Tilt-shift photography involves using special lenses that allow the photographer to tilt and shift the lens relative to the image sensor. Tilting changes the plane of focus, enabling selective focus and miniature effects, while shifting corrects perspective distortion, making it useful in architectural photography. Tilt-shift lenses give photographers creative control over focus and perspective, allowing for unique and artistic compositions that are difficult to achieve with standard lenses. This technique can create a surreal, toy-like appearance in images or ensure straight lines remain straight when photographing buildings.