Ver 1.1 2007.02

2. 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).

The number represents for lines per mm.

Saggital (S)

Meridional (M)

Fig.4-3-3

3)Turn the mount rotation ring of lens test projector until the projected image at a certain peripheral point (y’= 15) on the screen appears the most unsharp.

Read the number of the smallest pitched lines (both saggital and meridional: 3 lines) at the peripheral point.

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.

Do not confuse spurious resolution for the smallest pitched lines.

Correct resolution

Spurious resolution

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fig.4-3-4

4)Check that the all readings (y’= 0, saggital (S) and meridional (M) at y’= 15) is within the specification of the Table 4-3-2.

Specification

 

Number of the smallest pitched lines

 

 

 

 

Distance (m)

Center (y’= 0)

Peripheral (y’= 15)

 

(Lines per mm)

(Lines per mm)

 

 

 

 

 

 

S

M

 

 

 

 

1.4

125 or greater

50 or greater

40 or greater

 

 

 

 

Table 4-3-2

5)After the checking is completed, turn the lamp switch of the lens test projector to OFF and cool the inside of the lens test projector, then turn the fan switch to OFF.

SAL35F14G (1.4/35G) (35mm F1.4G)

4-20

Page 59
Image 59
Sony SAL35F14G service manual Number of the smallest pitched lines