Sigma
Sigma 20mm f/1.8 EX DG RF Wide Angle Lens
★★★★★
f/1.8
Capture Expansive Views with Precision OpticsThe Sigma 20mm f/1.8 EX DG RF Aspherical Wide Angle Lens delivers exceptional image quality and sharpness for Sigma SLR cameras. With a wide aperture of f/1.8 and a minimum focusing distance of 20cm, this lens is perfect for capturing stunning landscap...
$899.00*
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*Price sourced from Amazon.com. Last updated:Jul 15, 2026.Price and availability are subject to change.
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Overview
Capture Expansive Views with Precision Optics
The Sigma 20mm f/1.8 EX DG RF Aspherical Wide Angle Lens delivers exceptional image quality and sharpness for Sigma SLR cameras. With a wide aperture of f/1.8 and a minimum focusing distance of 20cm, this lens is perfect for capturing stunning landscapes, interiors, and astrophotography.
Specifications:
- Minimum Focusing Distance: 20cm
- Aspherical Lens Elements: Incorporated in front and rear lens groups
- Maximum Magnification: 1:4
Key Features
This lens has a minimum focusing distance of 20cm
Incorporated aspherical lens elements are used in the front and rear lens groups
The lens has a maximum magnification of 1:4
Specifications
Focal Length
20mm
Maximum Aperture
f/1.8
Minimum Focusing Distance
20cm
Maximum Magnification
1:4
Lens Design
Aspherical Lens Elements (Front and Rear)
Pros & Cons
👍 Pros
- Features a wide 20mm focal length, ideal for capturing expansive landscapes or interiors.
- Offers a very fast f/1.8 maximum aperture, allowing for excellent low-light performance and shallow depth of field.
- Incorporates aspherical lens elements in both front and rear groups to minimize aberrations and enhance image quality.
- Achieves a minimum focusing distance of 20cm, enabling close-up shots with a wide perspective.
- Provides a maximum magnification of 1:4, which is useful for capturing detailed subjects in a wider frame.
👎 Cons
- As a prime lens, it lacks the flexibility of a zoom, requiring physical movement to change perspective.
- The f/1.8 aperture, while fast, can lead to very shallow depth of field that might be challenging to manage for some photographers.
- Being an older "EX DG RF" series lens, it may not feature the latest optical designs or autofocus motor technologies of newer Sigma lines.
- The wide angle and fast aperture can make it a specialized lens, potentially not suitable for all types of photography.
- Autofocus speed and accuracy might not be on par with more modern lens designs.
Frequently Asked Questions
What is the focal length of this Sigma lens?
This Sigma lens has a fixed wide angle focal length of 20mm.
What is the maximum aperture available on this lens?
The lens features a fast maximum aperture of f/1.8, beneficial for low-light conditions.
What is the closest distance this lens can focus?
This lens has a minimum focusing distance of 20cm.
Does this lens use special optical elements?
Yes, it incorporates aspherical lens elements in both the front and rear lens groups.
What is the maximum magnification ratio of this lens?
The lens offers a maximum magnification of 1:4.
Is this a zoom lens or a prime lens?
This is a prime lens with a fixed 20mm focal length, meaning it does not zoom.
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