Sigma EX 20mm F1.8 DG ASP RF Review
General information
This is a prime lens manufactured by Sigma and the lens was released 2008.
The lens belongs to the category
wide angle prime lenses, a wide angle lens where you do not have the possibility to zoom in and out.
Product description from Sigma
At launch 2008 Sigma wrote this regarding Sigma EX 20mm F1.8 DG ASP RF:
"This Sigma 20mm F1.8 EX DG Aspherical RF is a unique Sigma offering with an aperture of F1.8 making it the fastest super wide angle lens available from any camera or lens manufacturer. For the scenic or landscape photographer it’s important to have a wide angle lens with excellent optical performance and Sigma’s aspherical lens technology provides high quality images for the serious shooter. Sigma’s 20mm lens has a field of view of 94.5º and yet provides for a close focusing lens-to-subject distance of only 2.6 inches. Such performance parameters provide great creative freedom to the photographer who wishes to exploit its capabilities for juxtaposing very near subject with the surrounding background. This extreme wide angle view also makes this lens ideal for crating “stitched” panoramic scenes for dramatic effect. The architectural photographer will find this lens attractive for shooting building interiors and the photojournalists will find its fast speed a life saver in low light conditions.
Designed for use with full frame digital cameras
May also be used with smaller APS-c size sensors
Two Aspherical glass elements offer correction for distortion
Minimum focusing distance of 7.9 inches allows close-up photography with a lens to subject distance of only 2.6 inches providing a magnification ratio of 1:4
Rear focus system eliminates front lens rotation & is suitable for use of Petal-type lens hood & polarizer filters
A lens hood, front/rear lens cap and carrying case are included with the lens."
Compatibility, autofocus and focal length
The lens is available for both Canon and Nikon cameras, but there are two different versions of this lens (one for each brand and mount) so it is important that you ask for and choose the right version when bying the lens.
This lens is constructed to fit all models of Canon and Nikon cameras, regardless of camera model or type of sensor.
Here it is the only Canon version of the lens that has a built-in autofocus (AF) motor. The possibility to use autofocus (AF) is available for Nikon cameras but only if the camera itself has a built-in autofocus (AF) motor. Some cheaper and budget camera models from Nikon lacks a built-in autofocus motor, and we at Lensora appreciate autofocus, so in the list of compatible cameras we have chosen to display only the cameras that you can get autofocus with.
The lens has a focal length of 20 mm. Depending on which camera the lens is used, the experienced and perceived focal length will be different. Please visit the list of compatible cameras below, it will provide the equivalent focal length you get on each camera.
- See compatible cameras and perceived/equivalent focal length
- See a full camera compatibility chart for Sigma EX 20mm F1.8 DG ASP RF
- Read more about focal length and your field of view
- Read more on the cameras impact on the perceived focal length
- Read more about the autofocus motor and the importance of this part
Lens brightness and image stabilizer
The lens brightness and aperture value is f/1,8.
This aperture value indicates that the lens is extremely bright. This will make it so much easier shooting in darker environments where you do not want or can use flash lighting, for example in churches or at different sports venues.
The lens lacks image stabilization, which otherwise os good for avoiding the blur that can occur when using slow shutter speeds. Since the lens is bright, with good aperture value, the lack of image stabilization might not be that big of a deal, although a image stabilizer is always an advantage to have.
Filter and Lens Hood
The lens has a traditional filter thread on the front and its measuring 82 mm which also the filter you will use must have. If you use for example an UV filter can be a cheap insurance against scratches and dust.
If you buy this lens it will come with a lens hood, whose model name is "LH875-02 548".
Images of Sigma EX 20mm F1.8 DG ASP RF
In order to see larger product images of the lens, click the link below.
Things to consider before buying
Below you will find some summarized points and facts that can be considered as the 'pros and cons' of this lens. These are based entirely on the facts and values that are accessible through the lens specification, so we highly recommend that you also read the reported reviews available (see tab 'Reviews'); this in order to get a more complete view of the lens and its capabilities. Reviewer opinions reflect the lens, its use and its optical performance in a more accurate way, but any way - here a few different points to consider before buying this lens.
- The lens brightness, f/1,8
- Works on all sensor types
- A lens hood is included
- No built-in autofocus motor (the Nikon version)
- The lens is not sealed against moisture and dust
- Heavy (520 gr)
Our Review Ratings
Time to grade Sigma EX 20mm F1.8 DG ASP RF.
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| Overall rating | 3 of 5 |
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