The Sigma 17-40mm f/1.8 DC Art is a premium constant-aperture zoom lens engineered for APS-C mirrorless shooters who demand professional-grade optical performance in a portable package. With its exceptional f/1.8 aperture throughout the entire 17-40mm range, this lens combines the versatility of a zoom with the light-gathering power and image quality traditionally reserved for prime lenses. Its advanced optical design features 17 elements in 11 groups, including SLD and aspherical elements for outstanding clarity and minimal aberrations. Whether you're capturing cinematic video, low-light photography, or travel imagery, the internal zoom mechanism and minimal focus breathing deliver smooth, stable results on gimbals or handheld rigs. At over 30% lighter than its legendary predecessor and featuring a compact 67mm filter diameter, this Art lens is built for mobility without compromise.