Αλλο το zoom ratio, κι αλλο το throw ratio, το οποιο κι αυτο εχει καποιο range αναλογα με το zoom του φακου.
Ετσι, ο Χ10 εχει throw ratio 1,85-2,22 που σημαινει οτι καλυπτει την παρουσα αναγκη για throw ratio 2,17 (5,20 αποσταση / 2,40 πλατος οθονης)
http://www.projectorcentral.com/InFocus-X10-projection-calculator-pro.htm
Και απο ενα αρθρο, συγνωμη αλλα το παραθετω αυτουσιο, χωρις μεταφραση και χωρις εικονες. (ωστοσο βγαινει νοημα)
"A projector's throw ratio is defined as the distance (D), measured from lens to screen, that a projector is placed from the screen, divided by the width (W) of the image that it will project (D/W).
The ratio, like any ratio, is dimensionless. For example, if D equals 10 feet and W equals 5 feet, then 10 feet divided by 5 feet equals 2. The dimension of "feet" is thereby cancelled out.
So, in knowing this formula, a projector's throw ratio will provide you with all of the information you'll need to set up a room. The following examples will better explain how this works.
Example 1: You know what screen size you want, but need to know how far back the projector will need to be placed.
If the screen width is 7 feet and the projector's throw ratio is 2.0 - 2.4:1 (because projectors have zoom lenses, they also have a range of throw ratios) then you can place your projector anywhere from 14 to 16.8 feet away from the screen. (7 * 2 and 7 * 2.4 = 14-16.8)
Example 2: Maybe you don't know which screen size want, but you do know that the space available in your room for projector placement is limited.
The projector should be placed 15 feet away from the screen. So, how big of a screen can you use? If your projector has a throw ratio of 1.8 - 2.22:1, your screen can be between 6.76 and 8.33 feet wide. (15 / 2.22 and 15 / 1.8 = 6.76 and 8.33)
Viewing distance (V) is defined as the distance between your audience and the screen. A viewing ratio is V/W or the viewing distance divided by the width (W) of the screen."
Τελικα, ξερει καποιος, μπορουμε να δουμε στημενους αυτους τους 3 προβολεις? Μακαρι και τους 3 μαζι η ξεχωριστα.