Gamma Correction Adjustment - Sony BVP-550 Maintenance Manual

4-3-15. Gamma Correction Adjustment

Equipment : Waveform monitor, Vectorscope
Test Point
: TEST OUT connector
Object : Grayscale chart
Preparations:
• Connect the waveform monitor to the TEST OUT
connector.
• Connect the vectorscope to the PIX OUT terminal on the
waveform monitor.
• Shoot the grayscale chart so that the chart frame is
aligned with the underscanned monitor frame.
• RGB/ENC switch (on the side panel) → ENC
• Set the DISP switch (on the side panel) to MENU while
holding down the MENU SEL switch (on the front
panel). Set the menu as follows.
MENU : Paint
PAGE : Gamma (P5)
: Gamma → On
ITEM
PAGE : Knee/W.Clip (P6)
: Knee → Off
ITEM
: A = 100 ±2 IRE (for NTSC)
Iris of the lens
A = 700 ±14 mV (for PAL)
Adjustment Procedures:
1. Set the RGB/ENC switch (on the side panel) to RGB.
Set the R/G/B switch (on the side panel) to G.
2. Set the menu as follows, and adjust the gamma
correction for (M) by using the MENU SEL switch.
PAGE : Video Level (P1)
ITEM : Gamma [M]
Specifications: B = 55.5 ±2.0 IRE (for NTSC)
B = 420 ±14 mV (for PAL)
(Waveform Monitor)
BVP-550
3. Set the menu as follows.
MENU : Paint
PAGE : Video Level (P1)
: Test → 1
ITEM
4. Set the RGB/ENC switch (on the side panel) to ENC.
5. Adjust the auto white balance.
WHT BAL switch (on the side panel) → A
AUTO W/B BAL switch (on the front panl) → WHT
6. Set the menu as follows, and adjust the gamma
correction for (R) by using the MENU SEL switch.
MENU : Paint
PAGE : Video Level (P1)
ITEM : Gamma [R]
Specifications: Center the beam spot on the
vectorscope.
7. Set the menu as follows, and adjust the gamma
correction for (B) by using the MENU SEL switch.
MENU : Paint
PAGE : Video Level (P1)
ITEM : Gamma [B]
Specifications: Center the beam spot on the
vectorscope.
8. Repeat the steps 6 and 7 alternately, until the beam
spot is minimized on the vectorscope.
R
Y
L
G
(For NTSC)
R
Y
L
G
(For PAL)
(Vectorscope)
4-3. Overall Electrical Alignment
4-3-15. Gamma Correction Adjustment
M
G
B
C
Y
M
G
B
C
Y
4-39 (E)