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Barco and shimming lenses question....

Discussion in 'Projectors, Screens & Video Processors' started by theritz, Nov 19, 2004.

  1. theritz

    theritz
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    Hi,

    With the prospect of ceiling mounting a Barco 701s, and having a screen-drop of 19 inches, I'm concerned that if I mount the Barco level with the height of the screen I'll have a CRT lens shaped dent in my forehead before long..... :blush:

    I'm very reluctant to sacrifice my current screen position, but if I mount the pj near flush with the ceiling I'll have 3 or 4 degrees of tilt (on top of the 10.5 built into the projector)... I could reduce this to 2 and still have the projector out of harms way, subject to some more fun and games with the lens program and a measuring tape.

    All the stuff I've read about super setups lay great stress on having the projector level - and I understand why. Having seen pictures of james installing Phil Hinton's projector levelling it with a spirit level, as well as reading loads of other stuff, I am obviously anxious not to create focus problems for myself, which I understand is the greatest risk. I have waited a long time to dip my toe into CRT water and I want to get it right.

    My question is whether I can shim the lenses to compensate for any additional tilt - I've seen Roland refer briefly to this in the dim distant past, but have come across nothing despite fairly intensive reading on the net (this is, no doubt tempting fate - someone somewhere may have a link to a site explaining this in detail.... or maybe not.)

    If shimming is a viable proposition, where do I get the shims, or do I have to make them, and is there a means of calculating the "degree" of shimming required.

    I intend to do a "coffee table" mount during a trial period, so will have the chance to experiment with the degree of tilt and see whether I can come up with an aceptable compromise - I intend to construct a base which will allow me to alter the height of the table and tilt the top to mimic different positions before finalising a ceiling mount plan, to see how it goes.

    If shimming is excessively complex (or requires the experience gained from professional installing), I'd like to know up-front. If there is a significant material downside to the approach, that would also help.

    On a side note, could someone tell me what the substantive diference is between a 701, 708 and Cine7 ??


    Thanks in advance,

    Sean.
     
  2. Roland @ B4

    Roland @ B4
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    Sean happy to answer the shim question.
    The best method to use is trial an error. Install the projector and losen the bottom two bolts holding the lens on and just pull it forwards and you will get an ideal of the thickness required. You are only talking 0-2mm

    The barco lens program gives you the figures in the text option.

    Getting shims will be tricky. I tend to use kitchen foil or kitcat wrappers and inserted close to the bottom bolt. If the angle is big enough you could ad some string spring washers and tighten against those.
     
  3. theritz

    theritz
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    Roland,

    Many thanks........ I appreciate the reply. I suspect that this might be something where your experience counts for more than reaidng stuff in manuals - I'll have a trial set-up and see where it goes from there.

    Sean G.
     

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