The ASA/ISO setting on a film camera affects the camera’s sensitivity to light. Changing the ASA/ISO value will have an impact on the film’s exposure, as well as on the final image’s graininess. Higher ASA/ISO values will make the film more sensitive to light, which can result in a brighter image, but may also result in more grain or noise.
When shooting with film, the ASA/ISO value is determined by the film you are using. Each type of film has a specific ASA/ISO rating, which can range from as low as 25 to as high as 6400. Changing the ASA/ISO value on the camera will not change the film’s actual sensitivity to light, but it will affect the camera’s metering system, which determines the correct exposure settings for a given scene.
If you set the camera’s ASA/ISO value to a higher number than the film’s rating, you will essentially be overexposing the film, which can result in brighter images with more detail in the shadows. However, this will also result in more noticeable grain in the final image. Conversely, if you set the camera’s ASA/ISO value to a lower number than the film’s rating, you will be underexposing the film, which can result in darker images with less shadow detail but also results in finer grain in the final image.
It is important to note that changing the ASA/ISO setting on a film camera is not the same as changing the ISO setting on a digital camera. With a digital camera, changing the ISO setting affects the camera’s amplification of the signal from the sensor, which can result in increased noise in the final image. With film, the ASA/ISO rating is determined by the film’s physical properties, so changing the camera’s ASA/ISO setting does not affect the film’s actual sensitivity to light.
In conclusion, changing the ASA/ISO setting on a film camera will affect the camera’s metering system and can result in brighter or darker images with more or less grain in the final image. However, it is important to note that this does not change the film’s actual sensitivity to light. As with all technical aspects of photography, it is important to consider the specific characteristics of the film being used and the desired outcome before making any adjustments to the camera’s settings.
