16 April 2013 by Shifali Rao
Contrast ratio of a projector is the difference between the deepest black and the purest white it can project and the larger and the higher this ratio is the more detailed the picture quality.
Today, most manufactures have two standard methods to calculate contrast ratios of projectors: ANSI and Full on/Full off. ANSI contrast ratio is obtained by using a checkerboard of 8 white and 8 black rectangles. The contrast is got by measuring the average light output of all the white checks against the average light output of all the black ones. The ANSI values take into account realistic settings of a room and allow for some ambient light in the readings. The Full on/ Full off method gives ratios much higher than ANSI for the same projector as it is measured in an idealistic setting. This can hardly be applicable to your room.
This is why you see highly varying values like 2500:1 and 2,000,000:1 these days. 2500:1 would be the ANSI value which is what we advise you to go by.
Furthermore the thing about contrast ratios is that even the difference between 1000:1 and 2500:1 will hardly be noticeable if the room has even dim lighting . Ambient light prevents the effect of contrast from being discernible, so 2500:1 is a great ratio to have even for home cinema and movie buffs where the projector is placed in a moderate to dark room.
This list of the best projectors is limited to the top rated projectors which have a contrast of 2500:1.