Hi everybody.
While assembling my PJ I discovered this useful info.
My DIY Projector: http://www.diyaudio.com/forums/showthread.php?s=&threadid=43441
When I first Assembled my whole PJ, I discovered that the image was projected up. That is to say: I placed the PJ at 60cm from the floor, and the projected image (PJ @ 250cm from the wall) was at 45cm from the floor and 130cm in height. The projected image was displaced upwards, relative to the projector placement.
With this setup it was impossible to place the projector hanging on the ceiling, cause part of image would be projected over the ceiling. And inclining the PJ, so as to fit the image on the wall, would cause a trapezial image.
So I enverted the Fresnel Lens that goes towards the Lamp, and got the inverted effect. Now If the PJ is placed near the floor, the pjected image, was displayed part of it on the floor. What makes it good to place it Hanging from the ceiling. (Just what I wanted)
Basically you need to displace from the central axis, the first Fresnel´s center. Up or down, depending on where you are going to place your PJ.
Warning: This info is based on my personal experience. It should work with projectors with similar setups than mine.
If you visit my project, I don´t say anything about the second fresnel. You can see the Fresnel that goes towards the Projector Lens, but not the one that goes towards the lamp. It´s placed inside the LCD Box, close to the lcd, in the way that is discussed previously.
I attach a scheme of this for better understanding.
While assembling my PJ I discovered this useful info.
My DIY Projector: http://www.diyaudio.com/forums/showthread.php?s=&threadid=43441
When I first Assembled my whole PJ, I discovered that the image was projected up. That is to say: I placed the PJ at 60cm from the floor, and the projected image (PJ @ 250cm from the wall) was at 45cm from the floor and 130cm in height. The projected image was displaced upwards, relative to the projector placement.
With this setup it was impossible to place the projector hanging on the ceiling, cause part of image would be projected over the ceiling. And inclining the PJ, so as to fit the image on the wall, would cause a trapezial image.
So I enverted the Fresnel Lens that goes towards the Lamp, and got the inverted effect. Now If the PJ is placed near the floor, the pjected image, was displayed part of it on the floor. What makes it good to place it Hanging from the ceiling. (Just what I wanted)
Basically you need to displace from the central axis, the first Fresnel´s center. Up or down, depending on where you are going to place your PJ.
Warning: This info is based on my personal experience. It should work with projectors with similar setups than mine.
If you visit my project, I don´t say anything about the second fresnel. You can see the Fresnel that goes towards the Projector Lens, but not the one that goes towards the lamp. It´s placed inside the LCD Box, close to the lcd, in the way that is discussed previously.
I attach a scheme of this for better understanding.
