APERTURE / IRIS
Amount of light reaching the sensor / controlled by the diameter of the opening.
Lens is calibrated in F-STOPS, the smallest numbers let in the greatest amount of light.
0.7, 1.0, 1.4, 2.0, …..
each stop halves or doubles the amount of light of the stop that came before.
F-stops adjusted to light absorption by the lenses. This is a more accurate
representation of real-world applications.
The widest value a lens can open. Divide the length of the lens by its maximum
DEPTH OF FIELD
The zone in which the image appears acceptably sharp.
Measured in terms of near distance and far distance from the camera.
Can be determined by looking up depth of field tables of using a depth of flied
Two main determinants of Depth of Field are the aperture of the lens and its focal
A shorter lens (wide angle) has a larger DoF than a longer (telephoto) lens.
DoF decreases as the lens opens up.
If there's too much light for proper exposure, you can use a neutral density (ND) filter to
ND3 reduces light by 1 stop, ND6 by 2 stops, ND9 and ND12 accordingly.
They also come in graduated versions in which only a part of it is darkened. You can
use it for bright skies.
Closest focus setting where the far limit of the depth of field extends to infinity.
INVERSE SQUARE LAW
Moving an object twice as far from lamp results in it being lit by 1/4 the amount of light.
Series of still photos in sequence on celluloid film coated with a light sensitive emulsion.
Standardized by Thomas Edison as 35mm wide and 4 perforations high.
Current formats also include 70mm, imax, etc.
24fps is the standard speed for theatrical release.
DIGITAL CINEMATOGRAPHY Digital image is captured on a sensor - CMOS or CCD.
Chip surface is a grid with pixels. Electrical charge builds up as light hits it.
Raw stock balance is for daylight (5600K) or tungsten (3200K).
You can correct mismatches by using gels, CTO or CTB.