Contrast ratio

Measures the difference between the brightest whites and blacks darker that can display a screen. The higher the contrast ratio, the greater the ability of a display to show subtle color details and tolerate ambient light in the room. The contrast ratio is an important specification for all types of TV screen, but especially for front projectors.

Associated with LCD, Plasma, and projection television displays as well as computer monitors, contrast ratio has become a significant aspect of any display. The contrast ratio can also be thought of as the number of gray shades between full white and full black. Essentially, the higher contrast on a projector increases the perception of depth in the image, and means subtle colour variations show up more clearly. Hence subtle textures are more visible. It also means that dark scenes can cope with more ambient light in the room.

Most projectors are rated in the 300/3000 to 1 contrast ratio, that is to say the blacks are 300 times darker than the white (on a 300:1 model), this means that true black may appear as grayish.

Typically, you want to purchase a projector or flat-panel TV with a high contrast ratio. Below are examples of different contrast ratio's.

Low Contrast:

When contrast is low, images appear washed out. Parts of the image may become difficult to see clearly. Projectors with contrast ratios of less than 500:1 typically provide low contrast. Average contrast ratio in a commercial movie theater is 150:1

Medium Contrast:

When a projector provides good contrast, images are clear and attractive. Projectors with contrast ratios ranging from 500:1 to 1200:1 typically provide medium contrast. Lights off commercial movie theater contrast would be around 350 to 400:1

High Contrast:

With high contrast, images are ultra crisp with vibrant colors. Projectors with contrast ratios exceeding 1200:1 typically provide high contrast. DLP TM (DDR) technology projectors currently offer these high contrast ratios. The highest, true contrast ratio Jeff Paiva has ever measured was just over 400:1 and the image looked holographic from all the detail revealed.