Sony SAL24F20Z Service Manual ▷ View online
4-4
SAL24F20Z (Distagon 2/24 ZA T * SSM) (Distagon T * 24mm F2 ZA SSM)
4) Click the Calculate button to measure the image.
5) After measuring, check the G values.
Average
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
Fig.
4-2-7
3. Checking Method
1) Calculate aperture error using the following formula, and check that the aperture error is within the specification.
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 = -15 to +10
2) When the aperture error is out of specification, perform 4-2-2. Aperture Diameter Adjustment .
4-2-2. Aperture Diameter Adjustment
Equipment (Only the specific equipment is listed)
Adhesive bond (B-10)
1. Disassemble or assemble the lenses to the state shown in Fig. 4-2-8.
Rear Lens
Assy Block
Assy Block
Rear Lens
Block Holder
Block Holder
Front Lens Assy Block
Focus Ring, Front Barrel
Assy Block
Assy Block
Name Ring
Fig.
4-2-8
•
2. Remove the adhesive bond (three locations) that bonds the hole washer and the rear lens assy block.
Bond (Three locations)
Hole Washer
Rear Lens
Assy Block
Assy Block
Fig.
4-2-9
3. Set the preset ring at the aperture open position by moving the preset lever, and fix the preset ring.
Set the preset lever
to the open of aperture
to the open of aperture
Preset lever
Fig.
4-2-10
4. Turn the hole washer and adjust its position so that the aperture blades just hide behind the inner diameter of the hole washer.
Adjust hole washer position
so that aperture blades
just hide behind the hole
washer inner diameter.
so that aperture blades
just hide behind the hole
washer inner diameter.
Hole Washer
Fig.
4-2-11
4-5
SAL24F20Z (Distagon 2/24 ZA T * SSM) (Distagon T * 24mm F2 ZA SSM)
5. Perform 4-2-1. Aperture Diameter Check and repeat steps 1 to 3 until the aperture tolerance satisfies the specification.
6. After finishing the adjustment, apply the adhesive bond (B-10) to the indicated portions of two screws which are tightened in step 3.
6. After finishing the adjustment, apply the adhesive bond (B-10) to the indicated portions of two screws which are tightened in step 3.
Apply the grease (B-10)
Hole Washer
Rear Lens
Assy Block
Assy Block
Fig.
4-2-12
4-1-2. Adjustment Flow Chart
4-3. PROJECTIVE RESOLVING POWER CHECK/ADJUSTMENT
4-3-1. Projective Resolving Power Check
Setting of Lens Test Projector.
Equipment
Lens Test Projector and Variable Transformer (Output voltage: AC 100 V)
Note:
Note:
Connect the variable transformer (Output voltage: AC 100 V) to the lens test projector.
A-mount Attachment
Screen (Art paper)
Tape Measure
Plane Mirror (For SLRs)
Screen (Art paper)
Tape Measure
Plane Mirror (For SLRs)
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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
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.
(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.
Note:
Be sure to have the right position and direction of the lens.
Lens test projector
Incorporate of the lenses
according to the checking focal-length (f).
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
Fig.
4-3-1
2) Attach the checking lens to the lens test projector, and set the equipment as shown in Fig. 4-3-2.
3) Turn the fan switch of the lens test projector to ON, then turn the lamp switch to ON.
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
Fig.
4-3-2
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
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.
4-6
SAL24F20Z (Distagon 2/24 ZA T * SSM) (Distagon T * 24mm F2 ZA SSM)
2. Projective Resolving Power Checking Method
1) Turn the focus ring of the checking lens until the chart image projected on the screen is the sharpest at the center (y = 0).
2) Read the number of the smallest pitched lines at the center (y = 0).
1) Turn the focus ring of the checking lens until the chart image projected on the screen is the sharpest at the center (y = 0).
2) Read the number of the smallest pitched lines at the center (y = 0).
The number represents for lines per mm.
Sagittal (S)
Meridional (M)
Fig.
4-3-3
3) Rotate the mount rotational plate of the lens projector while observing y = 9, y = 12, y = 15 or y = 18 and stop it at the location where
the projective resolving power is worst (low).
Read the number of the smallest pitched lines (both sagittal and meridional: 3 lines) at the peripheral point.
Note:
Note:
When reading the number of the smallest pitched lines, be careful of the spurious resolution.
Spurious resolution is the reversed image of 2 or 4 lines which appears on screen when focus is beyond maximum revolving power as shown in
Fig. 4-3-4.
Fig. 4-3-4.
Do not confuse spurious resolution for the smallest pitched lines.
Correct resolution
Spurious resolution
Fig.
4-3-4
4) Change the focal length and projected length of the checking lens. (In case of the zoom lens), project the S image and the M image at
each focal point/projected length and confirm that the number of resolution satisfies the specification of the Table 4-3-1.
Specification
Focal length f (mm) Distance (m)
Number of the smallest pitched lines (lines/mm)
Center (y' = 0)
Peripheral (y' = 15)
Peripheral (y' = 18)
S
M
S
M
24
0.96
100 lines or
greater
50 lines or
greater
40 lines or
greater
50 lines or
greater
32 lines or
greater
Table
4-3-1
5) Check the projective resolving power. If the projective resolving power does not satisfy the specification, perform 4-3-2.
Projective Resolving Power Adjustment .
4-3-2. Projective Resolving Power Adjustment
Note:
Check the projective resolving power. If it does not meet the specification, adjust the projective resolving power.
1. Adjustment method (partial defocus adjustment)
1) Check the projective resolving power, and then check partial defocus (front focus tendency and rear focus tendency).
2) Adjust the projective resolving power as follows according to the partial defocus direction.
1) Check the projective resolving power, and then check partial defocus (front focus tendency and rear focus tendency).
2) Adjust the projective resolving power as follows according to the partial defocus direction.
• In the case of front focus tendency, decrease the number of front group adjustment washers on the front focus tendency side.
• In the case of rear focus tendency, increase the number of front group adjustment washers on the rear focus tendency side.
Front Group Adjustment Washer
Parts Number
t (mm)
4-195-118-01
0.03
4-195-118-11
0.04
4-195-118-21
0.05
4-195-118-31
0.1
4-195-118-41
0.2
4-195-118-51
0.3
Table 4-3-2
Fig.
4-3-5
3) Check the projective resolving power.
Repeat steps 1) to 3) until the projective resolving power meets the specification.
4-1-2. Adjustment Flow Chart
4-4. FLANGE BACK (f F) CHECK/ADJUSTMENT
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)
Flange back tester
A-mount attachment
Flange back gauge (43.50 mm)
4-4-1. Flange Back (f F) Check
1. Preparations
1) Set the equipment as shown in the Fig. 4-4-1.
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
Fig.
4-4-1
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Front Group
Adjustment Washer
Adjustment Washer
Front Group
Adjustment Washer
Adjustment Washer
Front Group
Adjustment Washer
Adjustment Washer
Three screws
Front Group
Adjustment Washer
Adjustment Washer
Front Group
Adjustment Washer
Adjustment Washer
Front Group
Adjustment Washer
Adjustment Washer
Three screws
4-7
SAL24F20Z (Distagon 2/24 ZA T * SSM) (Distagon T * 24mm F2 ZA SSM)
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.
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.
Note:
Turn the knob in the direction of the arrow of Fig. 4-4-2 for correct reading.
Focusing knob
Focus on fine lines on the surface.
Always turn the knob in the arrow
direction for correct reading.
direction for correct reading.
Fig.
4-4-2
5) Turn the scale ring of the dial gauge until the long pointer indicates 0 .
Note:
This position is the flange back (f F) = 43.50 mm.
Memorize the position of short-pointer.
2. Checking Method
1) Set the focus to the over-infinity end and confirm that the specification is satisfied.
1) Set the focus to the over-infinity end and confirm that the specification is satisfied.
Specification (Over-infinity end)
Focal length (mm)
Flange back value f F(mm)
24
44.87 - 44.95
Table
4-4-1
2) When the flange back (f F) of the checking lens is out of specification of the Table 4-4-1, perform 4-4-2. Flange Back (f F)
Adjustment .
4-4-2. Flange Back (f F) Adjustment
1. Preparation
1) Perform 4-4-1. Flange Back (f F) Check and confirm that the flange back (f F) does not satisfy the specification in Table 4-4-1.
1) Perform 4-4-1. Flange Back (f F) Check and confirm that the flange back (f F) does not satisfy the specification in Table 4-4-1.
2. Adjusting Method
1) Set the focus to the infinity end.
2) Turn the knob of flange back tester to achieve good focus, read the flange back value (f F).
3) Calculate the amount of increase or decrease of back adjustment washer by the formula below, using the result derived from step 2).
1) Set the focus to the infinity end.
2) Turn the knob of flange back tester to achieve good focus, read the flange back value (f F).
3) Calculate the amount of increase or decrease of back adjustment washer by the formula below, using the result derived from step 2).
Amount of increase or decrease of back adjustment washer = Flange back f F (measured value) at over infinity end - 44.93 mm
In case that the amount of back adjustment washer is negative (-): Decrease thickness of the back adjustment washer.
In case that the amount of back adjustment washer is positive (+): Increase thickness of the back adjustment washer.
Connection
Board
Board
Back Adjustment
Washer
Washer
Rear Light
Interception Tube
Interception Tube
Mount Assy block
Fig.
4-4-3
Back Adjustment Washer
Part No.
Description
4-195-105-01
0.05
4-195-105-11
0.07
4-195-105-21
0.1
4-195-105-31
0.2
4-195-105-41
0.5
4-195-105-51
0.03
4-195-105-61
0.04
Table
4-4-2
4) Adjust by repeating steps 1) to 3) until the flange back satisfies the specification.
4-1-2. Adjustment Flow Chart
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