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SAL70400G2 (4-5.6/70-400 G SSM Ⅱ) (70-400mm F4-5.6 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. 4-2-1.

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

 

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SAL70400G2 (4-5.6/70-400 G SSM Ⅱ) (70-400mm F4-5.6 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  4-2-2. Aperture Diameter Adjustment .

Equipment
•   Adhesive bond: (B-10)

1. Adjustment Procedure
1)  Remove the rear light shield barrel.
2)  Open the aperture as far as it goes by moving the preset lever and fix the aperture ring at the location where the aperture is open.

Signal Board

Rear Light 
Shield Barrel

Aperture open position

Preset Lever

3)  Loosen two screws a little and move them right and left so that the operating lever of the preset ring can move right and left.
4)  While viewing the light source from the rear lens, move two screws right and left and tighten two screws at the position where the 

blades of aperture are completely hidden by the neighboring frame.

 

Two Screws

Apply the adhesive 
bond (B-10)

5) Perform 4-2-1. Aperture Diameter Check  and repeat steps 1) to 4) until the aperture tolerance satisfies the specification.
6)  After finishing the adjustment, apply the adhesive bond (B-10) to two screws which are tightened in step 4).

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)

1)  Set the equipment as shown in the Fig. 4-3-1.

 

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

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SAL70400G2 (4-5.6/70-400 G SSM Ⅱ) (70-400mm F4-5.6 G SSM Ⅱ)

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 sharpest.
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. 4-3-2 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.

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 observing the microscope.
 

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

4-3-5 (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

 

WIDE end

TELE end

CB

Less than 0.11 mm

Less than 0.15 mm

5)  In case that the CB of checking lens does not satisfy the specification, perform  4-3-2. Optical Axis Adjustment .
6)  In case that the CB of checking lens satisfies the specification, perform  3. Adjustment Method 2 (WIDE end)  of  4-5-2. Focus-shift/

Flange Back (f F) Adjustment .

Check the optical axis. And if the value does not satisfy the specification, perform the optical axis adjustment.

1. Preparation
1) Perform 4-3-1. Optical Axis Check  and confirm that the optical axis of the checking lens does not satisfy the specification.

2.  Adjustment Method 1 (TELE end)
1)  Remove the rear light shield barrel and the light shield ring.
2)  Remove the 6th assy, insert the 6th tilt washer in between the 6th assy and the 6th adjustment washer and adjust.

  Insert the 6th tilt washer in the CB direction.

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SAL70400G2 (4-5.6/70-400 G SSM Ⅱ) (70-400mm F4-5.6 G SSM Ⅱ)

3)  Install the 6th assy and tighten it with three screws.

  •  Return the 6th assy to the original position.

 

•  Tighten the screws, starting with the location where the 6th tilt washer is inserted.

4) Perform 4-3-1. Optical Axis Check . And if the value does not satisfy the specification, repeat steps 2) and 3) again.

Three Screws

Light Shield Ring

6th Assy

6th Tilt Washer

6th Adjustment Washer

Signal Board

Rear Light 
Shield Barrel

Part No.

Thickness t (mm)

4-124-676-01

0.02

4-124-676-11

0.03

4-124-676-21

0.05

3.  Adjustment Method 2 (WIDE end)
1)  Replace the 2-6th assy.
2) Perform 4-3-1. Optical Axis Check  and confirm that the value satisfies the specification.
3)  In case that the value satisfies the specification, perform  4-4-1. Projective Resolving Power Check .

Setting of Lens Test Projector.

Equipment
•  Lens Test Projector and Variable Transformer (Output voltage: AC 100 V)

 The lens test projector is used by connecting the variable transformer (Output voltage: AC 100 V).

• A-mount Attachment
•  Screen (Art paper)
• Tape Measure
•  Plane Mirror (For SLRs)

1. Preparations
1)  Perform the following steps (1) to (3), and incorporate the internal lenses of the lens test projector according to the checking focal 

length.
(1)  Open the lid of the lens test projector.
(2)  Pull up and turn the fixed levers on the right and left sides of the lens test projector.
(3)  Remove or insert the lens.

Be sure to insert in the right position and direction of the lens.  

 

Lens test projector

Incorporate of the lenses
according to the checking focal-length (f).

Lens

Fixed lever

Fixed lever

Lid

f=18 to 35 mm

f=35 to 100 mm

f=100 to 200 mm

f=200 to 300 mm

Heat-absorbing filter 

Chart

Chart

Chart

Chart

Filament

Filament

Filament

Filament

2)  Attach the checking lens to the lens test projector, and set the equipment as shown in Fig. 4-4-2.
3)  Turn the fan switch of the lens test projector to ON, then turn the lamp switch to ON.  

 

Distance

Lens test projector

Chart

Fan switch

Lamp switch

Plane mirror

Screen

A-mount attachment

Checking lens

F

L

4)  Turn the focus ring of the checking lens until the chart image projected on the screen is the sharpest at the center (y  = 0).
5)  Set the plane mirror to the center of the projected image (y  = 0), and adjust the projector position so that the mirror reflects the light to 

the center of the lens.