May 19
th
, 2021
Supra-5000 Digital Cinema and Secured Media Projection System
Installation Manual
- 78 -
9. Optical Correction
9.1 Lens back focus Adjustment
Step 1:
Turn the screen image to the maximum (adjusted by the
ZOOM +
button) and observe the
clarity of the grid in the middle of the screen. If it is not clear, adjust the front focus (adjusted by the
Focus +/-
buttons) to make the line pairs in the center of the screen clear.
Step 2:
Adjust the picture to the minimum (through the
ZOOM -
button) and observe the clarity of the
grid in the middle of the picture. There are two situations at this time:
▪
The clarity of the picture center line pair is consistent with that of the picture at its maximum,
proceed to
Step 3
.
▪
The center grid of the picture becomes blurred. At this time, take a piece of white paper and
judge whether the clear surface of the center grid is in front of the screen or behind the
screen. If it is in front of the screen, loosen the corresponding three screws in the lens
bracket (increase the back focus). If it is behind the screen, tighten the corresponding three
screws in the lens bracket (decrease the back focus), then adjust the picture to the
maximum and repeat
Step 1
.
Figure 59
Step 3:
Observe the clarity of different areas of the picture. If the clarity of the whole picture is
consistent, there is no need to adjust the back focus. If the picture has up and down pitching, adjust
by adjusting
1# and 2# screws
at the same time or adjusting
3# screw
separately. If there is left-right
pitching, adjust it by adjusting
1# and 3# screw
or adjusting
2# screw
separately until the global
picture is clear.
