FOV

[David Calson]

I'm lens illiterate, spoiled by zooms, so I'm trying to get better suited with primes. What's got me caught up is field of view. For example, I know 35mm is wider than 75mm, but I don't know how much of the scene that lens actually captures.

 

I'm afraid of putting a lens on only to find I'm right on the actresses nose or that my wide lens is too wide. How do you the lens you put on covers exactly the amount you want to see?

 

Thank you.

[Mike Lary]

It shouldn't take you long to get a sense of what each lens covers once you start working with them more, but in the meantime you can look at field of view charts to determine exactly what your frame will look like. You can look up your field of view for each shot, then jot focal length and camera distance on your shot list so you don't end up walking the camera back and forth on set and swapping out lenses. The ASC manual has charts and you could also use PCAM if you have a Palm Pilot of PalmOS emulator on your computer.

[Michael Nash]

There's a straightforward geometric relationship between focal length and field of view. A focal length that's twice as long sees exactly half as wide.

 

Start simple with three focal lengths; a focal length that's "normal" for the format, one that's half that length, and one that's double that length. In the 35mm format these would 25mm, 50mm, and 100mm. Consider these three equal steps as your standard of reference for "wide," "medium," and "tight." Of course these definitions are arbitrary, but it's a useful start. Then, add two more intermediate focal lengths, "medium wide" (35mm) and "medium tight" (85mm). You'll find that the three "medium" lenses will become your workhorse focal lengths for story telling, and the wide and tight lenses will be reserved for wide masters and tight inserts. Anything beyond your wide and tight focal lengths you can consider "very wide" or "very tight," again remembering that the field of view is mathematically derived from the focal length.

 

Use this as a starting point. After a while you'll develop your own style and uses of focal lengths.

Edited April 19, 2008 by Michael Nash

[David Calson]

There's a straightforward geometric relationship between focal length and field of view. A focal length that's twice as long sees exactly half as wide.

 

Start simple with three focal lengths; a focal length that's "normal" for the format, one that's half that length, and one that's double that length. In the 35mm format these would 25mm, 50mm, and 100mm. Consider these three equal steps as your standard of reference for "wide," "medium," and "tight." Of course these definitions are arbitrary, but it's a useful start. Then, add two more intermediate focal lengths, "medium wide" (35mm) and "medium tight." You'll find that the three "medium" lenses will become your workhorse focal lengths for story telling, and the wide and tight lenses will be reserved for wide masters and tight inserts. Anything beyond your wide and tight focal lengths you can consider "very wide" or "very tight," again remembering that the field of view is mathematically derived from the focal length.

 

Use this as a starting point. After a while you'll develop your own style and uses of focal lengths.

 

 

Very enlightening sir, and you spared me the complicated math, thanks!