As strange as it may seem, yes, a projector will work through glass. Since there are glass hushboxes where you can put your projector while your project, to reduce noise, then projecting through glass should not be a bad idea.
Although projecting through glass is not the ideal method of projection, there are several reasons why you may want to do so. One reason is to reduce noise interference when projecting from one room into another room.
Suppose you have your projector in one room, and you project images through a hole into another room where you have your screen, and other accessories, covering the hole with glass will keep off the noise from the projector room. It will also keep the cables out of sight.
But whatever reason you may have for wanting to project through the glass, you should take note of these factors before purchasing a piece of glass or projecting on the one you already have.
How to choose the glass for your projection
How thick is the glass?
Thick or thin glasses can work, but thicker glasses work better. You can use a float glass for a thick glass, and a sheet glass if you prefer the thin ones.
However, the float glass is better because the sheet glass can cause the projected image to be discolored.
You can check for this discoloration by looking into the glass from the edge, or shining a very bright light through it, in the dark. Also, avoid coated or beveled glasses as these won’t give you a very good image.
The type of glass
Although different glasses will work well for this purpose, Optical glass is recommended. It gives a clear image, and in fact, makes the image look brighter and better.
However, this glass is more expensive than float glass, but considering its superb effect on image quality, and the fact that you can have a crystal clear image, this glass is worth it.
For a transparent glass, you will need a film; the transmittance of the glass is high, and for this reason, the light from the projector can easily pass through the transparent glass.
The glass must be clean
Every particle of dirt on the glass must be cleaned off before you install the glass screen; dust, tiny particles, finger lines, all must be cleaned. If the dirt is not removed it may affect the projected image.
Cleaning the glass is of greater importance if you will be installing a projector film. A projector film sticks to the glass so they are mounted as one entity. Any particle that gets trapped in between the film and the glass will affect whatever is being projected.
To avoid this, gently wipe the glass surface with a glass cleaner and a clean napkin. Do this until all particles are gone, then you are ready to install the glass screen.
Can you project through a window?
You can project through a window if you are unable to get your hands on any of those recommended glass types. Here is a cheaper alternative that you can use to project on almost any glass, especially your window.
How to do it
Grab a pack of buttermilk, a paint roller, a tray, and of course, your projector. Make sure your window is clean; if there is any dirt or particle on it, wipe it off with a napkin.
Use a tape to square out the portion of the window where you wish to project on. Pour some buttermilk into the tray and take some of it with the paint roller.
Gently roll the buttermilk on the area that you have marked out on the window; paint it in an up and down motion.
Once you have covered the entire area, remove the tapes and leave the surface to dry. Once it is dried, you can project through the glass. This method is similar to painting a screen on the wall.
The difference, however, is that in this method, you are only trying to reduce the transparency of the glass, unlike when painting a projector screen on the wall which will require that you cover-up the entire surface with the paint.
Know that, this procedure may not give you the best image ever, but it works.
How do you project on a glass screen
Now, if you have gotten the right glass screen for your projector, it’s time to start projecting. In this section, you will find the steps needed for you to project on a transparent glass.
Do not worry about the image quality, it will not be affected; rather what you will get is a clear and bright image on the glass.
For this process you need:
- A projector, preferably one with a decent lumen, and that can give a reasonably bright image. The projector should also have a good contrast ratio.
- A squared piece of glass
- A projector film: this will prevent the light from the projector, from passing through the transparent glass.
- Two magnetic tripod mounts: one of the mounts will be used to hold the glass up and the other to hold the projector.
How to do it
Place the glass on a clean and smooth surface, then place projector film on it. The glass and the projector film should be of the same size, and you should avoid creating bubbles when placing the film on the glass as this can affect your image.
After the glass and the film are in place, attach the magnetic tripod mount on one end of the glass. For a small-sized glass, one magnetic tripod mount should do, but if the glass is large, you can use two; one at each end, on one side of the glass.
Fix your projector on the second tripod mount, and place it at an appropriate distance from the glass screen. Turn on the projector and focus the image on the screen. After projecting the image on the screen, you will notice these:
- The image is not very bright in front but is clearer when viewed from the back.
- The image appears flipped when viewed from the back.
To correct this, you need to view the image from the bright side (rear view), and since the image appears flipped, you will have to correct that from the projector’s settings.
Click on settings, then select ‘Projector settings’. From the options, select ‘mode’ and then ‘rotate rear’. This automatically flipped the image around, and you have a perfect image on the screen.
Projecting through glass may sound weird but there is nothing wrong with trying out new things, right?
By comparison, one can say that there is only but a little difference between the image formed on a glass screen and that which is formed on a regular screen.
When projecting through a glass, you want to avoid internal reflections and scattering because these will affect the contrast, sharpness, as well as brightness of the image.
Be reminded that to get the best result, you need the right type of glass. So, before choosing a projection glass, consider the factors which have been earlier discussed in this article. It will help you make a good choice.