What kind of max screen size is realistic with a CTR Proj.?

Discussion in 'Archived Threads 2001-2004' started by Luke_Y, Dec 27, 2002.

  1. Luke_Y

    Luke_Y Second Unit

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    Assuming say; an 8" CRT Proj. such as a Ehome Marquee 8000/8500 in a completely light controlled room. As the screen gets larger light output becomes the problem. So what do you think the max diagonal screen size is on a 16:9 screen before you have to drive the Proj. so hard that "Blooming" becomes an issue?
     
  2. Jim Ferguson

    Jim Ferguson Stunt Coordinator

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    I have an 8" Barco CRT projector with a 110" diagonal 16x9 screen. I certainly wouldn't go any larger, but it seems to handle this size OK.
     
  3. Bill Lucas

    Bill Lucas Supporting Actor

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    Luke,

    I've seen Jim's setup and it looks wonderful (although there may be a different video processor in his system now). I agree that you shouldn't go larger. 96" X 54" is IMPO, about the limit.

    BTW, blooming is not the issue at hand. The problem with overdriving a CRT is that you will burn the phosphors on the face on the used portion of the CRT. Proper light output, greyscale and color purity will be lost as a result. Regards.
     
  4. Luke_Y

    Luke_Y Second Unit

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    So do you think it would be fairly safe to say that a 120 inch diag 16:9 screen would be pushing an 8 in CRT too hard or that there just wouldn't be enough light output?
     
  5. Bill.P

    Bill.P Extra

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    I've consulted the experts, and the word in about 16 to 20' diagonal should be fine. Of course screen type/gain would come into play here also.
    -Bill

    [experts= my dad who works on Electrohomes/Barcos/etc.]
     
  6. Sean M

    Sean M Stunt Coordinator

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    You could do a 120" diagonal 16x9 screen without driving the CRT's too hard if you use a screen with a gain of about 1.8 and are happy with only 9 foot lamberts of light output (commercial theaters have about 12 with film running in the gate). Going for 12 ftL or using a screen with lesser gain at that size would be pushing it. It won't look as good as it would on a smaller screen, particularly the brightness, but it would work.
     
  7. Luke_Y

    Luke_Y Second Unit

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  8. Parker Clack

    Parker Clack Schizophrenic Man
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    Luke:

    I projected a Zenith FPTV with 7 inch CRTs on to a 120 inch diagonal flat white painted wall for over 3 years with no problem. I did have it set up in a totally dark room though. Light control is a must with any CRT projector.

    I would think that you would do fine with a 120 inch screen with the Ehome projector that you have in mind.

    Parker
     

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