The Sigma 19 mm f/2.8 EX DN E is a third party, wide angle prime for APS-C E mount cameras. It is Sigma’s counterpart to the Sony SEL20F28 pancake and often said to actually be the superior lens of the two.
The Sigma is still light, but considerably heavier than the SEL20F28. Autofocus is fast and build quality is very good, although the lens feels a bit plasticky. Handling on a NEX-5T is a generally very good, too. Manual focus and focus override are a pleasure to use because the lens reacts very fluidly and precise to any input. The effective focal length of 29 mm on APS-C cameras makes the Sigma an excellent performer for reportage-style photography, videography and landscape shots.
Condition of my copy
Optics: Excellent. No scratches, no dust – new.
Mechanics: Excellent. Focus ring uniform, aperture clean and fast.
Exterior: Excellent. Like new.
Optical performance on NEX-5N / 5T
The following evaluation is based on uncorrected RAW images. Please keep in mind that all native E mount lenses are electronically corrected in camera (vignetting, distortion, CA) and JPEGs of these shots therefore look very different.
The lens starts at f/2.8 with very good central sharpness and only minimally soft corners. At f/4, corner performance improves to good and central sharpness reaches absolutely outstanding levels. The image stays mostly unchanged up to f/8 with excellent sharpness and contrast. Diffraction becomes visible at f/11, is pronounced at f/16 and strongly softens f/22.
There are no visible CAs at any aperture. Either this is an excellently corrected apochromatic lens, or the electronic retouching of CAs in-camera cannot be deactivated.
Vignetting is about 2/3 of a stop at f/2.8, actually seems to deteriorate at f/4, but is gone by f/5.6. This is certainly a mistake in the test shots and likely caused by local shadowing due to “human interaction” (I may have stood between the chart and the lamp). Apart from this little oddity, the lens exhibits a medium barrel distortion of -0.9%. The effective T-stop at f/2.8 is T3.2 (-0.4 EV), which is okay for a prime.
Compared to Sony’s SEL20F28, the Sigma really stands it’s ground. While central sharpness is about equal at all f-stops, the Sigma shows consistently better corner performance. Less vignetting and distortion in RAW images are further advantages. And all that at about half the price of the Sony! The main compromise you have to accept is the size difference, with the Sigma being about twice as long as the ultra compact SEL20F28. You also loose a bit of AF speed in direct comparison, but this shouldn’t be a dealbreaker as the Sigma is still reasonably fast.
The following images are pixel-level crops from the test chart. They may appear scaled in your browser window. Click on them to view the crops in full size and cycle through them easily. For more info on the test setup, visit the details page.
(Cropped areas marked in orange)