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

Model #389146
  • $511.00

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Our Grading System
New in box complete with manufacturer's USA warranty. Not previously owned or used.
Essentially new with no signs of use. “Open box.” In manufacturer's packaging with original accessories and instructions. 180-day warranty.
Barely used with virtually no traces of wear. Only the closest inspections will reveal slight use. Lens glass could contain light dust or debris. Excellent picture quality. Accessories usually not included, unless noted in listing. 180-day warranty.
Lightly used with limited signs of wear. Exceptionally nice but may have slight wear on finish visible. Lens glass could contain light dust or debris. Excellent picture quality. Accessories usually not included, unless noted in listing. 180-day warranty.
Noticeably used with average signs of wear. Shows moderate wear for the age of the item, with the possibility of blemishes and/or minimal dings. Lens glass may have average dust and zoom/focus ring tension may have slight looseness or tightness overall, but will not affect picture quality. Accessories usually not included, unless noted in listing. 180-day warranty.
Frequently used with above-average wear. May have dents, dings, or finish loss. Lens glass may have small scratches, dust, and blemishes, and zoom/focus ring tension may have moderate looseness or tightness overall, but should not affect picture quality. Accessories usually not included, unless noted in listing. 180-day warranty.
Heavily used with extensive visible wear. Equipment is rough, with multiple impressions in the finish, excessive finish loss and brassing. Glass will have marks, fungus and/or heavy/cloudy haze which could affect picture quality. Accessories usually not included, unless noted in listing. Not covered under KEH warranty.
Non-functional or damaged. Equipment will not work. Usable for parts. Not covered under KEH warranty and non-returnable.
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Sigma's 290g constant-f/2.8 zoom built for APS-C mirrorless.

A constant f/2.8 aperture across a 18-50mm range in a body weighing 290g and measuring just 74.5mm long, that combination is genuinely rare. Sigma achieved it by pairing three glass-molded aspherical elements with a special low dispersion element in a 13-element, 10-group formula, keeping optical corrections tight without stacking glass unnecessarily. The 27-75mm full-frame equivalent range covers wide-angle to short telephoto, which handles most what most shooters reach for day to day.

The stepping motor AF is fast and near-silent, which matters in two specific situations: video, where a buzzing focus drive ruins audio, and shooting subjects that move without warning. A minimum focusing distance of 4.8 inches gives you a 1:2.8 maximum magnification, so product details and close environmental shots are within reach without a dedicated macro lens. The 55mm filter thread keeps polarizer and ND costs reasonable.

For Leica L mount shooters, this is the kind of lens that earns permanent bag space. It covers the focal lengths where most images actually get made, opens wide enough to work in mixed or low light, and doesn't punish you on weight when you're also carrying a body, batteries, and cards all day.

Who It's For

Travel photographers moving fast through changing environments benefit from the 27-75mm equivalent range and 290g weight, wide enough for architecture and tight enough for candid portraits without swapping glass. Videographers and content creators working handheld or on a gimbal get near-silent stepping motor AF and a constant f/2.8 that holds exposure through the full zoom. Event shooters working in low or mixed light can lean on the f/2.8 aperture without going to a heavier f/2.8 full-frame zoom. Street photographers who want close-focus capability alongside a general-purpose range get the 4.8-inch minimum focus distance as a genuine bonus.

Key Features

  • 18-50mm f/2.8 constant aperture throughout entire zoom range
  • APS-C mirrorless format with 27-75mm full-frame equivalent
  • 10-group, 13-element design with three glass-molded aspherical elements
  • Stepping motor autofocus, fast and near-silent for video
  • 4.8 inch minimum focusing distance with 1:2.8 magnification
  • 290g weight, 74.5mm length for portable daily use
  • 55mm filter thread

FAQ

What's the full-frame equivalent focal length for this lens on APS-C?
27-75mm, which covers wide-angle to short telephoto on full-frame terms. That's the range where most shooters actually make images.
Is autofocus quiet enough for video?
Yes. The stepping motor is near-silent, which matters because a buzzing AF motor ruins audio on recording.
Can you shoot close-ups without a macro lens?
The 4.8" minimum focusing distance and 1:2.8 maximum magnification handle product details and environmental close-ups without dedicated macro glass.
How much does this lens weigh?
290g (10.2 oz), light enough that it doesn't punish you over a full day of shooting with body, batteries, and cards.
What filter size does it use?
55mm, which keeps polarizer and ND filter costs reasonable compared to larger thread sizes.
Does it maintain f/2.8 across the entire zoom range?
Yes, constant f/2.8 from 18mm to 50mm. That's genuinely rare in a compact standard zoom.
SpecificationValue
Focal Length18-50mm
Max Aperturef/2.8
Min Aperturef/22
MountLeica L
Lens Groups10
Lens Elements13
Filter Thread55mm
Minimum Focusing Distance4.8" / 12.1 cm
Angle Of View76.5° to 31.7°
Length2.9" / 74.5 mm
Maximum Diameter2.5" / 64.5 mm
Package Weight1.015 lb
Box Dimensions5.4 x 4.2 x 4.1"
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 Leica L-Mount
Lens Type Standard / Normal
Max Focal Length 50mm
Min Focal Length 18mm