SELP1650 (E 3.5-5.6/PZ 16-50 OSS) (E PZ 16-50mm F3.5-5.6 OSS)
4-6
4-2-2. Optical Axis Check
1. Turn the focus ring to the
∞
direction so that the focus of the checking lens becomes
∞
. And adjust the optical axis while observing the microscope
until the chart image can be seen in the center.
2. Perform Step (1) through Step (6) and ensure that the AS and CB values are within specifications.
AS
(Astigmatism):
The phenomenon where the flare on the ring chart appears in a cruciform shape with the ring chart in the sharpest focus. (The figure below (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 the figure below (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 the figure below (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 the specification.
AS value = <A> - <B>
(1)
(1)
(2)
(2)
AS
E
D
F
CB (Center Blur):
The phenomenon where the flare on the ring chart trails in one direction with the ring chart in the sharpest focus. (The figure below (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
the figure below (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 the figure
below (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 the specification.
CB value = <C> - <D>
(5)
(4)
H
G
I
CB
Specification (Reference)
CB (Center Blur)
WIDE End
CB (Center Blur)
TELE End
AS (Astigmatism)
WIDE End
AS (Astigmatism)
TELE End
0.09 mm or less
0.15 mm or less
0.06 mm or less
0.10 mm or less
3. If the specifications are not satisfied, replace parts in the order shown below.
(1) Replace the 1 Group Block Assy
(2) Replace the 2 Group Block Assy
Note:
If it cannot be resolved even after replacing the 1 Group Block Assy and 2 Group Block Assy, replace the Service Exclusive Optics Block.
4-3. RESOLVING POWER CHECK
4-3-1. Setting/Preparation of the Lens Test Projector (F)
Preparations of Using a Camera (General E-mount Interchangeable Lens Digital Camera)
Equipment and Tools
• Lens Test Projector (F)
• Screen
• Tape measure
• Plane mirror (For SLRs)
• Camera (General E-mount Interchangeable Lens Digital Camera)
• E-mount extension jig
• E-mount APSC jig for lens test projector (F)
• E-mount attachment
Note:
Attach the E-mount APSC jig for Lens Test Projector (F) and the E-mount attachment suitable for the type of lens to be tested (FF/APSC) to the Lens Test
Projector (F).
Setting of Lens Test Projector (F)
Setting Procedure
1. Connect the camera and the Lens Test Projector (F) as shown in the figure below.
Note:
Configure the setting of a camera attached to the E-mount attachment as follows.
• Focus Mode: Manual Focus
• Shake Compensation: OFF
• Aperture: Open
2. Attach the lens to be tested to the Lens Test Projector (F), and set the equipment as shown in the figure below.
3. Set the zoom to the any position.
4. Turn ON the main switch of the Lens Test Projector (F).
5. Turn ON the lamp switch of the Lens Test Projector (F).
6. To set the lens surface and the screen in parallel, align the plane mirror with the center projected image on the screen and adjust the Lens Test
Projector (F) position so that the reflected light illuminates the lens to be tested.
7. Set the focus on the screen.
Note:
To finish the work, turn off the lamp switch of the Lens Test Projector (F), and after a few minutes confirm that the temperature of the Lens Test Projector
(F) has decreased, turn off the main switch.
Lens Test Projector (F)
Projection distance
Main switch
Lamp switch
E-mount APSC jig
E-mount attachment
Lens to be tested
Screen
Plane mirror
E-Mount Extension Jig
Camera
(General E-mount
interchangeable lens
digital camera)
