The photograph is created by light forming an image, typically with the help of a lens. This image can be permanently saved through:
- Chemical means: This involves using film, liquid chemicals, and darkroom techniques.
- Digital media: This uses an electronic sensor, data storage, processing, and desktop printing.
Due to the accessibility, affordability, and environmental benefits of digital methods, photographers often combine both chemical and digital techniques for editing and printing. In modern photography, the convenience and speed of digital methods are commonly preferred.
Understanding chemistry or electronics isn’t necessary for taking good photos, but having practical skills to control the results is crucial for working confidently. Here’s an overview of the key technical steps in both chemical and digital photography:
The process of forming an optical image of your subject applies to both film and digital photography. Light from your subject passes through a glass lens, which focuses it into a concentrated image. This lens is on the front of a light-proof box or camera, with a light-sensitive surface, such as film, at the back. Light is blocked from reaching the film by a shutter until the moment of exposure is chosen. The amount of light exposure is controlled by the combination of the shutter’s open time and the diameter of the light beam passing through the lens, adjusted by an aperture similar to the iris of an eye. These two controls greatly affect visual outcomes: shutter speed influences how motion is recorded (blurred or frozen), while the aperture affects the depth of field.
To compose and aim the camera, you need a viewfinder, focus screen, or electronic display. A built-in light meter measures the brightness of the subject, considering the light sensitivity of the material you’re using to save the image. The meter determines an appropriate combination of lens aperture and shutter speed. With knowledge and skill, you can adjust these settings to achieve specific effects or compensate for conditions that might mislead the meter.
