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5-3

SAL70200G2 (2.8/70-200 G SSM Ⅱ) (70-200mm F2.8 G SSM II)

Equipment
• Luminance Box
•  Camera (One of DSLR-A700, SLT-A37/A57/A58/A65/A77/A99)
•  AE Master Lens
• Memory Card
•  Personal Computer (Color Calculator 2 installed)

  Confirm the checking lens by complete.

1)  Install the memory card to the camera.
2)  Set the equipment, camera and AE master lens as shown in Fig. 5-2-1.

Luminance box
 Luminance: EV12

Camera
 ISO: 100
 Exposure Mode: M
 Shutter Speed: 1/125
 Aperture: F5.6
 Focus Mode: MF
 Metering: Center weighted
 Preset white balance: Tungsten
 D-R: OFF

Master lens or checking lens
 Zoom: Wide end (focal length: 70 mm)
 Focus: Infinity end

Shoot the center of the luminance surface

3)  Shoot the images under the following conditions and save them.

Shoot the center of the luminance surface three times with the AE master lens and checking lens.

Luminance:

EV12

Zoom:

WIDE end (focal length: 70 mm)

Focus:

Infinity end

ISO:

100

Exposure Mode:

M

Shutter Speed:

1/125

Aperture:

F5.6

Focus Mode:

MF

Metering:

Center weighted

Preset white balance:

Tungsten

D-R:

OFF

Check the image of both AE master lens and checking lens.

1)  Start the Color Calculator 2.

 

2)  Read the image from the file menu.

⇒

3)  Set the Color Calculator 2 as follows.
 

Measured value display (Display menu):  RGB+L*a*b*

 

Measuring method (Display menu): 

Center Single Area

 

 

Color space (Edit menu): sRGB

 

 

Area size for calculate (Edit menu 

→

Option): 256

×

256 Pixels

 

5-4

SAL70200G2 (2.8/70-200 G SSM Ⅱ) (70-200mm F2.8 G SSM II)

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)

 

Calculate button

Check the “G” value

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) 

 

Aperture error = -25 to +0 (WIDE end: 70 mm)

2)  When the aperture error is out of specification, perform  5-2-2. Aperture Diameter Adjustment .

Equipment
•   Adhesive bond (B-10)
•   Maximum Aperture jig
•  

Universal Wrench

•   Chip-A for Universal Wrench
•   Chip-B for Universal Wrench
•   Chip-C for Universal Wrench

1. Procedure
1)  Disassemble or assemble the lens as shown in 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.

 

5-5

SAL70200G2 (2.8/70-200 G SSM Ⅱ) (70-200mm F2.8 G SSM II)

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).

 

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

5)  Assemble the lens completely, perform  5-2-1. Aperture Diameter Check .

 Perform 5-2-2. Aperture Diameter Adjustment  and  5-2-1. Aperture Diameter Check  until the aperture tolerance meets the specification.

Setting of the Flange Back (f F) measuring instrument.

Equipment
•  1000 mm Collimator
•  Flange Back Tester
• A-mount Attachment
•  Flange Back Gauge (43.50 mm)
•  Adhesive bond (B-10)

1)  Set the equipment as shown in the Fig. 5-3-1.

 

Flange back gauge (43.50 mm)

A-mount attachment

Objective lens (10x)

Dial Gauge (Min. scale: 0.01 mm)

Scale ring

Eyepiece lens (7x)

Eyepiece ring

2)  Looking through the eyepiece lens, turn the eyepiece ring of the flange back tester so that cross line or scale in the view is the sharp-

est.

3)  Attach the flange back gauge (43.50 mm) securely to the A-mount attachment and hold them together.
4)  Turn the focusing knob of the flange back tester so that fine scratches on the flange back gauge (43.50 mm) is the sharpest.

Turn the knob in the direction of the arrow of Fig. 5-3-2 for correct reading.

 

Focusing knob

Focus on fine lines on the surface.

Always turn the knob in the arrow
direction for correct reading.

5)  Turn the scale ring of the dial gauge until the long pointer indicates  0 .

This position is the flange back (f F) = 43.50 mm.

 

Memorize the position of short-pointer.

5-6

SAL70200G2 (2.8/70-200 G SSM Ⅱ) (70-200mm F2.8 G SSM II)

1)  Attach the checking lens to the flange back tester, and set the 1000 mm collimator.

 

1000 mm collimator

Checking lens

2)  Set the focus ring of the checking lens to 

∞

 (infinity) index or near 

∞

 (infinity)  and adjust the optical axis, observing the microscope 

so that the chart can be seen in the center.

3)  Turn the focusing knob of the flange back tester until the chart image comes into focus.
 

Also check the optical axis aligns with the chart center. (Refer to Fig. 5-3-4.)
Note: 

Figure shows example. The cause depends on individual lens.

 

Optical Alignment
Best alignment

Incorrect aligned
e.g. As the focusing knob is turned, the chart may appear blurry as illustrated.
The cause depends on individual lens.

4)  Perform Step (1) through Step (6) and ensure that the AS and CB values are within specifications. 

  If the specification is  CB  only, steps 1 to 3 are not required.

 AS 

(astigmatism)

 

The phenomenon where the flare on the ring chart appears in a cruciform shape with the ring chart in the sharpest focus. (Fig. 5-3-5 (a))

(1)  Turn the focusing knob until the flare becomes minimum between two approximately opposite points on the ring chart edge (as 

shown with the arrows in Fig. 5-3-5 (b)), and then read the dial gauge value. <A>

(2)  Turn the focusing knob until the flare becomes minimum between two points with the phase of the flare rotated by 90 degrees 

from the above condition (as shown with two arrows in Fig. 5-3-5 (c)), and then read the dial gauge value. <B>

(3)  Calculate the AS value (absolute difference between <A> and <B>) and ensure that it is within specifications.
 

AS value = <A> - <B>

 

CB (Center Blur)

 

The phenomenon where the flare on the ring chart trails in one direction with the ring chart in the sharpest focus. (Fig. 5-3-5 (d))

(4)  Turn the focusing knob until the ring chart edge in the direction of the maximum flare is in the sharpest focus (as shown with 

the arrow in Fig. 5-3-5 (e)), and then read the dial gauge value. <C>

(5)  Turn the focusing knob until the ring chart edge, opposite 180 degrees from the above condition (as shown with the arrow in Fig. 

5-3-5 (f)) is in focus, and then read the dial gauge value. <D>

(6)  Calculate the CB value (absolute difference between <C> and <D>) and ensure that it is within specifications.
 

CB value = <C> - <D>

 

(1)

(1)

(2)

(2)

(5)

(4)

AS

E

D

F

H

G

I

CB

CB

Less than 0.07 mm

Less than 0.1 mm

AS

Less than 0.07 mm

Less than 0.07 mm

5)  If the specifications of CB and AS are not satisfied, perform the  5-3-2. Optical Axis Adjustment .
6)  When their values meet the specification, perform  5-5. FOCUS-SHIFT/FLANGE BACK (f F) CHECK/ADJUSTMENT .

1)  Push the 1 group ball frame tube block to reduce the gap or play.

a.  While observing the collimator, confirm the direction where the CB occurs.
b.  Push the 1 group ball frame tube block in the direction of CB.
c.  Observe the collimator again and confirm the optical axis.

 

G1 Holding Rubber

1 Group Ball Frame Tube Block

G1 Holder Ring