Maintain required focus and camera operation throughout shoots

Business Sectors (Suites): Camera
Developed by: ScreenSkills
Approved on: 29 Mar 2020


​This standard is about focusing lenses and maintaining and adjusting focus to meet requirements and monitoring camera operation whilst shooting.  This can apply to digital or film cameras.  This could apply to any type of production including feature films, TV dramas, commercials, documentaries, sports coverage, outside broadcast and live or stage events. 

This includes assessing requirements, making calculations, maintaining focus, making focus changes, monitoring camera operation and resolving problems.

This standard is relevant to those working as 1st Assistants, Focus pullers or lone Camera operators.

Performance criteria

You must be able to:

  1. ​assess focus required to meet production requirements
  2. calculate focus splits, depth of field and hyperfocal distances required for shots
  3. discuss and agree splits or changes of focus with relevant people
  4. make any required focus marks in liaison with relevant people to meet production requirements
  5. make sure you have sufficient time for any required rehearsal or preview of shots
  6.  inform appropriate people when camera is ready for shooting
  7. maintain focus throughout shots in line with production requirements
  8. time focus changes to meet production requirements
  9. report any suspicion of soft focus to relevant people without delay
  10. monitor operation of cameras throughout shoots
  11. take appropriate action to resolve any problems with cameras with minimal disruption to productions
  12. handle cameras in ways that do not cause damage
  13. make sure that cameras remain safe and secure when left unattended
  14. work in line with health and safety requirements at all times

Knowledge and Understanding

You need to know and understand:

  1. ​key characteristics of current cameras, lenses and attachments and major obsolescent models
  2. relevant manufacturers' instructions for the equipment in use
  3. the limitations of chosen equipment when production requirements change
  4. software for framerate and the impact of framerate on camera memory
  5. camera handling techniques and the implications of damage to cameras
  6. how to interpret primary subject movement, camera movement, aesthetic judgment and other production requirements
  7. how to make focus marks and when they are required including measuring points, marking up lens focus scales and marking sets
  8. how to make required calculations including those for focus splits, depth of field and required rehearsal and shot preview time
  9. charts and tables available to assist with calculations and how to use them
  10. how depth of focus and hyperfocal distance affect depth of field calculations
  11. how to maintain focus without continuous reference to calibration or disturbing cameras
  12. the role of others involved and when to liaise with them including directors of photography, camera operators, directors and 2nd camera assistants
  13. how to identify problems with camera operation including warning signals and noise
  14. the requirements of relevant health and safety legislation and procedures
  15. any special requirements to ensure the safety and security of equipment when left unattended


Scope Performance

Scope Knowledge





Links To Other NOS

External Links

Version Number


Indicative Review Date

30 Mar 2024





Originating Organisation


Original URN


Relevant Occupations

Arts, Media and Publishing, Media and Communication, Media Associate Professionals

SOC Code



camera; lens; lens parameters; camera operations; camera models; equipment and accessories; focus;