Real World Lenses - Todd Cherniawsky

Matching lens size to real world cameras is imperative when you are working with back- ground plates. The following tips and tables will help Imagineers greatly.

1. There are two tables, one for 16mm lenses and one for 35mm lenses. These tables include a pretty standard range of prime lenses, and the lens lengths are in millimeters (mm).
2. These values are for standard 1:1.33 (academy aperture) and full frame four perf 35mm motion picture film.
3. Still lenses are closer to VistaVision (list not included).
4. For the ACTION/STAGE EDITOR, the CAMERA SIZE values should be set to the following values:
   X = 320.0000
   Z = 240.0000
5. If using a letterboxed format such as 1:1.66, 1:1.75, 1:1.85, etc., adjust the Z axis according to the third table to see accurate CAMERA LINES in the STAGE EDITOR.
6. scale the camera up or down as necessary in order to see the CAMERA LINES or if you're doing DEPTH OF FIELD rendering. NOTE You MUST scale ALL AXIS together!
7. Bonus for DOS and AMIGA users. The Horizontal Field of View (in degrees) can be used in the DISPLAY/PERSPECTIVE/FOV ANGLE requestor for Imagine for DOS and AMIGA (there is no FOV ANGLE requestor in IFW).

	16mm LENSES 16 = 16mm lens equivalent (mm) H = Horizontal Field of View (degrees) Y = Imagine Camera Size : Y value (Imagine Units) NOTE To convert any 16mm lens to Imagine Y Units, multiply the lens focal length by 33.3333.
	35mm LENSES 35 = 35mm lens equivalent (mm) H = Horizontal Field of View (deg) Y = Imagine Camera Size : Y value (IMU) NOTE To convert any 35mm lens to Imagine Y Units, multiply the lens focal length by 15.2381.
	LETTERBOXED Z VALUES LAR = Letterboxed Aspect Ratio Z = Imagine Camera Size : Z value (IMU)

Here is a short table of aspect ratios and their closest pixel count equivalents: