Photo Jottings

Full review of the Sigma NEX 19mm F/2.8 EX DN lens. 

Box and contents

The Sony NEX-C3 was used for this review.  For a better understanding of terms and methods used in this review, go here.

The usual center, mid-section and corner crops are located at the very bottom of the page.

The Sigma NEX 19mm F/2.8 is one of two new Sigma prime lenses (announced in early 2012) designed for use with the Sony NEX and micro 4/3 system, the other lens being a 30mm, F/2.8, also reviewed here.  Both these focal lengths are odd choices by Sigma for APS-C cameras in my opinion, and they don’t make any better sense in 4/3 either.

 

Sigma claims the 19mm F/2.8 EX DN (digital neo) telecentric optical lens has three glass molded aspherical elements, and super multi-layer coatings to reduce flare and ghosting.  Sigma’s choice of a 19mm F/2.8 lens is baffling.  The focal length is about 28mm in 135 film format, and F/2.8 is not fast for a prime lens.  Most Sony zooms start at 16-18mm, F/3.5, so the additional speed is marginal at best.  Sigma omitted ‘OSS’ or optical stabilization, probably to keep the price down.  For this lens to be of any value, it’s going to have to work very well at F/2.8, otherwise, what’s the point!

 

Fit and finish are very good.  The lens appears to be clad in high quality plastic with a metal mount.  The lens is made in Japan, and is written in big letters around the front element!!  I guess Sigma is proud they didn’t offshore it.  When shaking the lens, it sounds like something is loose inside, and in fact the middle group is just floating around in the center of the lens, but when it gets power from the camera, it stays put; this procedure also takes a couple of seconds, and lengthens the start up time, the owners manual alludes to this.  Available in Silver or black.

 

Budget lens reality; Sigma basically says in the manual that sending the lens in for repair from water or other damage is a waste; in other words, when the lens fails for whatever reason, unless covered under the warranty, throw it away.

 

Filter size is 46mm, which is a clear nod to Panasonic and Olympus that have numerous micro 4/3 lenses using this size.  Unfortunately, Sony makes no lenses with this filter size, so you might have to get a step-down ring to mount your 49mm filters.

In the box is the lens, front and rear caps, small plastic solid hood, a padded softcase and owner’s manual.

Requisite product shots.

Front element; notice the MADE IN JAPAN label!

Back side

General information and specifications.

Lens flare/ghosting.  Below average to poor control, see examples below.

Light fall-off.  Nothing to worry about.  See samples below.

Color fringing (CA).  Average control.  I see mostly purple along the sides of the image at high contrast edges.  I notice no axial type.

Bokeh.  Rough or smooth, it depends on background distance.  See crops below.

Color.   Seems about the same as Sony lenses.

Close-up filter.  Works ok, +4 tested.

Coma.  For pixel peepers, a tiny amount at F/2.8.

Regular filters: probably don’t cause any additional light fall-off, however, I didn’t test this as I don’t have any 46mm filters.

Filter size.  46mm.  No Sony or Minolta lenses use this size, Sigma used it for the micro 4/3 system which has plenty of lenses already using 46mm.

Distortion.  Mild to moderate barrel with a slight wave.

Distortion example directly below.

Mild to moderate barrel distortion

 

The distortion pattern is barrel, with a very slight wave.  Distortion correction sliders are able to almost eliminate it.

 

 

Bokeh samples.

 

 

Bokeh looks pretty smooth when the subject is close, say around 3′-6′ (1-2m), and the background is much farther away, like 20′ (6m) or more, see top row.  However, when the subject and background are close together, like 15′ (3m) to the subject, and 25′ (8m) to the background, bottom row, the background highlight blur can look busy, especially stopped down.  Remember; bokeh is the character of out of focus highlight blur, not just parts of the image that aren’t in focus.

 

 

Light fall-off

 

Flare and ghosting control is well below average to poor; I see magenta streaks and loss of contrast when the sun is in the image, or just outside the image.  Lowering the exposure hides some of this.  There are a few small colored blobs that show up in bright conditions, especially green.  Viewing your images on your camera screen may not show this stuff, it’s much more noticeable when you get home and look at the pictures on a larger screen.  Use the included hood for this lens, and a hand shield anytime the sun is close to the front element, otherwise you’ll be sorry.

Lateral color fringing is noticeable along the sides of the image, this is about as bad as it gets.  Some cameras will automatically remove this, so you won’t see it.  This crop is from the last 700 pixels of the image at the middle right side.  Also see the corner crops at the bottom of the page.

As close as you can get, F/5.6.

The Sigma 19mm F/2.8 lens has some nice qualities; it’s relatively inexpensive, small, lightweight and performs very well at F/2.8!  It would be great as a low-light video lens, or for people shooting night scenes without a tripod.

Optically, this lens rates high on my scale for center and mid-section sharpness, especially at F/2.8, distortion is well controlled, and focusing accuracy most of the time is as good as the Sony NEX prime lenses.  Disappointments include soft extreme sides, flare control and no optical stabilization.

Overall, the Sigma 19mm F/2.8 lens is a good lens, but is it better than the kit 18-55mm or 18-200mm zooms from Sony at 19mm, or around that length?  The short answer is; if you’re a snap shooter during daylight, the kit lenses are a much better choice; they’re more useful than a prime because you’re not stuck at 19mm.  I don’t have the Sony 18-55mm or 18-200mm with me at the time of this review, but I don’t think there’s a whole lot of difference in sharpness at the same focal length when using smaller apertures like F/5.6-8.  If 19mm is your focal length, and you like to shoot in low-light with no tripod, the Sigma 19mm would be a great choice as it’s sharp through most of the frame at F/2.8.

People using the 4/3 system may get even better performance as the extreme sides will be cropped out as a result of the lens’ larger APS-C image circle.

Landscapers using the Sony NEX 16mm F/2.8 will see much sharper mid-sections with the Sigma 19mm, at the cost of a little longer focal length and portability.