A negative is a film image with inverted tones. The darkest parts of the scene appear lightest on the film, and the lightest parts appear darkest. This inversion happens because the film is coated with silver halides that darken when exposed to light. The negative is the intermediate step between the scene and the print. It is developed, fixed, and washed, then used to make positive prints through an enlarger or a contact printer.

Negatives come in different formats. 35mm is the most common, with a frame size of 24mm by 36mm. Medium format is larger, usually 6cm by 6cm or 6cm by 4.5cm. Large format is larger still, often 4x5 inches or 8x10 inches. Larger negatives hold more detail and can produce larger prints with less grain. Negatives are fragile. They scratch, collect dust, and degrade over time. Proper storage, in archival sleeves and cool, dry conditions, extends their life. Many photographers still shoot film, and many more have boxes of negatives in closets and attics. Digitizing them preserves the images for future generations.

Negative formats

• 35mm. 24mm by 36mm, most common.
• Medium format. 6cm by 6cm, 6cm by 4.5cm, 6cm by 7cm.
• Large format. 4x5 inches, 8x10 inches.
• Sheet film. Individual sheets, used in large format cameras.

A negative is not a photograph. It is the raw material for a photograph. The print is the final image, but the negative is the source.