change of focal length

[Olivier Martinez]

Hi all,

how does the focal length change when shooting 1080 in comparison to 5k, by taking a 25mm for example? thank you!!

[Brian Drysdale]

The focal never changes. The field of view will change as the size of the sensor or film format changes. You can have 1080p or 5k with the same sized sensor (or even the same sensor), that will depend on how the photo sites are being read and then recorded eg ProRes or RAW,

 

Some cameras use windows, which may be what you're referring to, but the focal length stays the same.

 

This may help you.

 

http://www.abelcine.com/fov/

[Olivier Martinez]

Thank you, Brian!