Descripción
F1.8 Constant-Aperture Zoom for Fujifilm X APS-C
Overview
The Sigma 17-40mm F1.8 DC Art does something almost no zoom does: it holds F1.8 across its whole range. On APS-C that is a full stop and a half brighter than an F2.8 zoom, which means one lens can replace a bag of fast primes. This is the Fujifilm X mount version.
Key features
F1.8 all the way
- Constant F1.8 from 17 to 40mm: the aperture does not close down as you zoom, so exposure and background separation stay where you put them.
- A stop and a half over an F2.8 zoom: the difference between ISO 1600 and ISO 6400 indoors.
- 17-40mm on APS-C covers the wide-to-short-portrait range.
Art series optics
- 17 elements in 11 groups, with 4 SLD glass and 4 aspherical elements.
- 11 rounded diaphragm blades: an unusually high count, which keeps out-of-focus highlights round well into the stopped-down range.
- 28 cm minimum focusing distance and a 1:4.8 maximum magnification at 40mm.
Handling
- HLA (High-response Linear Actuator) autofocus: fast, quiet and precise.
- Aperture ring with a de-click switch: clicks for stills, silent for video.
- Dust and splash resistant, with a water and oil repellent coating on the front element.
- 530 g and a 67 mm filter thread in the X-mount version.
Specifications
- Mount: FUJIFILM X
- Format: APS-C (DC)
- Focal length: 17-40mm
- Maximum aperture: F1.8, constant
- Minimum aperture: F16
- Optical construction: 17 elements in 11 groups (4 SLD, 4 aspherical)
- Angle of view: 79.7° - 39.1°
- Diaphragm blades: 11, rounded
- Minimum focusing distance: 28 cm
- Maximum magnification: 1:4.8 at 40mm
- Filter size: 67 mm
- Dimensions (diameter x length): 72.9 x 118.2 mm
- Weight: 530 g
- Supplied: LH728-02 hood, LCF-67 IV front cap, LCR III rear cap, pouch
What it is good for
- Indoor events and weddings: F1.8 across the range, without changing lenses.
- Portraits on APS-C: 40mm at F1.8 gives real background separation.
- Low light and available light: it replaces a set of fast primes.
- Video: de-clickable aperture ring and quiet HLA autofocus.

