Results 1 to 6 of 6
  1. #1
    1000+ Poster - Fantastic Contributor Tomlin's Avatar
    Join Date
    Nov 2005
    Location
    Waycross, GA
    Posts
    1,188
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Projector Image Spills

    Hi all

    Last night I noticed for the first time that although I have my FS image squared up using the Keystone functions, I can still see a 'halo' of sort that is not affected by the keystone utility. Is this normal? Im thinking that it's normal to have an area of light that is outside of the actual image, but maybe it's not corrected due to the angle that I have the projector mounted at.

    Speaking of the projector's angle, Im now seeing that (once I have the visual sytem permanently mounted) it's definately to the advantage to have it upside down vs. right side up, as the projector appears to naturally want to project up, therefore when mounted upside down, it's going to be easier to position the image in relation to the sim.

    Thanks,
    Eric Tomlin-
    Learjet 45 Builder
    www.flightlevel180.org

  2. #2
    500+ This must be a daytime job mauriceb's Avatar
    Join Date
    Dec 2005
    Location
    Gravenhurst, Ontario
    Posts
    544
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Quote Originally Posted by Tomlin View Post
    Speaking of the projector's angle, Im now seeing that (once I have the visual sytem permanently mounted) it's definately to the advantage to have it upside down vs. right side up, as the projector appears to naturally want to project up, therefore when mounted upside down, it's going to be easier to position the image in relation to the sim.

    Thanks,
    I do believe that most projectors mounted on the ceiling are meant to be mounted upside down. For one thing, the manual controls are often on the top of the projector and also the image tends to be projected upwards as if the projector is meant to be sitting on a table as are most portable presentation projectors.

    So, the keystone correction needed is much higher if you mount the projector on the ceiling in the same way than if it was sitting in a table. If the projector is upside down, the image quality will be better since keystone correction does degrade the image somewhat especially if extreme correction is needed.

    Also, try playing with the various image controls. I thought that my image was not as sharp as it should be and I was right. I can't remember what setting fixed it, but it may have been image shift or something like that.

    Maurice

  3. #3
    1000+ Poster - Fantastic Contributor Tomlin's Avatar
    Join Date
    Nov 2005
    Location
    Waycross, GA
    Posts
    1,188
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Quote Originally Posted by mauriceb View Post
    I do believe that most projectors mounted on the ceiling are meant to be mounted upside down. For one thing, the manual controls are often on the top of the projector and also the image tends to be projected upwards as if the projector is meant to be sitting on a table as are most portable presentation projectors.

    So, the keystone correction needed is much higher if you mount the projector on the ceiling in the same way than if it was sitting in a table. If the projector is upside down, the image quality will be better since keystone correction does degrade the image somewhat especially if extreme correction is needed.

    Also, try playing with the various image controls. I thought that my image was not as sharp as it should be and I was right. I can't remember what setting fixed it, but it may have been image shift or something like that.

    Maurice
    Thanks Maurice.

    Although not evident in my earlier post, I do realize that it will need to be mounted upside down if mounted to the ceiling but for now it's mounted on top of a temporary gantry of sorts until I complete the shell, and so I do have to use quite a bit of keystone correction for the time. I hope to see an improvment in quality as soon as I can mount it upside down as well- thanks for the reply!
    Eric Tomlin-
    Learjet 45 Builder
    www.flightlevel180.org

  4. #4
    500+ This must be a daytime job mauriceb's Avatar
    Join Date
    Dec 2005
    Location
    Gravenhurst, Ontario
    Posts
    544
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Quote Originally Posted by Tomlin View Post
    I hope to see an improvment in quality as soon as I can mount it upside down as well- thanks for the reply!

    I'm quite sure you will see a difference. Keystoning correction has a price

    Maurice

  5. #5
    25+ Posting Member
    Join Date
    Nov 2005
    Location
    San Diego, CA USA
    Posts
    60
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Keystoning is simply digitally "filling in" or "scooping out" pixels- the actual projection is always 1024x768 or 1280x1024 or whatever resolution your projector is set to. The halo you see is the cutaway pixels or digitally introduced black pixels and they are at the black level that the projector can do.

    Maurice and you are both right that projectors are usually designed to project slightly upwards and hanging it upside down will help. If your projector has "lens shift" you can eliminate some distortion, but if not, getting the flattest projection angle is the best.

    Steve

  6. Thanks Trevor Hale, Tomlin thanked for this post
  7. #6
    1000+ Poster - Fantastic Contributor Tomlin's Avatar
    Join Date
    Nov 2005
    Location
    Waycross, GA
    Posts
    1,188
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    What a great add-on explanation, thanks for that!
    Eric Tomlin-
    Learjet 45 Builder
    www.flightlevel180.org

Similar Threads

  1. DIY projector using overhead projector?
    By nosecone in forum Cockpit Outside Visualization
    Replies: 5
    Last Post: 11-05-2009, 04:04 PM
  2. Faded Image
    By paulj in forum PM Boeing GC
    Replies: 4
    Last Post: 08-03-2008, 09:13 AM
  3. (HELP)Image Projection
    By Trevor Hale in forum Cockpit Outside Visualization
    Replies: 7
    Last Post: 07-19-2008, 03:46 PM
  4. Using Mirrors with projector to make short throw image
    By wannabeaflyer in forum Cockpit Outside Visualization
    Replies: 7
    Last Post: 10-25-2007, 08:29 PM