Film and Lens Lecture

Southern Methodist University – Spring Term 2007
117 Umphrey Lee, Mondays 9:00-11:50am
Robert Flowers, Instructor

Film Black and White Reversal

Film Layers:

  • Supercoat
  • Emulsion
  • Subbing Layer (Adhesive)
  • Base
  • Subbing Layer (Adhesive)
  • Anti-Halation Layer

Silver Halides Crystals: Light sensitive particulars
Sensitometry: Emulsion sensitivity to light
Latent Image: Exposed non-developed image

Black & White Reversal Film Development:

  • Developer
  • Bleach
  • Exposure
  • Developer
  • Bleach
  • Fixer

Kodak Film Types

Kodak Film Tools

The Characteristic Curve

Film Speed & ASA:

  • Speed equals sensitivity to light
  • EI=exposure index (gives “speed” a number)
  • EI=ASA=DIN (Metric)
  • Example: Tungsten EI160/23 Daylight EI200/24
  • 200 ASA medium/slow
  • ASA 200=twice sensitivity as ASA 100

Single Perforation (standard 16, super 16 only)

Double Perforation (standard 16, high speed)

Camera Stocks = Winding B

40 Frames = 1 foot

Film pitch

Film sizes

70mm release stock only

65mm, 35mm, 16mm, Super 8mm, 8mm

Light Meter

  • Incident light = light falling on subject (dome = human face)
  • Reflective light = light bouncing off subject
  • Spot meter reads reflective light very narrow angle

Backlight compensation

Tonal range

Lenses = several elements contained within circular barrel

In 16mm film the 25mm lens = “normal” field of human vision

Prime lenses = fixed focal length = fast lens
10 mm to 100 mm

Zoom lenses = adjustable focal length = slow lens
10 mm to 120 mm

Telephoto lens = fixed long focal length = slow lens
100 mm +

Lens focus = light aimed precisely at film plane

Lens focal length = distance from optical center of lens to focal plane/film plane e.g. 25mm, 50 mm, 75mm, etc.

F-Stop = amount of light allowed by lens diameter, focal length and lens aperture (iris opening) e.g. f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, etc.

Depth of field = range in which objects will appear sharp. Also considered the area of focus starting at 1/3 distance in front of point of focus to 2/3 after point of focus (1/3 Rule).

Greater Depth of Field

Wide angle lenses

High F stop (small aperture)

Subject far away from camera

Smaller format (such as 8mm film)

Less Depth of Field

Telephoto lenses

Low F stop (wide aperture)

Subject close to camera

Larger format (such as 35mm film)

Hyper focal distance = point of greatest depth of field. It is pre-calculated figure indicating that if the given lens at the given F stop is focused at this hyper focal distance, everything from half this distance to infinity will be in an acceptable focus. For example, if for a given lens and f-stop the hyper focal distance is 20 feet, by focusing at 20 feet we would obtain everything in focus from 10 feet to infinity.

Depth of Focus

Refers to the very small distance on either side of the focal plane where the film can be situated and still record an acceptably sharp image.

To get a correct exposure

Set film ASA > set shutter speed on light meter = F stop

Add filter compensation and/or shutter adjustment = adjusted F stop


Film speed = e.g. Tri-X Reversal EI 160T, EI 200D, Plus-X Reversal EI 80T, EI 100D

Set Shutter Speed

1/80th at 24 fps (Bolex)

If Necessary

Make F stop adjustments for:
Adjustable shutter
Filter compensation

Set F Stop on Lens