ROOM DARKENING & OTHER (AMBIENT) LIGHT CONTROL TIPS THAT WILL INCREASE PERCEIVED CONTRAST AND PICTURE DEPTH

People often ask me how much ANSI lumen light a CRT projector can output. When i answer them they start laughing and tell me how their new DLP is able to output 1700 ANSI Lumen of light which of course is so much better. Now this.. is where most people are wrong. You see modern DLP and LCD projectors are being developed for on-the-road use. People use them to hold presentations in boardrooms, hotels, classrooms and god knows where else. Most of these presentations take place in daylight or well.. rooms that have some form of ambient lighting.

Cinema is not about that. When was the last time you were in a movie theater and happily sat through a movie with the lights on? Never of course. Because ambient light washes out picture contrast and results in a grayish image that lacks all punch, detail and clarity. So when we're watching movies, we do it in the dark. And in the dark.. you dont need 2000 ANSI lumen of light. It will only hurt your eyes more.

Contrary to DLP and LCD, CRT technology has a dynamic light output that varies with the lighted surface area size. While full screen white will result in a relatively low amount of light per cm2, small lighting objects, such as a torch or headlight will appear far.. FAR brighter than anything you'll ever see on DLP. In reality even the smallest CRT will output some serious light when used in a properly darkened room.

However, because the lower end of the grayscale is so dependant on controlled room lighting/darkening, any source shedding light on the screen besides the projector itself will result in less contrast. This leads us to a number of interesting tweaks that can do more for your projected image than most of the electronics tweaking on this site.

A - Darken your room
Get some sun-light blocking rolldown curtains or better yet, black velvet drapes and make sure you keep out any sunlight. Turn of any smaller lights when possible. Light automation is very cheap nowadays. A remote control and some r/c light dimmers will set you back about 70 euros.

B - Darken your equipment
If you have a big amp sitting in your home theater, check if you can dim the display panel so it doesnt shed any unwanted light on the screen. Like the exit sign in the cinema.. Even the smallest light can be distracting.

C - Prevent scattered lighting back onto the screen
One of the biggest problems with home theaters is that most people don't like living in black rooms. I can't blame you guys, but the white walls in your room will throw the light coming from the screen, back onto the very same screen surface. This scattered light heavily depends on the materials used on your wall. Matte paint or wallpaper will be far less than mirroring surfaces such as high-gloss paint, lacquered panels or poster frames with reflective surfaces. If you want to see DRAMATIC improvements in contrast, simply hang some drapes on the walls on the sides, closest to your screen. Even a single meter of "black cloth" on the wall can have a huge impact on perceived contrast and colordepth. The same thing goes for your ceiling. A white ceiling will throw light back onto the screen surface. If you take some black cloth that your can attach to four nails in the ceiling or something similar, you will see another dramatic improvement. Of course, the best approach is to paint your HT black or apply dark carpeting everywhere, but personally i'd settle for some curtains that can be redrawn so they become invisible and your HT looks like a normal room when not in use.

D - Add a black (velvet) border around your screen
Your eyes will perceive a dark border around the screen as increased contrast. Colors will appear more vibrant and the sharp separation between background and moving image will draw you more "into the movie". If you mainly watch 16:9 movies, get a 16:9 screen or mount a small retractable black rolldown curtain in front of your 4:3 screen so you can vary screen aspect ratios without ending up with a piece of "unused" white screen surface.

E - Use tube blanking
The Barco 800 has a great option in the menu called Blanking. This allows you to "matte" out unused parts of the tube surface, preventing light from these areas hitting your screen or surrounding areas. Those parts of the tube raster are simply "shut off". Blanking is a great feature to get rid of artifacts outside of the screen area, but inside the raster area. It also allows you to create a cleaner edge around the image surface.

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