The lens throw describes the size relationship between the projector and the projected image. There are three common ways of describing the lens throw
Throw Distance - the distance between the projector lens and the projected image
Throw Ratio - the ratio of the throw distance to the projected image width
Throw Range - the minimum and maximum Throw Ratios of the projector lens
In most cases, the goal is to project an image of a known size. Projector lenses describe the throw range and you need to be able to convert this into the expected image size. If not done correctly the image can be the wrong size or the projector may not work from the planned location.
Throw Ratio Too Low
Throw Ratio Too High
Lens Throw Distance is simply the distance from the projector lens to the projected image
In the image, the throw distance is 6.12m.
The lens throw ratio is the ratio of the lens throw distance to projected image width.
Example 1 - Calculating Throw Ratio from Throw Distance and Image Width
Throw Ratio (TR)
Throw Distance (TD) = 4.76m
Image Width (IW) = 2.8m
TR = TD:IW
TR = 4.76 : 2.8
TR = 1.7 : 1 (simply 4.76/2.8)
{"one"=>"Select 2 or 3 items to compare", "other"=>"{{ count }} of 3 items selected"}
