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4-5
SAL18552 (DT 3.5-5.6/18-55 SAM Ⅱ) (DT 18-55mm F3.5-5.6 SAM II)
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/mm
Center (y = 0)
Peripheral (y = 9)
Peripheral (y = 12)
S
M
S
M
18
1.20
100 lines or
greater
40 lines or
greater
32 lines or
greater
32 lines or
greater
25 lines or
greater
35
2.23
55
2.23
Table
4-3-1
5) Check the projective resolving power. If the projective resolving power does not meet the specification, perform 4-3-2. Projective
Resolving Power Adjustment .
4-3-2. Projective Resolving Power Adjustment
Check the projective resolving power. If the projective resolving power does not meet the specification, perform the projective resolving
power adjustment.
power adjustment.
Improve the projective resolving power in the following procedure.
1. Remove the front decoration plate, front ring and focus rubber ring.
2. Remove one screw fixing the 1st lens barrel block and adjust by rotating the 1st lens barrel block. (It can be rotated every 60 degrees.)
2. Remove one screw fixing the 1st lens barrel block and adjust by rotating the 1st lens barrel block. (It can be rotated every 60 degrees.)
Note:
Even if the 1st lens barrel block is adjusted by rotating, if the specification is not satisfied, replace the 2nd Lens barrel block.
If the specification is still not satisfied, replace the 1st Lens barrel block.
Focus Rubber Ring
Front Ring
Front Decoration Plate
1st Lens Barrel Block
Screw
Fig.
4-3-5
3. Perform the projective resolving power check again and confirm that the specification is satisfied.
4-1-2. Adjustment Flow Chart
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