Choosing The Projection Lens; Method One: Using The Lens Charts - NEC iS15-2K User Manual

2. Installation

Choosing the projection lens

A number of lenses are available for use with the projector. Which lens you choose
will depend on the screen size, image aspect ratio and projection distance.
If the mix of images to be displayed includes images of varying aspect ratio, then
you should base your choice of lens on the widest image that is to be projected.

Method one: using the lens charts

For the image sizes listed below, use one of the charts on the following pages, to
choose a lens.
full width images, including:
native resolution 2048 x 1080 pixels
2.35:1 full width 2048 x 871 pixels
If the image does not fill the full width of the DMD, this effectively increases the
throw ratio of the lens. This can be corrected for by applying a Throw Ratio Factor.
A Throw Ratio Factor (TRF) has been applied to the following charts:
1.85:1 full height 1998 x 1080 pixels
16:9 full height 1920 x 1080 pixels
1.66:1 full height 1793 x 1080 pixels
4:3 full height 1440 x 1080 pixels
5:4 full height 1350 x 1080 pixels
Method two: by calculation
See the calculations, on the page immediately following the lens charts.
iS15-2K
page 2.6
Cinema Projector: User Manual
Notes
For more information about how
to fit and adjust the projection
lens, see Fitting the projection
lens, later in this section.
For more information about how
to determine the image size in
pixels, see Fitting the image to
the DMD, earlier in this section.
For more information about
Throw ratio factor (TRF), see
Useful lens calculations, later
in this section.
This projector does not perform
any image processing on
signals connected to the DVI-D
inputs - an external image
processor such as the MMS
1000 is recommended for this
purpose.
If the anamorphic lens is being
used, then the images will be
projected with a 1.25x increase
in width. This can be corrected
by scaling the signal using an
external image processor.