Source: wikibot/gray-card
= Gray card
{wiki=Gray_card}
A gray card is a tool used in photography and imaging to provide a neutral reference point for exposure and color balance. It typically comes in a neutral gray color, usually 18% gray, which is close to the average reflectance of a scene. Here's how it is generally used: 1. **Exposure Reference**: Photographers can use the gray card to set correct exposure.