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Thread: Adjusting scan angles

  1. #1
    Bradfo69's Avatar
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    Default Adjusting scan angles

    O.k. so, I'm beginning the foray into this whole "tuning" thing as I believe mine may be a little "out". I've figured out that what I'm trying to adjust are Scanpro 20's. Yeah... I know... but, that's what are in this particular projector. Anyway, according to Adam's tuning guide, the first step is to reduce the scan angle down to 8%. I'm using LD2000 and can't find anything referring to the scan angle.

    I understand adjusting the image "size" in the "projector settings" which I usually leave at 100% although I will occasionally lower it a little to get graphics to fit on a wall if the image is traveling a fair distance. If I drop THAT down to 8%, the image is so small, you can't see the damn test patterns. It's just a bright spot. That leads me to think I ain't adjusting the right thing. I searched the Help menu for "Scan Angle" and didn't find anything referencing it. I also see in various adds for scanners that it's so many "points" at "such and such" a scan angle. Where do I adjust the scan angle?

    I'm aware that graphics on 20k scanners aren't going to be great. I'm just trying to get the roses in Laserguys Breast Cancer Awareness show to look like roses. I've also noticed circles don't seem to close and have tails trailing from the break in the circle. Text is illegible etc. I slowed the scanner speed down to about 14k and the image improved significantly and more closely matched the preview pane but, so did the flicker. After looking at various test patterns, I'm thinking a tuning will at least offer SOME improvement.

    And why make 12, 20 or 25k scanners in the first place since everything seems to use 30k as a benchmark?

    There are other questions related to this projector. Does it sound logical that noise like a bad fan would be coming from inside a module? This projector is noisy as hell and it's not a case fan. I thought at first it was the scanners running even without light output but, I think I've narrowed down the noise to the green module and it does appear to have ventilation holes on the back end. The noise is constant from the time it is turned on. I also though it could be from a power supply. It's been hard to isolate but, I believe its coming from the green module.

    I'll have other questions appearing soon - some of which I've been holding onto since SELEM. I've been trying to read through threads and find the answers first but, I'm not finding answers to a number of them. (Such as, what the hell is a Kip Kay project?) LOL

    Thanks in advance! ~Brad

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    Default thought I posted this an hour ago...


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    Default

    On the same topic, I have just fired up my first projector using QS/LivePro and at a distance of around 12 foot my max image width is around 2 foot.
    I have maxed the size in projector settings, does this sound aboout right (using DT25's) or do I need to adjust the scan angle on the scanner amp?

    Cheers

  4. #4
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    Default

    It's not a simple case of setting the scan size to 8% in your software...

    Most scanners will scan a max angle of +/- 30 degrees, so you need to do a bit of math...

    Pangolin have a page dedicated to calculating scan angles here: http://www.pangolin.com/userhelp/scanangles.htm

    Hope that helps

    Mark

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    Default Scan Angle Calculator

    Works great!

    (Get the updated version)

    http://www.photonlexicon.com/forums/...gle+calculator

    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

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    Default

    Thanks for all the replies.

    The calculator is great!

    So, @ 12feet I have a pattern of 22 inches giving me a scan angle of 9 degrees.

    Where do I go from here?

    The DT25 manual says they have a max scan angle of 60 degrees, I would be happy with 30-40 degrees.

    Last thing I want to do is damage my scanners, so do I start to turn up the image size on the scanner amp until I reach my desired scan angle and does what I am projecting (image) have a baring on any of this?

    Thanks again.

  7. #7
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    Default

    Generally, for our purposes, scan angle = image size.

    Using one of the test patterns and the scan angle calculator, adjust the image size under the "projector settings" that gives you the image width required to match the 8 degree scan angle.
    Once that is set, you tune according to Buffo's guide.

    Once tuned, that projector setting becomes your "keystone" setting for graphics set at 30K. (You should still be able to get close with your 25K set).
    For beams, you could adjust "image size" for a wider scan angle as needed, and return to your 25K/30K "Image size" setting when running graphics.

    The max scan angle advertised by most scanner sets would only be good for very simple, very basic graphics and beams.

    Good luck with the tuning!
    It can be a bit tedious and time comsuming, and I'm convinced it's an art form in and of itself!
    Keep Buffo's guide handy, give yourself plenty of time, and you should be fine.

    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

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