Throw Ratio and Calculate the Projector’s Distance

by projectorinfo / January 24th, 2010

Throw ratio is the stretch (D) from the shade which the projector needs to be in sequence to emanate the specified stretch image. Or the projector’s chuck ratio is tangible as the stretch (D), totalled from lens to screen, which the projector is placed from the screen, widely separated by the breadth (W) of the picture which it will plan (D/W).

Each projector manufacturer has the preference of which sort of lens to place upon their projectors and, understandably, any lens has the opposite set of characteristics. One of the some-more critical characteristics of the lens is the chuck ratio. With chuck comparative measure we can work out the stretch from projector to shade as well as stretch of shade which used.

The ratio, similar to any ratio, is dimensionless. For example, if D equals 10 feet as well as W equals 5 feet, afterwards 10 feet widely separated by 5 feet equals 2. The dimension of “feet” is thereby cancelled out. So, in meaningful this formula, the projector’s chuck comparative measure will yield we with all of the report you’ll need to set up the room. The following examples will improved insist how this works.

Example 1: You know what shade stretch we want, though need to know how distant behind the projector will need to be placed. If the shade breadth is 7 feet as well as the projector’s chuck comparative measure is 2.0 – 2.4:1 (because projectors have wizz lenses, they additionally have the operation of chuck ratios) afterwards we can place your projector anywhere from fourteen to 16.8 feet divided from the screen. (7 * 2 as well as 7 * 2.4 = 14-16.8)

Example 2: Maybe we do not know which shade stretch want, though we do know which the space accessible in your room for projector chain is limited. The projector should be placed fifteen feet divided from the screen. So, how large of the shade can we use? If your projector has the chuck comparative measure of 1.8 – 2.22:1, your shade can be in between 6.76 as well as 8.33 feet wide. (15 / 2.22 as well as fifteen / 1.8 = 6.76 as well as 8.33)