Sigma 19mm f/2.8 EX DN for Micro Four Thirds and Sony NEX Lens Review Roundup

On January 10 2012, Sigma announced the 19mm and 30mm f/2.8 EX DN fixed-focal-length lens for Micro Four Thirds (MFT) and Sony NEX cameras. The 19mm lens is comprise of 8 elements in 6 groups, an angle of view of 59.3 degrees on Micro Four Thirds and 73.5 degrees on an E-mount camera. This 19mm lens benefits from a newly developed linear AF motor which moves the lens elements directly without the need for gears or the drive of other mechanical parts, and comes with a non-rotating 46mm filter thread. It features a rounded 7 blade diaphragm creating an attractive blur to the out of focus areas of the image, a minimum focusing distance of 20cm/7.9in and a maximum reproduction ratio of 1:7.4. 

In additions to the 19mm, Sigma also announces the 30mm f/2.8 EX DN lens for Micro Four Thirds (MFT) and NEX system camera. With an optical formula that comprises 7 elements in 5 groups and an iris diaphragm with 7 rounded blades, the Sigma 30mm f/2.8 EX DN has an angle of view of 39.6 degrees on MFT and 50.7 degrees on an E-mount camera, thus being equivalent to a 60mm and a 45mm lens, respectively. The lens benefits from a newly developed linear AF motor which moves the lens elements directly without the need for gears or the drive of other mechanical parts, the company says. Note that this is not a macro lens - the maximum reproduction ratio is only 1:8.1. The Sigma 30mm f/2.8 EX DN has a non-rotating 46mm filter thread and weighs in at 135 grams. Here's the 19mm lens technical specifications:

The Sigma 19mm f/2.8 EX DN lens is currently selling at around $219, via Amazon.com [MicroFourThirds-mount] [Sony-mount]. Here's the lens review roundup:

m43photo: "First of all, just like its sister lens the Sigma 30mm, this lens rattles. Something is loose inside the lens when it is not in use. This is a bit annoying, but no problem. Once the lens is connected to a camera, and the camera is turned on, the rattling stops. There is a small start-up delay when powering on the camera, unlike most other lenses. The delay is around 1.5 seconds, shorter than for the Sigma 30mm lens. The autofocus is fast and virtually inaudible. Here is an autofocus speed comparison with the Lumix 20mm f/1.7 pancake lens. As expected, the 19mm lens focuses much faster. There is also a big difference when using the lenses for video. Here is a side by side comparison with the 20mm lens, which shows much better performance when using the 19mm lens. Both lenses are set to f/2.8:

While the Sigma 30mm f/2.8 gave a good value for money in terms of optical performance, the Sigma 19mm can be seen as more lacking. And with the Lumix G 20mm f/1.7 outperforming the Sigma 19mm, it is hard to recommend the Sigma lens, unless you are on a tight budget, or if autofocus performance during video is important to you. The Sigma 19mm lens is not bad, far from it, it just doesn't reach up to the Lumix G 20mm lens, or the sister lens, the Sigma 30mm f/2.8."... [Source]

PhotoZone, gave an optical quality rating of 2/5: "The resolution characteristic of the Sigma AF 19mm f/2.8 EX DN is a bit on the odd side. On the one hand we have an exceptionally high center performance straight from f/2.8 onward. The lens is capable of keeping this level all the way to f/8. On the other hand the borders and more so the corners are weak especially at f/2.8. Stopping down helps, of course, but the quality does not exceed good levels here. The centering quality of the tested sample was good and there's only a slight degree of field curvature. The Sigma lens produces a quite high amount of lateral CAs (color shadows at harsh contrast transitions) with an average pixel width of around ~1.7px at the image borders. This will be visible in certain scenes but remember that this can be corrected during image post-processing.

The Sigma AF 19mm f/2.8 EX DN shares a couple of characteristics with its sister lens, the Sigma AF 30mm f/2.8 EX DN, but it doesn't reach the same level of performance. The center quality is absolutely great for sure but the outer image regions are soft at f/2.8 and reach only good levels at medium aperture settings. The pronounced lateral CAs don't help either in terms of subjective quality perception. There's a moderate degree of barrel distortion but this is rather typical for such wide-angle lenses. The vignetting could be a little lower but it is nowhere extreme. The bokeh (out-of-focus blur) is pretty decent except for a slightly nervous highlight rendition. The build quality of this little prime lens is surprisingly good. Thanks to an internal AF the physical length remains constant and the manual focus action feels smooth and without wobbling whatsoever. Sigma's new linear AF motor is both speedy as well as silent. The Sigma AF 19mm f/2.8 EX DN has certainly an edge over its obvious competitor - the Sony E 16mm f/2.8 - so if you are feeling an itch for compact primes it may be a reason to go for it. Price/performance-wise it is just an average offering though."... [Source]

SLRgear: "The lens provides sharp images, more so on the micro four-thirds camera than on the Sony NEX, owing to the fact that the micro four-thirds sensor does not "see" the corners of the lens. Mounted on the Panasonic GX-1 m4/3 camera, the lens produces excellently sharp images even wide open at f/2.8. There's just a hint of corner softness at f/2.8, but even this is all but eliminated by just stopping down to f/4. Stopping down to f/5.6 technically provides more sharpness, but you'd only notice it looking very closely at a test chart. Diffraction limiting sets in at f/8, but you won't notice any impact on sharpness until f/16, where it is still very sharp across the frame. Fully stopped-down at f/22, there is some impact on sharpness, but it's still very good. Mounted on the Sony NEX-7, the lens follows the same pattern of sharpness - very good at f/2.8, excellent at f/4 to f/8, and softer at f/16 and f/22. In this case however we note softer corners than seen on the GX-1, owing to the larger sensor being viewed by the lens. Chromatic aberration is notable with the lens attached to both camera bodies: on both bodies, it's viewed in the corners, in areas of high contrast. In images shot with the Panasonic GX-1, it appears as magenta-green fringing, and in images shot with the Sony NEX-7, it appears as magenta fringing. It gets marginally better with either camera if you stop down, but only slightly. 

The Sigma 19mm f/2.8 EX DN is a fairly pedestrian lens, small and light with a matte black finish. The lens is made of primarily plastic components, weighing only 140 grams (4.9oz), with plastic 46mm filter threads and a metal lens mount. The lens has only one control on it, the manual focus ring. There is no depth-of-field scale, distance scale or infrared index. There are a surprising number of alternatives in this category - wide primes for mirrorless cameras - so Sigma's offering comes at an interesting time. It holds its own in our tests, providing a sharp image even wide open at f/2.8, with only slightly notable chromatic aberration in the corners. It's not a case of Sigma finding a niche other manufacturers haven't exploited, however, Sigma does undercut all the current manufacturers with a lower price point. If you haven't got a wide angle prime for your micro four-thirds mirrorless camera, or your Sony NEX camera, then you may want to consider the Sigma 19mm f/2.8 DN."... [Source]

PhotographyBLOG, gave a rating of 4/5: "The Sigma 19mm f/2.8 EX DN isn't claimed to be a macro lens, but it delivers a pretty good performance nonetheless. It has a minimum focusing distance of 20cm/7.9in and a maximum magnification ratio of 1:7.4. The following example demonstrates how close you can get to your subject, in this case a Compact Flash memory card. Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc. In the Sigma 19mm f/2.8 EX DN lens, Sigma employed an iris diaphragm with seven rounded blades, which has resulted in nice bokeh in our view. We do realise, however, that bokeh evaluation is subjective; so we've included several 100% crops for your perusal. For this test, the Sigma 19mm f/2.8 EX DN lens was attached to a Panasonic Lumix DMC-GF3 body, which in turn was mounted on a sturdy tripod. Exposure delay mode was activated. Tonal and colour variances across the crops are due to changes in natural light during the session. Centre sharpness remains high through from f4 to f/11, with f/16 and f/22 being adversely affected by diffraction. The edges aren't nearly as sharp as the centre, with f11 producing the sharpest results.

For the modest financial outlay, the new Sigma 19mm f/2.8 EX DN lens is definitely worth considering, especially for Sony E-Mount users looking for an affordable wide-angle lens. It's less attractive for Micro Four Thirds owners, though, with smaller rivals from Panasonic and Olympus available that deliver better image quality, although the Sigma offering undercuts them all in terms of value. It may not be the smallest, fastest focusing or best-performing compact system camera lens, but it does hit an attractive price-point without having to make too many compromises."... [Source]

ePhotoZine, gave a rating of 4.5/5: "Sharpness in the centre of the image area is already outstanding at maximum aperture and the clarity towards the edges is very good. Stopping down the lens improves sharpness towards the edges further, with peak quality across the frame being achieved between f/5.6 and f/8. Chromatic aberrations are reasonably well controlled, just exceeding 0.75 pixel widths towards the edges of the frame at f/5.6. This low level of CA should pose few issues, even in large prints, or harsh crops from near thee edges of the frame. Falloff of illumination towards the corners of the frame is reasonably well controlled for a wide aperture lens. At f/2.8 the corners are 1.08 stops darker than the image centre and visually uniform illumination is achieved by f/5.6. Imatest detected 1.1% barrel distortion, which is a relatively high amount for a fixed focal length lens, although this should still be a low enough level of distortion to pose issues day to day. The distortion is uniform across the frame, so it should be quite straightforward to correct in image editing software if absolutely straight lines are required.

A circular lens hood is supplied as standard, and this lens proved itself quite resistant to flare in testing. When shooting into the light, some flare may appear, but only in extreme circumstances and contrast remains good. This compact lens should make an ideal addition to any Micro Four Thirds or Sony NEX camera kit. Its light weight, compact size and excellent optical performance are complimented by fast auto focus speeds and good build quality. With the price sitting at around £170, this lens represents excellent value for money also."... [Source]

User review by P. Snyder, gave a rating of 4/5: "Good sharpness across the frame. Fast and accurate AF with very quiet operation. A very good bargain 38mm equivalent for your MFT. The focusing ring is easy to use in MF assist/focusing by wire when filming. A good buy. Not as sharp as a Leica or Zeiss lens but it is quite good especially for the money. Also not alot of distortion or flare or internal reflection from what I could see in the files I have made thus far. I personally really like this focal length for MFT. A good cheaper option to the 20 1.7 by Panasonic or Leica 25mm DG 1.4. Both are however a tad sharper and certainly faster. But they are 2X to 3x more $$$ too. Lastly bokeh is quite good for a 19mm. It is still 19mm afterall folks;-)! It is a nice small lens. I will use this and the anticipated 17mm 0.95 Voigtlander (once I get it in May) for probably 80% or more of my filming."... [Source]

Phoblographer: "Here's something you should know about both lenses: they're both not extremely small and won't make your camera super pocketable. But they're not extremely large either and instead feel very balanced on the camera body. The 19mm f2.8 even includes a lens hood. They both feature large manual focusing rings and no distance or depth of field scale. In practice, that's a bit of a bummer for street photographers who love to manual focus. For the Sony NEX crowd though, your cameras have peaking for focusing; so it won't be as bad for you.

Focusing for the most part is fairly snappy, but not as fast as Olympus's MSC lenses. However, there were some issues with the 30mm f2.8. On either one of my camera bodies, I would sometimes focus, not be happy with what I got, and then try to refocus. When this processed repeated itself to around three times, it would freeze the lens and the camera would not take a photo until maybe around 20 seconds afterward. The only way around this problem was to physically take the lens off and shake it around. Indeed, I even heard the elements inside moving around. As an extended note, the issue seemed to have been gone when I got home as I tried it and gave the lens quite the focusing stress test on both cameras later on. I didn't experience this problem with the 19mm f2.8 and I'm willing to consider the fact that the lens may have taken a bump in the pillow fight, but I highly doubt it. I protected the cameras very well. If anything, it's my glasses that took the bump as I almost lost them."... [Source]