How Distance Can Affect Projector Brightness
One important specification that buyers should take into consideration when buying portable digital projectors is the brightness of the machine, given in lumens. The higher the lumens, the better your projector will be able to project a clear sharp image even in less than optimally dark rooms.
One factor that’s not so obvious and that’s not stated directly by digital projector manufacturers is that, depending on where your projector is set up from the screen, the brightness level can vary by 200%!
This is an especially important factor to consider for those looking for portable digital projectors since the screen to projector distance will most likely vary from setup to setup.
The goal of this article is to inform you of the impact of your projector’s positioning and lens type on brightness. By understanding how these factors work together, you’ll be able to achieve optimal levels of brightness as given by the projector’s manufacturer.
First off, the brightness given off varies greatly by the lens mode. When in full wide angle mode, the amount of light that makes it out of the lens is maximized and the amount of light is decreased by telephoto mode. In other words, you’ll get more lumens if you place your projector closer rather than farther away from your screen.
With most projectors that have a limited zoom lens, brightness is not an issue, but with certain types of portable digital projectors such as 3LCD and LCoS types which have a zoom ratio of around 2:1, the projector’s position can greatly affect image quality.
While having a large zoom ratio gives you more freedom in where to place your projector the trade off is a dramatic drop in brightness as distance increases. Also, placing your projector closer to the screen to increase brightness will only work up to a point. Too close, anywhere past the zoom mid range and you’ll run into color and image distortion as well as limiting the viewing area for your audience.
This is one important trade off to consider and keep in mind when shopping for portable digital projectors. The amount of brightness you’ll get in real life will likely be less than as stated by the manufacturer and you should look for as high a brightness level as possible to compensate for this.