Creating images, logos or text in light is different than using other signs. Several factors can affect the degree of success: light sources, ambient and competing light, reflectivity and color of the projection surface, distance of the surface from the light source, size of the image, color filters, and finally, special effects you may wish to use.

Light Sources -The lamps used in DERKSEN^® projection systems vary by model. Generally, lamps with higher wattage produce more light. Output is rated in lumen. Lamps used in DERKSEN^® units have a light output ranging from 2,600 to 110,000 lumen. Color temperatures also affect how brilliant a projected image is. Color temperatures are rated in degrees Kelvin. Lamps with a higher color temperature produce whiter light. Available color temperatures range from 3,200° Kelvin (a warmer Halogen light) to 5,600° Kelvin (a medium source daylight).

Ambient and competing light - Light is always in competition with other light. There is no light stronger than the sun. Projecting images in light on surfaces that are exposed to daylight is ineffective. A good rule of thumb: the lower the ambient and competing light, the more brilliant and striking the projected images are. But even in areas of high ambient light it is possible to achieve high contrast, as long as the projection surface itself is shielded from competing light.

Reflectivity, color and texture of the projection surface - The optimum surface to project images on is a light colored, matte surface. Darker surfaces (black, dark red or dark blue) are likely to absorb much of the light and will, therefore, be less effective. Sometimes, darker paints have special reflective qualities and may be suitable to project images on. The best way is to check how well the beam of a flashlight is visible on the surface under actual lighting conditions. Generally, matte or textured surfaces produce better results than shiny surfaces. Certain building materials are particularly suitable to project images on: plaster, painted walls, concrete and aggregate, brushed metals, brick, and light wood. Glass, mirrors and certain high gloss metals are less suitable.

Distance of the surface from the light source - The shorter the distance, the brighter the image. It is, therefore, important to select a system with sufficient power to project the image over the desired distance. The DERKSEN^® GL100-GraphicSpot, a small unit, is suitable for distances of up to 3 meters (9 feet), depending, of course, on the ambient light. In near darkness, this system can project much further. This unit uses Halogen lamps and produces a 'warm' light with a color temperature of 3200° K. The GL150-Marathon is capable of projecting images up to 6 meters (20') away at a color temperature of 4000° K. For distances greater than 6 meters or where the ambient light is relatively strong, the GL200MSD (medium source daylight), the GL700MSD or GL1200MSI are better suited. These are based on powerful metal halide technology. They produce a more brilliant, whiter light with a color temperature of 5600° K. The higher the color temperature of the light source, the whiter the image is.

Size of the image - Tradeoffs: the smaller the image, the stronger its intensity. Basically, you trade off brightness for size. Under difficult circumstances, powerful special lenses can be used. A wide angle lens, for example can project an image as high and as wide as the unit is from the projection surface. Example: A unit mounted only 2 meters (6') from the projection surface can project an image 2 meters high or wide. In cases where the unit must be mounted far from the projection surface, a telephoto or zoom lens can be deployed to compensate for the greater distance.

Color Filters - All color filters absorb light, some more than others. As a rule, red and blue filters absorb more light than green or yellow. When using color filters, you trade color for brightness, although images projected with green or yellow dichroic filters can be quite brilliant.

Special Effects - These accessories can be used to set images in motion (horizontal, vertical, circular or elliptical); to fade images and make them reappear; or to create special effects such as rotating images, realistic images of water or clouds; images 'flowing in the wind' or multiple images created from a single one, using a two or four-fold prism. To use these special effects, please contact a DERKSEN^® Lighting Consultant..