Film Speed - SimCam - Film and Digital Camera Simulator

Film Speed Simulation

All film has a speed rating - even digital cameras use the common ASA speed index. Slower films produce sharper images but require large amounts of light. Fast films can be used in low light situations in exchange for an increase in contrast and noise/grain.

speed rating	sensitivity	contrast	grain
50 ASA	low	low	low
100 ASA	medium	medium	medium
200 ASA	medium	medium	medium
400 ASA	high	high	high
800+ ASA	very high	very high	very high

50ASA is slower than 100ASA, and requires 1 stop more light
400ASA is faster than 100ASA, and requires 2 stops less light

Sometimes using a faster film speed is the only way to get a sharp image. Try the following example to learn how shutter speed, aperture, AND film speed all use the interchangable photographic "stop".

SimCam Film Speed Example:

First set both SimCams to 1/60 f4 and shoot a picture. The 400 ASA film is overexposed, so you need to compensate by reducing light - move the shutter or aperture 2 stops higher to balance the exposure. (For example move the shutter to 1/250, or the aperture to f8)

All stops are interchangable. By going from 100ASA to 400ASA, you have two stops more light. You can "spend" those stops on aperture or shutter speed.

Notice the increased grain and contrast of the 400ASA example. Remember, if you need more light than, you can increase the film speed.

100ASA Film

400ASA Film

Shutter:

Aperture:

Shutter:

Aperture:

final exposure: