Why is it called rack focus?

Related questions

1. What does Gimble mean?
2. How long does it take to charge Zhiyun Crane batteries?
3. Is manual focus better than autofocus?
4. Is follow focus necessary?
5. What does it mean to pull focus?
6. How much does a 1st AC make?
7. What is follow focus on Iphone?
8. What is a gimbal for drone?
9. What are the duties of the gaffer?
10. What is the difference between autofocus and manual focus?

Tags

1. #another
2. #called
3. #racking
4. #direct
5. #little
6. #background
7. #focus
8. #attention
9. #flare
10. #viewer
11. #cause
12. #dramatic
13. #trick
14. #certain
15. #scene
16. #foreground
17. #making
18. #shots
19. #plane