Sigma Lens hood LH878-05

Sigma Lens hood LH878-05 for 24-70mm F2.8 DG DN II Art

A lens hood reduces stray light and lens flare (lens reflections). This can significantly improve the image quality of photos in certain lighting situations.

Lens flare can occur when one or more strong light sources shine directly onto the front element of the lens, usually direct sunlight.
Depending on the design and coating of the lens and the filters used, flare or a reduction in contrast due to stray light can vary in intensity. The shape of the lens reflections depends on the shape of the aperture. In contrast to stray light, lens flare does not always have a disturbing effect; it can also be used deliberately as a stylistic device for image composition.

A lens hood not only reduces the aforementioned phenomena but also provides additional protection for the front lens or the screwed-in filter against damage.