OK, do you want to project the light into a room? Sunlight or artificial?

What would be the ideal end result? What effect are you trying to achieve?

More info!

This a classic theater lighting design project. (Its been decades since I've done this so please be kind on my use of nomenclature folks. )

First, the light you are projecting will not become visible until it strikes an object or is directed straight into your eye. Now depending on the spectrum of the light and the pigment of the object struck by the light the quality of the light can now be observed. Remember the hue (color) of light add color while the pigment (color) removes color. Now to get what is visually perceived as a transparent color, the spectrum of the of the observed light must include a fairly uniform color distribution of light at a lower intensity than the desired color perceived. In simpler terms, for a transparent blue, there must be perceptible but less brilliant red, green, and yellow light present. This way a pure red ball will appear to be dark red in a transparent blue light, instead of the black ball a pure blue light will produce. So while some gel filters can be found with a transparent spectral response, often the desired combination does not exist. So to create a transparent light when no readily available filter exists, one uses two lights to strike the same surface. One tinted by a less-transparent filter and the other a dimmer white light.

Now to obtain a uniform intensity can be much trickier. For the inverse square law of light intensity cannot be altered. So if the distance the light striking your panels must be dramatically different from top to bottom, then nothing can be done to change the light intensity striking the panels. Your only option is to change the reflective nature of your panel. A creative painter with a paint sprayer can feather in neutral density pigment (grey) from the panel section closest to your lamps to the no added pigment at the farthest.

To create your rectangular shape just use an ellipsoidal projecting lamp (Kleig light) and adjust the internal shutter blades to give the desired shape. Defocussing the lamp will soften your edges.

lastly, your picture implies that your panels will face each other. This will mean that a certain amount of light will bleed from panel A to panel B.

I am trying to create (as best I can describe) something that looks like a room divider except, as opposed to the new pic mine would be of light only without side supports and if a beam is not the correct term then how about rays of light

1" wide x 10' high x as narrow as possible."

These dimensions are of a rectangular prism (ie, a box having the dimensions X•Y•Z), not of a beam as such. Please explain.

I guess I'm not on your page yet, but would like to get there asap, are you saying to project the light through a prism or a box with the light in it?

I always thought that light kind of faded or scattered around the edges as in spot or flood lights etc

I'm on your page! yes that's the word collimated, That is precisely the word.

now if I can form collimated rays of light then at the corners where the colors meet and being for the moment they are rectangles there would be a mixing of the colors or thick corners i.e. twice the thickness of one column , right.

also, if I understand you correctly and the light does not fade or scatter on the edges and, it can be shaped to be rectangular then, there is also the possibility when creating the form through which the light is projected to have alternating 45 deg angles cut off the corner so that the opposing lights can merge together??

Gary

It cannot be light alone. It must be light shining onto a substance. If one introduces a suspended media to the air, like a fog, then the light will appear as a cone of some type striking the suspended particles in air. The apex of this cone will be the light source. If one utilizes a bright enough of a light, like the sun, then one can see the Tyndall effect from moisture in the air outside of the cloud formation blocking the sun. (Technically, how a cloud blocks sunlight itself is from the Tyndall effect.) But to create a color screen room divider, a screen must be present to shine the light onto.

Here's another way to look at this (no pun intended). If light not entering your eye could create an image in your eye, then the light from your ceiling right now would block your vision of your screen and keyboard. Instead the light from the ceiling and computer screen is getting scattered by your hands, and the keyboard to allow some small portion into your eye to make an image. But you cannot see the light as it travels towards your hands.

I hope this helps.

So these panels are fundamentally 'thin slabs of light' - just light and nothing else at all - with no visible means of support? 'Slabs' floating in thin air, as it were?

Is this what you have in mind?

If what is being conceived is a light curtain with bands of different colored light at 45 degree angle the best bet may be to have laser LED units arranged in the desired fashion at roof level pointing vertically down to the floor, which is provided with a transparent stip where the light hits to enable it to pass through and be absorbed onto a black painted gutter below.

The problem is to make the curtain visible some sort of fog will be needed.

Bioramani

"looks like a room divider except, as opposed to the new pic mine would be of light only"

The only means of doing this currently is to use visible beam lasers with a slotted mask, you'll need two of different colors and an arrange of mirrors or a bunch of costly lasers (forget about laser diodes, they only give you visible spot where they incide) The last part of your description tells me you don't want a fog machine for the effect.

Yahalsit

If your wall is physical, backlit plastic strips would work.

If you just want this to appear in clear air (no fog), holographic projection is a possibility, although I suspect your requirements far exceed state of the art.

Of course holographic projection would do it. We'll just fabricate a holodeck with our replicator.

Easier than that though would be to make everyone in the room wear those new 3D glasses and project onto a white wall the images. Of course somebody trying to walk behind the yellow and green curtain would look pretty odd.

(I presume I'm just extending the absurdity of your suggestion. )

redfred: (I presume I'm just extending the absurdity of your suggestion. )

Not entirely absurd as the demo I saw about 30 years ago was quite impressive.

Not sure what the state of the art is, but if money is no object...

The best way is to do rear projection. Use white polycarbonate (if this is a permanent setup as it is strong but $$) but chinese paper would also work; you want white, not clear. Make the screen in a frame and then you can use LED bars (ikea sells some that are ok, but expensive) Incandescent lights will also work, but you'll get bright spots (LEDs are good because they are many little lights, and generate little heat.) You could also use light ropes, but they have a short life time. Make the frame of the wall deep enough that the lights illuminate the whole screen but don't project on the other screens. If you can, enclose the lights completely painting every surface inside the box with a flat white paint.