What is grayscale tracking?
The color balance of the projector at various light intensity levels determines the quality of what is called ‘grayscale tracking’. The idea is that black, white, and all shades of gray, should have the correct ratio of the three primary colors used in video projection, Red, Green and Blue.

Projector meant for HT usage, typically make white by shining just the right proportion of red green and blue light on the screen. Ideally shades of gray should have the same proportion of red, green and blue as white, but less of each color. What’s important is that this RGB ratio be the ‘corect’ ratio, and that this ratio remains constant as the intensity of the light in the image changes. This ability for the color balance to track properly with the different levels of light intensity is therefore what is called ‘grayscale tracking’.

Why is this so important? Well, imagine watching a black and white movie on your color projector. Ideally whites should look white, blacks should look black and all the shades of gray should look, well gray. If the projector in the darker part of the image, used too much green, the shadows would seem a bit greenish, and that would be distracting. If the highlights looked yellow, that would also be distracting. So, it is important that all light intensity levels of ‘gray’ have the same ratio of all three colors to achieve a good black and white image on a color projector. Grayscale tracking is also important with color images, as one does not want the color of an object to change as the level of illumination changes, or is in a shadow. Good grayscale tracking, however,requires careful calibration – typically beyond that done by the manufacturer or easily done by a user without test equipment. That is where SMART III comes in.