Exposure of negatives

Exposure in photography is the amount of light that reaches the photographic film or detector. It is the direct result of the light intensity, shutter speed and aperture size of the lens. Exposure is one of the most important aspects of taking photographs, and it impacts the overall look and feel of an image.

Exposure is determined by the amount of light hitting the subject and being recorded by the camera’s sensor. The amount of light determines how bright or dark an image will appear. If an image is too dark, it is said to be underexposed, and if it is too bright, it is said to be overexposed.

When photographing on film, photographers have to consider the type of film being used in the camera. Different types of films react differently to light, and the correct exposure is determined by the type of film and the light intensity. For example, black and white film is sensitive to light, so it requires a shorter exposure time than color film.

The correct exposure is determined by the three main variables of shutter speed, aperture, and ISO. ISO (International Organization for Standardization) is a measure of sensitivity to light for photographic film, and it is typically set at 100 for daylight conditions. Shutter speed determines how long the camera’s shutter stays open, and aperture is the size of the opening in the lens, which impacts the amount of light that enters the camera.

When selecting the correct exposure settings, it is important to take into consideration the type of subject being photographed. For example, if the subject is a fast-moving object, it would require a faster shutter speed to freeze the motion, and a wider aperture to allow more light in. On the other hand, if the subject is slow-moving or stationary, a longer shutter speed and a smaller aperture would be used to create a longer exposure time.

It is also important to consider the environment when photographs are taken. For example, night photography requires longer exposures than day photography, and the light intensity of the environment will affect the correct exposure. Photographers must also consider the correct exposure settings when photographing in a low light environment.

In conclusion, exposure is one of the most important aspects of taking photographs. It determines the overall look and feel of an image, and it is directly related to the three main variables of shutter speed, aperture, and ISO. It is important to consider the subject being photographed and the environment when selecting the correct exposure settings to ensure that the best-looking photograph is achieved.

底片曝光（Film Exposure）

Film exposure is the process of making a film sensitive to light. It can be used to produce pictures in traditional photography, and also forms part of the processes of filmmaking and photojournalism.

To prepare a film for exposure, it is placed in a light-proof container and loaded into a camera. An aperture then opens, allowing light to pass into the camera and onto the film. This is known as an “exposure”.

The amount of exposure is determined by the camera settings, specifically how much light is allowed to enter. For example, the wider the aperture, the more light will enter and the faster the film will be exposed. Additionally, the amount of time during which the aperture is open will also be taken into consideration.

If the film is not exposed for a long enough period of time, the image may not be adequately developed and the picture will be dark and unclear. On the other hand, too long of an exposure will cause the image to be too light and washed out.

Once exposure has taken place, the film must be developed. This is done by placing the film into a chemicals bath which will cause the light-sensitive silver crystals on the film to create a visible image.

The process of film exposure is the same throughout photography and video production. The only difference is that in film, the shot must be taken multiple times and then manually cut together to form the final product.

Overall, exposure is how light is captured and transformed into a visible image. It is an important step in the processes of photography, filmmaking and photojournalism. When done correctly, exposure can result in stunning pictures and works of art.