Sony G90 User Manual

Page 76

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to accommodate the three lens assemblies and input connec-
tors, and then slopes gently downward toward the rear. There
are no handles or other means for lifting the projector so it
can be quite awkward when lifting to a ceiling mount position.

The three lens assemblies are recessed into the case with

just their rims exposed on the front bezel. The entire top
cover is hinged at the rear and swings open to mechanically
aim and focus the CRT-lens assemblies. All input connectors,
the power switch and line-cord receptacle reside on the front
panel, slightly recessed from the lens bezel. When the projec-
tor is ceiling mounted all of the connectors are above the lens-
es, which keeps cables out of the way. A remote control jack
is provided that can be used with one of two supplied cords
(13’ and 52’) to save batteries during long calibration sessions.

Two IR remotes are provided, one for installation and

another for user operation. The installation remote contains
dedicated keys for almost all calibration functions to avoid
going through the on-screen menus. The remote is backlit for
working in the dark. The smaller user remote runs only on
batteries and is not backlit.

The rear panel contains status lights, a two-digit diagnos-

tic display, and a small collection of keys for navigating the
on-screen menus. The latter need never be used since set-up
and operation is more easily done from the remote control.

Inputs/Outputs

BNC connectors are provided for RGB and sync inputs. Com-
posite or separate H and V sync, as well as sync-on-green can
be used. Composite and S-Video inputs are provided using an
unusual 15-pin D-connector. A short breakout cable is includ-
ed to provide a standard mini-DIN jack for the S-Video and a
BNC jack for composite video. These inputs are compatible
with NTSC, PAL, and SECAM. Curtain control switching is
provided via DC voltages on another D-connector.

There are no YPbPr component video inputs. Line dou-

blers and other video upconverters provide RGB outputs. But
some HDTV set-top boxes provide only YPbPr outputs (Pana-
sonic, Pioneer), while others provide RGB outputs (Sony,
RCA) or both. This is a common limitation of a large installed
based of projectors, so hopefully future set-top boxes will be
designed with both RGB and YPbPr outputs to maximize their
market opportunities.

Installation and Set-up

A professional installer should always be used for mounting
projectors on ceilings. Projectors are heavy, and proper
mounting is a safety and performance issue. Furthermore, a
professional calibrator must be used to do the initial
set-up.

This requires mechanical adjustments inside the pro-

jector where there are lethal voltages that remain present
even when the projector is unplugged,

which again is both

a safety and performance issue.

The projector used for this review was mounted on the

ceiling and an 89-inch wide, 1.85:1 Stewart Filmscreen was
used for display. As with all CRT projectors, the correct dis-
tance and height relative to the screen must be set correctly.
The distance from the screen to the lens for the DTV-930 must
be 1.33 times the screen width when using multi-aspect-ratio
widescreens. Runco has superb technical phone support and
should be consulted to find out the exact height and distance
dimensions you would need for any screen size and one of
their projectors. A professional installer should mount the

projector and do the mechanical adjustments,
which consist of setting two knobs on each lens
assembly for the correct projection angle and
screen size, aiming the CRT-lens assemblies to
converge at center screen, and adjusting focus
rings for best center and edge focus for each
CRT. From that point, all other calibration is performed elec-
tronically using the remote control.

The grayscale color-temperature must always be calibrated

by a professional using a color analyzer. Don’t avoid this step,
and make certain your calibrator has a color analyzer. The
color accuracy of this projector is excellent, but it depends, like
all display devices, on an accurate grayscale adjustment that
can only be done using sophisticated test equipment. The pro-
fessional calibrator should also ensure that all set-up adjust-
ments are individually optimized for multiple aspect ratios and
different sources. This projector is remarkably stable and
touch-ups are required infrequently after an initial burn-in and
calibration period of six months or so.

Built-in test patterns consist of cross-hair, focus, white-

w i n d o w, and multiple cross-hatch and dot patterns. When a
projector has electronic remote-control adjustments for geom-
e t r y, convergence and focus, as this one does, I encourage
enthusiasts to learn to do these adjustments. Part of the fun of
projector ownership can be tweaking the picture to optimize
the image quality. But don’t alter the grayscale adjustments or
you will need a professional to put it right again.

An excellent array of adjustments is provided to optimize

geometry and convergence. Each CRT has tilt, skew, ampli-
tude, linearity, pin-cushion, and keystone adjustments for
both vertical and horizontal axis with separate control over
the top, bottom, left and right picture edges as required. Elec-
tronic focus is included for each CRT with adjustments for
center, top, bottom, left and right sides. But the user should
not readjust the blue focus, which will alter the color balance.
In addition there are astigmatism controls with two-pole
adjustments for 8 different areas of the screen. It is time con-
suming, but with effort you will be rewarded with a fine spot
size uniformly over the entire screen.

I found all the adjustments easy to make and logically

organized. There is also a contextual help button on the
remote control that brings up one or more text screens
describing the function and usage of the current adjustment.
I think many users will be quite comfortable in tweaking these
adjustments to keep the alignment in pristine condition.
There is even a function that automatically guides a novice
user through the calibration adjustments in order, a step at a
time. Once all parameters are adjusted for best performance
the point convergence option is remarkably quick and easy to
use. By moving a cursor on a 16x13 grid you can adjust for vir-
tually perfect convergence over the entire screen, which is
always critical for the best picture, but crucial for HDTV. Be
sure you get the point convergence option.

Operating Functions

This is one of the easiest projectors to use. There are 100
video memories that store individual picture formats includ-
ing the input source and all display parameters. Each memo-
ry includes the source scan-rate, display aspect-ratio, and a
complete set of calibration values for that picture format.
Each memory can be individually named by the user, such as
“16.9 DVD” with up to eight characters. The first 10 picture

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