Sony SAL70200G Service Manual ▷ View online
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SAL70200G (2.8/70-200 G) (70-200mm F2.8 G)
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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.5-2-2
2)
Read the image from the file menu.
Fig.5-2-3
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.5-2-4
Color space (Edit menu): sRGB
Fig.5-2-5
Area size for calculate (Edit menu
→Option): 256×256 Pixels
Fig.5-2-6
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SAL70200G (2.8/70-200 G) (70-200mm F2.8 G)
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.5-2-7
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 master lens (a) - Average “G” value of checking lens (b)
Specification
Aperture error = –25 to +0 (WIDE end: 70mm)
2)
When the aperture error is out of specification, perform “5-2-2. Aperture Diameter Adjustment”.
Calculate button
Check the “G” value
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SAL70200G (2.8/70-200 G) (70-200mm F2.8 G)
5-2-2. Aperture Diameter Adjustment
Equipment
• Adhesive bond (B-10)
• Maxium Aperture Jig
• Universal Wrench
• Chip-A for Universal Wrench
• Chip-B for Universal Wrench
1. Preparation
1)
Disassemble or assemble the checking lens into the state of Fig.5-2-8.
(Remove the parts of forward (object side) from the aperture blade, perform in the condition the lens is seen.)
2)
Install the maximum aperture jig and open the aperture.
Fig.5-2-8
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SAL70200G (2.8/70-200 G) (70-200mm F2.8 G)
2. Adjustment Procedure
1)
Loosen the nine screws that tighten the aperture hold ring.
2)
Open the aperture and rotate the aperture hold ring. then, adjust so that the aperture blades are hidden behind the aperture hold ring.
3)
Tighten the nine screws, apply the adhesive bond (B-10) to three locations (two interval) at A parts (head of screw).
4)
Apply the adhesive bond (B-10) to nine locations at B parts (tip of screw).
Fig.5-2-9
5)
Assemble the lens completely, perform “5-2-1. Aperture Diameter Check”.
Note:
Perform “5-2-2. Aperture Diameter Adjustment” and “5-2-1. Aperture Diameter Check” until the aperture tolerance meets
the specification.
Apply the adhesive bond (B-10)
B parts(Tip of screw)(Nine locations)
Apply the adhesive bond (B-10)
A parts(Head of screw)(Three locations)(Two interval)
Aperture Blade (Nine pieces)
Aperture Hold Ring
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