Theater Design Guidance
Throw Distance and Throw Ratio. The ratio of throw distance to UltraWide screen width should be at least 1.6:1 (1.4:1 for the new Paladin DCR – TDG update coming). Based on this, adjust the gold slider below to your throw distance (projector lens to screen) and the calculator will show you the maximum UltraWide screen size. Any screen smaller than this maximum size is also recommended since it creates a higher throw ratio. Or, adjust the gold slider to your UltraWide screen size and the calculator tool will show you the minimum throw distance. Any throw distance greater than this minimum is also recommended since also creates a higher throw ratio. Using a lens at a throw distance range shown as deep red is not recommended.
Why is throw ratio important? First, a low ratio (ie below 1.6:1) means a more severely expanding beam that might be cut off by the lens which will make corners of the image fade in brightness. Second, projector ECC may not be able to fully compensate for color fringing designed into the Phoenix lens. Third, geometric distortion (“pincushion” with Phoenix, “barrel” with Paladin) is entirely based on the throw ratio. Here’s what to expect at different UltraWide throw ratios:
2.0:1 or higher: Geometric distortion is almost non-existent even at the edges. Phoenix can be used with any projector model with little noticeable color fringing in movies (ECC still generally recommended at all throw ratios).
1.8:1 – 2.0:1: Very minor edge distortion. Uncorrected Phoenix color fringing is more noticeable close to the screen.
1.6:1 – 1.8:1: Edge distortion can be easily masked by the screen border but is still very difficult to see in the image. For reference, at the minimum recommended throw ratio of 1.6:1 a 144″ wide screen will show edge distortion from a lens requiring under 3/4″ of masking from the screen border. Phoenix should only be used with the ECC feature of Sony, Epson, JVC projectors
Below 1.6:1: Even with the edge distortion masked off, distortion starts to be visible toward the perimeter of actual images. Nonetheless, many home theaters have ratios down to about 1.5:1 realizing that some geometric distortion will be visible (ie buildings may not have straight edges at the periphery of the image). It is minor, but still somewhat noticeable, just like the distortion sometimes seen in many films from the camera lenses. Phoenix/ECC may not fully correct color fringing.
Note: the above distortion is only from the anamorphic lens. A curved screen will also add barrel distortion at the top and bottom of the image which will add to any barrel distortion from a Paladin lens or will subtract from any pincushion distortion from Phoenix lens.
Your Screen. An aspect ratio of 2.4:1 is recommended for all new theaters because that is the ratio of most movies since 1971. The older 2.35:1 aspect ratio will be fine although some pixels may need to be masked off to make movies fully fit. The Paladin lens can be adjusted for either aspect ratio for a best fit. The screen should have a deep black border of at least 40mm to mask minor changes in movie aspect ratios, minor setup imperfections and for any residual edge distortions.