Remove 2 guide screws (12), circle clip (13), and inner ring (16).

f. Disassembly of Diaphragm.

(1) Remove rear optical components from lens tube (17).

(2) Remove retaining ring holding front optical components with tool 42-672.01-3-1W1NY. and slide out front optical components.

(3) Remove diaphragm guide ring and lift ten diaphragm blades from lens tube (17).

g. Remove dowel screw (18) and unscrew retaining ring (19), lift off focusing ring (20) with pressure spring (21) and sliding bar (22).

h. Remove 3 screws (23) and lift off depth-of-field ring (24). 3-14. Disassembly of 50mm Lens Head and Focusing Scale Assembly

(Fig. 43)

a. Unscrew lens mount (3) with index ring (5).

b. Remove set screw (4) and index ring (5) from lens mount (3).

c. Remove 2 set screws (6) and 1 dowel screw from diaphragm adjusting ring (7) and remove adjusting ring from lens tube (14).

NOTE: Do not lose flat spring (8) and ball (9) when sliding off adjusting ring.

d. Remove 2 guide screws (10) and lift off inner ring (13).

e. Removal of Diaphragm Blades.

(1) Lift diaphragm guide ring (11) from lens tube (14).

(2) Remove 10 diaphragm blades (12).

f. Lift out cover ring (15) and remove retaining ring (16).

g. Lift off focusing ring (19) with components.

h. Unscrew sleeve (17) and remove spring ring (18) and stop ring (25) with segment (23).

i. Remove 3 screws (22) and segment (23). j. Remove screw (20) and stop (21).

3-15. Partial Disassembly of 50mm Helical Focusing Assembly

(Fig. 44)

Remove 2 screws (3), segment (4). stop spring (5) and nipple (2).

3-16. Partial Disassembly of 50mm Viewing Unit

(Fig. 45)

Optical components and their mounts are permanently bonded. Disassembly is limited to that required for repair of replaceable parts.

a. Remove 2 screws (12) and finger grip (13).

b. Remove screw (15) and stop (16). 3-17. Disassembly of 135mm Lens Head

(Fig. 46)

a. Remove filter retaining ring (2).

b. Remove retaining ring (3), stop ring (4), inner lens hood tube (5), outer lens hood tube (7), and lens hood liners (6) and (8).

c. Remove stop ring (4) and separate lens hood tubes (5) and (7).

d. Remove 3 set screws (9) and slide off diaphragm adjusting ring (10). NOTE: Take care that flat spring (12) and ball (11) are not lost.

e. Remove set screw (13) and unscrew lens mount (14) from lens tube (21).

f. Remove circle clip (15) and inner ring (16).

g. Removal of Diaphragm Blades.

(1) Remove guide screw (17), circle clip (18) and lift out diaphragm guide ring (19).

(2) Remove 12 diaphragm blades (20). 3-18. Disassembly of 135mm Focusing Mount

(Fig. 47)

a. Remove 2 screws (4), tripod bushing plate (5), and screw (6).

b. Unscrew coupling ring (located between viewing unit assembly (7) and depth-of-field ring (13)) using tool C42-37.01-U60T6. Slide off helical focusing assembly (14).

c. Remove 6 screws (2) and bayonet ring (3) and lift differential cam assembly (8) from viewing unit (7).

d. Remove screw (9), nut (10), and stop (11).

c. Remove retaining ring (12) with tool 42-37.01-U60W3NY.

f. Remove depth-of-field ring (13) from helical focusing assembly (14).

3-19. Partial Disassembly of 135mm Viewing Unit

(Fig. 48)

Optical components and their mounts are permanently bonded, except element (15). Disassembly is limited to that required for repair of replaceable parts.

a. Remove 2 cover screws (1).

b. Remove 4 screws (2), 3 screws (3), and cover plate (4).

c. Remove 1 screw (6), retaining plate (7), and pressure spring (8).

d. Loosen 2 adjusting screws (13) and remove flat spring (14) and optical element (15).

a. Remove screw (3).

b. Remove ring nut (2) with tool 42-471-117W3NY.

c. Turn lower reflector segment (8) slightly, and slip the segment cleat out of the slot.

d. Remove the segment cleat from the reflector segment adjacent to segment (8).

e. Repeat the procedure in d above until segment cleats have been removed from all reflector segments.

3-21. Disassembly of Bayonet-Base Lamp Adapter

Section IV. FLASH UNIT

3-20. Disassembly of Reflector

(Fig. 49)

(Fig. 50)

Remove 3 screws (2) and slide bayonet socket shell (3) off intermediate sleeve (6).

Remove ejector button (4) and release spring (5).

Pull intermediate sleeve (6) off socket inner sleeve (9).

Remove screw (7) and contact pin (8).