ASA and ISO Settings

The American Standards Association (ASA) provides a specification, which determines how sensitive the film is to light. A higher ASA number represents a higher sensitivity to light. Usually digital cameras use the International Standards Organisation (ISO) specification, which refers to the sensitivity of the CCD imaging system. However, many film manufacturers provide both numbers as they mean the same thing. The ASA number, usually found on the box, is also on the metal container, and usually cameras have a little window on the film compartment lid, which displays the markings on the roll of film.

Olympus Trip 35 ASA Settings

The Olympus Trip 35 has the following ASA setting options, 25, 40, 50, 64, 80, 100, 125, 160, 200, 250, 320, and 400. Simply look on the film cartridge for the ASA type and set it on the camera. The camera then makes the necessary adjustments for the shutter speed.

The Dot

On the ASA ring, there is a dot between two settings. This is for film speeds with a value between those two numbers. If you had a film with speed 66, then you would set the ring to "64 dot".

The camera programming relies on the user setting the correct value, as all the other decisions such as aperture and shutter speed depend upon it.

Manual Control

If you are using the camera in manual mode, it is important to remember some basic principles of exposure, as the aperture, and the shutter speed, controls the amount of light entering into the camera. A fast shutter speed lets less light enter the camera, and the images are therefore coarser grain, hence a higher ASA number film is used. A slow shutter speed lets more light enter the camera, and the images are therefore finer grain, hence a lower ASA number film is used. A good photographer usually knows how to balance these parameters to get the best exposure for every condition. Alternatively, if the thinking is too difficult, then one may also set the camera to "Auto", and adopt the "point and shoot" style.

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