by HoloM » Wed Sep 24, 2014 10:36 pm
Ok i bought a satinized Glass, which Seems to be etched or sandblasted, because it has one rough side. Seems to work, but I have still a question, it's 30x40 cm and I light it with a small lens about 1,5 m away. If you look at the glass there is still a dependency of the angle where you look at in brightness, and you can clearly determine the round shape of the expanded beam. So it is not the reason that focus of the lens is to far and the beam size to small. But the projection screen still maintains the direction of the illuminating beam, which I think should not be the case. I assume it is because it is not a collimated beam? Or is the glass bad? Is there an other possibility to get a equally lighted screen. In the result hologram this means that the image is not equally bright from all directions. If you move right or left from center, it gets darker. It's difficult to describe, but I think you understand. So it has to be diffusing, but mine is only partly diffusing and still maintaing a big part of the original direction. Any hints?
Ok i bought a satinized Glass, which Seems to be etched or sandblasted, because it has one rough side. Seems to work, but I have still a question, it's 30x40 cm and I light it with a small lens about 1,5 m away. If you look at the glass there is still a dependency of the angle where you look at in brightness, and you can clearly determine the round shape of the expanded beam. So it is not the reason that focus of the lens is to far and the beam size to small. But the projection screen still maintains the direction of the illuminating beam, which I think should not be the case. I assume it is because it is not a collimated beam? Or is the glass bad? Is there an other possibility to get a equally lighted screen. In the result hologram this means that the image is not equally bright from all directions. If you move right or left from center, it gets darker. It's difficult to describe, but I think you understand. So it has to be diffusing, but mine is only partly diffusing and still maintaing a big part of the original direction. Any hints?