Sigma 18-50mm f/2.8 DC DN C (Contemporary) Autofocus APS-C Lens for Fujifilm X-Mount, Black {55}

Model #390042

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Sigma 18-50mm f/2.8 DC DN: the compact constant-aperture zoom Fujifilm X shooters needed.

At 290 grams and 74.5mm long, this is one of the smallest constant f/2.8 standard zooms built for APS-C mirrorless. The 27-75mm full-frame equivalent range covers the most useful focal lengths in a single barrel, and the aperture never stops down as you zoom. That matters in low light and whenever subject separation is the point. Thirteen elements across 10 groups include three high-precision glass-molded aspherical elements and a special low dispersion element, a tight optical formula that keeps weight down without trading away correction.

The stepping motor AF runs fast and near-silent, which translates directly to usable performance during video recording and when tracking unpredictable subjects. Minimum focusing distance sits at just 12.1 cm with a 1:2.8 maximum magnification, so the lens pulls close-up duty without a dedicated macro. The 55mm filter thread is a reasonable size for this class, and the seven-blade rounded diaphragm produces smooth out-of-focus rendering at f/2.8. For Fujifilm X shooters who want one lens that earns daily carry, the optical output and physical footprint here are difficult to match at any price.

Who It's For

Street photographers working with smaller Fujifilm bodies will appreciate the 290g weight and 74.5mm length, the kit doesn't announce itself. Travel and documentary shooters get a 27-75mm equivalent range that handles wide environmental shots and tighter portraits without a bag change. Video producers and vloggers benefit from the near-silent stepping motor AF, which avoids audio contamination during recording. Photographers who regularly work close to subjects get genuine close-up capability from the 12.1 cm minimum focusing distance and 1:2.8 magnification, without carrying a second lens.

Key Features

  • Constant f/2.8 aperture across 18-50mm focal range
  • 27-75mm full-frame equivalent on APS-C
  • 13 elements in 10 groups with aspherical and low-dispersion elements
  • Stepping motor autofocus for fast, silent operation
  • 1:2.8 maximum magnification with 12.1cm minimum focus distance
  • 290-gram weight, 74.5mm length for daily-carry portability
  • 55mm filter thread, seven-blade rounded diaphragm

FAQ

What's the actual field of view on an X-T5 or X-H2S?
The 18-50mm gives you a 27-75mm equivalent range on APS-C, so you're looking at wide-to-short-telephoto coverage - wider than a standard 35mm lens at the short end, tighter than an 85mm at the long end.
Can you use this for close-up work without a macro lens?
Yes. The 1:2.8 maximum magnification and 12.1cm minimum focusing distance handle close-ups without needing dedicated macro glass, though it's not a true 1:1 macro lens.
How does autofocus perform during video?
The stepping motor AF is fast and near-silent - specifically designed for video work and unpredictable subjects like children or animals without hunting or noise.
What's the weight penalty for that constant f/2.8 aperture?
290 grams. It's one of the lightest constant-aperture f/2.8 standard zooms made for APS-C mirrorless, which matters if you're building a travel kit.
Does the aperture stay f/2.8 all the way through the zoom?
Completely. The aperture doesn't stop down as you zoom from 18mm to 50mm, which preserves subject separation and low-light capability across the entire range.
What glass correction is built in?
Three high-precision glass-molded aspherical elements plus a low dispersion element handle distortion, vignetting, and chromatic aberration - supported by in-camera correction on Fujifilm bodies.
Is the bokeh actually smooth at f/2.8?
The seven-blade rounded diaphragm produces clean out-of-focus rendering without the polygonal artifacts you get from cheaper aperture designs.
SpecificationValue
Focal Length18-50mm
Max Aperturef/2.8
Min Aperturef/22
MountFujifilm X
Filter Thread55mm
Lens Elements13
Lens Groups10
Angle Of View76.5° - 31.7°
Minimum Focusing Distance4.8" / 12.1 cm
Maximum Magnification1:2.8
Length2.9" / 74.5 mm
Maximum Diameter2.5" / 64.5 mm
Package Weight0.995 lb
Box Dimensions6.2 x 4.2 x 4.1"
Full Frame Equivalent Zoom27-75mm
Weight10.2 oz / 290 g

This description was generated using AI based on KEH's internal product standards, product expertise, and knowing what customers care about most. While we strive for accuracy, details may vary by individual item.

Brand Name Sigma
Filter Size 55mm
Focus Type Autofocus (lens motor)
Lens Mount Fuji XF Digital
Lens Type Standard / Normal
Max Focal Length 50mm
Min Focal Length 18mm