean that it would appear 3.2x brighter than a matt white screen!
     
  4. poopdeck

    poopdeck
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    Thanks for clearing that up... black levels are my main concern, there pretty good on the sharp and my loft will have no ambient light at all. Its brightness level seemed fine when i used 1.0 gain material before so i could stick with it. Are there any other good sources for material other than DRH? :uk:
     
  5. Mr Bump

    Mr Bump
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    No idea, I'm afraid - I've always bought pre-made screens....
     
  6. David_of_Surrey

    David_of_Surrey
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    Of course even a room with no lighting at all with total blackout will have quite a lot of ambient light which is the backwash of the projector reflecting back into the room.

    High gain screens should in theory keep the light from the side walls, but with my DIY blackout screen (supposedly gain 1.0) light wash starts on the ceiling almost vertically above the screen (18 iches above it), which is odd as the proj centreline is level with the top so it shouldnt be coming off it obliquely.

    So the light backwash lightens the room which impinges on the screen and affects the black level.

    Black walls I suppose would help

    Dave
     
  7. Mr Bump

    Mr Bump
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    Yup, that's why I went for black carpet on the walls and ceiling - I get no backwash at all! :D
     
  8. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    If you want to get more light but with better black level the answer would be a grey screen with a higher gain. Basically they are grey backings with high gain topcoats. So they have narrower viewing cones but will lower your black level. Probably looking at 1.2-1.3 gainish for one of these. Stewart Firehawk is an example of one.

    Gordon
     
  9. poopdeck

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    thanks gordon... do you know of anywhere i could buy the material off the roll! i was going to use DRH screens but i think they only supply white material! :thumbsdow
     
  10. ICEAV

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    Re some of the queries here I have a few comments.
    Our Day-Light Digitals screens have a rated pixel resoultion of 9 million pixels. When you compare this side by side to a matt white the matt white looks muddy and certainly the black look crushed and lacking in detail. You will achieve a substainly clearer and sharper image as a matt white screen really does discard alot of information. Though they are rated at 20 Gain the real benefit of this is in well lit rooms. In darken rooms a matt white screen is comparable in brightness but lacking overall with a very flat brightness. Our concave 20 gain screens are able to deliver the same image brightness whether full room lights are on or off, deliver 3D images with depth of 300mm when wearing normal optical glasses.For both the flat and concave versions contrast ratio dramatically enhances the grey scale and uniformity of colour graduations due to the rated 1000:1 . No matter what the projector a Day-Light Digital screen will substantially enahnce what you get from projection on any cloth matt white screen, grey hawk or white painted wall.
    Write to me if you need further details, install pics etc.
    Kevin Andreassend
    Chief Technology Officer
    ICE AV Technology Ltd
    P.O. Box 3030 13
    North Harbour
    Auckland
    New Zealand

    Tel +64-9-414 2348
    Fax +64-9-441 2497
    Email kevin@iceav.co.nz
    Web www.iceav.co.nz
     

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