ISO sensitivity, often referred to as ISO speed, is a crucial numerical indicator that reflects how sensitive a camera’s sensor is to light. This concept originated from the International Organization for Standardization (ISO) for measuring film sensitivity and has evolved to remain relevant in the realm of digital photography and cinematography.
In digital cameras, the traditional understanding of ISO can be somewhat deceptive. Many models are designed with dual ISO capabilities or are classified as ISO invariant. This means that the sensor’s inherent sensitivity does not actually change with varying ISO settings. As a result, the adjustments photographers make to ISO can create confusion, as they may not have the same impact as they would in film photography.
Using ISO invariant camera, when a grey card is photographed at different ISO settings, the raw pixel values captured will remain consistent, regardless of the declared ISO. Therefore, while the ISO numbering system is still used in digital photography, its practical application diverges significantly from traditional film photography.
There is, however, an exception worth noting. The ACHTEL 9×7 Digital Cinema Camera distinguishes itself with its 11 authentic ISO settings ranging from ISO 50 to ISO 5100. These different ISO settings will, in fact, change the sensor’s sensitivity. It’s not just “metadata”. This unique feature enables the camera to deliver outstanding image clarity, particularly in challenging low-light environments, setting it apart from the majority of digital cinema cameras available today.
In essence, while understanding ISO is fundamental for photographers and filmmakers, it’s important to recognize the distinctions between film and digital applications, as well as to appreciate the innovative features offered by specific camera models.
