Sony SAL135F28 Service Manual ▷ View online
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SAL135F28 (STF 2.8(T4.5)/135) (135mm F2.8 [T4.5] STF)
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2. Checking of Image
Note:
Check the image of both master lens and checking lens.
1)
Start the Color Calculator 2.
Fig.4-2-3
2)
Read the image from the file menu.
Fig.4-2-4
3)
Set the Color Calculator 2 as follows.
Measured value display (Display menu): RGB+L*a*b*
Measuring method (Display menu):
Center Single Area
Fig.4-2-5
Color space (Edit menu): sRGB
Fig.4-2-6
Area size for calculate (Edit menu
→Option): 256×256 Pixels
Fig.4-2-7
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SAL135F28 (STF 2.8(T4.5)/135) (135mm F2.8 [T4.5] STF)
4)
Click the calculate button to measure the image.
5)
After measuring, check the “G” values.
Average “G” value of the three images shoot with master lens:
(a)
Average “G” value of the three images shoot with checking lens: (b)
Fig.4-2-8
3. Checking Method
1)
Calculate aperture error using the following formula, and check that the aperture error is within the specification.
Aperture error = Average “G” value of checking lens (b) - Average “G” value of master lens (a)
Specification
Aperture error = –20 to +5
2)
When the aperture error is out of specification, perform “4-2-2. Aperture Diameter Adjustment”.
If the specification is met, perform the “4-2-3. M Aperture Diameter Adjustment”.
Calculate button
Check the “G” value
Ver. 1.3 2007.12
The changed portions from
Ver. 1.2 are shown in blue.
Ver. 1.2 are shown in blue.
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SAL135F28 (STF 2.8(T4.5)/135) (135mm F2.8 [T4.5] STF)
4-2-2. Aperture Diameter Adjustment
Equipment
• Adhesive bond (B-10)
Adjustment Method
1)
Remove the 1 group lens block.
Fig.4-2-9
2)
Set the stepless aperture (M aperture) of the checked lens to the fully open state (set the index of the stepless aperture to “A”), and
check that the M iris feathers do not remain in aperture.
3)
Remove the adhesive bond of the three screws fixing the iris retainer tube.
Fig.4-2-10
1 Group Lens Block
A
Aperture Hold Ring
Adjustment Screws
for Aperture Diameter
(Three areas)
for Aperture Diameter
(Three areas)
M Iris Retainer Tube
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SAL135F28 (STF 2.8(T4.5)/135) (135mm F2.8 [T4.5] STF)
4)
Move the preset lever to set the preset ring block at the open aperture position.
Fig.4-2-11
5)
Turn the aperture hold ring to adjust the position where the A iris feathers block are hidden into the edge completely.
Fig.4-2-12
6)
After the adjustment is completed, apply the adhesive bond (B-10) to the head of the three screws as shown in the Fig.4-2-13.
Fig.4-2-13
7)
Assemble the lens completely.
8)
Perform “4-2-1. Aperture Diameter Check”, and repeat “4-2-1. Aperture Diameter Check” and “4-2-2. Aperture Diameter Adjust-
ment” until the aperture error is within the specification.
Aperture Hold Ring
Aperture Hold Ring
Aperture Hold Ring
Apply the Adhesive Bond
(B-10) (Three areas)
(B-10) (Three areas)
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