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,

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Originally Posted by Tomlin

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,

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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

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Originally Posted by mauriceb

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

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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!

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Originally Posted by Tomlin

I hope to see an improvment in quality as soon as I can mount it upside down as well- thanks for the reply!

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

Maurice

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

What a great add-on explanation, thanks for that!