Sigma 15mm F1.4 DG DN Diagonal Fisheye Art

The Sigma 15mm F1.4 DG DN Diagonal Fisheye Art is a full-frame prime made for Sony E and Leica L mirrorless cameras. The two mount versions are separate lenses, so pick the one that matches your camera. Sigma launched it in 2024, and it remains in production. As a diagonal fisheye, its 15mm design strongly curves the frame instead of keeping straight lines.

The bright F1.4 aperture and 15mm focal length make it a natural fit for night-sky photography, from Milky Way fields to aurora. It also suits tight interiors and bold environmental portraits that embrace the curvature. The trade-off is that any scene needing straight lines, such as architecture, will need a different lens or later correction.

It weighs 3 lb 0 oz (1360 g) and measures 4.09 in (104 mm) across and 6.22 in (157.9 mm) long. That is heavy for a wide prime. The front accepts no screw-in filters, so you cannot fit a standard threaded ND or polariser directly.

The 15mm focal length is extremely wide. Because this is a diagonal fisheye, straight lines bow away from the centre, and shapes stretch near the frame edges. Placing key subjects near the middle keeps them looking more natural.

F1.4 is very bright for a lens this wide. The extra light helps night-sky work, where you can use shorter shutter times to keep stars as points while still recording faint detail. The same brightness helps in dim interiors, letting you avoid very high ISO settings.

Closest focus is 1.3 ft (38.5 cm), so you can work very near a foreground subject. A rock or doorway close to the camera looms large while the wide frame keeps the surrounding scene. That exaggerated near-far perspective is a core part of fisheye photography.

Eleven aperture blades help the opening stay round when stopped down. Small out-of-focus highlights, such as lamps in an evening interior, then render as smooth round shapes rather than hard-edged polygons. This specification set scores 87 out of 100 in our optics assessment.

Weather sealing helps keep dust and moisture out of the lens. That matters for night shoots in cold, damp air and for landscape work in changing weather. A fluorine coating helps water and dirt slide off the glass, so it cleans up quickly after a dewy night.

There is no image stabilization. At 15mm, hand-held shutter times can be fairly long before shake shows, but night-sky work happens in near darkness. Plan on a tripod for the darkest scenes. Our features score for this lens is 52 out of 100.

The optical path uses 21 elements in 15 groups. Two aspherical elements help correct distortion and spherical aberration, useful in such an extreme wide design.

Seven low-dispersion elements help reduce chromatic aberration, the coloured fringing that can appear along high-contrast edges such as bright stars against dark sky. Internal focusing keeps the focusing movement inside the barrel rather than extending the front.