Sigma 19mm f/2.8 on the NEX-7.
This is a follow up to my review of the Sigma 30mm f/2.8 lens for the Sony NEX. This time, I am testing the Sigma 19mm f/2.8 pancake.
The Sony NEX platform is still relatively new on the market and the lens range is still relatively modest, so I was quite excited to hear that Sigma announced two new primes for the NEX mount, a 19mm and 30mm f/2.8. This is a review of the 19mm, which gives the same angle of view as a 28mm on a full frame 35mm camera. Sigma is at present the only third party lens manufacturer producing primes for the NEX mount.
The lens comes in a dark gray finish (a tad lighter than the NEX-7 black and less shiny). It is delivered with lens caps and a lens case and a shade. The shade from the Sony kit zoom seems to fit at first sight. Filter mount diameter is 46mm. Diaphragm is 7 blades, but I have not tested the bokeh. Minimum focus distance is 0.2m (0.66ft) and, unfortunately for the video inclined, focus is quite louder than on Sony lenses. Focus is a tiny bit slower than the Sony 16mm, just as on the 30mm.
One may wonder what is the use for a 19mm prime lens when NEX cameras come with a 18-55mm standard zoom. The advantages are as follows:
•some photographer prefer prime lenses (I do)
•prime lenses are usually faster, this lens is almost a stop faster than the standard zoom at 19mm (which, frankly is not that much)
•prime lenses can be smaller, so called "pancake lenses" are of great interest for a system selling itself on size
•prime lenses are easier to correct than zooms and can therefore be sharper.
So is the Sigma 19mm f/2.8 that small? Here are some comparison views with the Sony 16mm f/2.8 pancake, the Standard NEX 18-55 zoom and the Sigma 19mm f/2.8. As you can see, it is more compact than the zoom but not as small as the pancake. The gain over the zoom is real, though. The 19mm is a bit longer than the 30mm.
|The 16mm, 30mm, 19mm and kit zoom together.||The same with hoods on.|
|The 19mm and Kit zoom with hoods reversed for storage.||The 19mm, hood and pouch.|
Here you see front and rear views:
|Front view, the diaphragm mechanics are visible in the 19mm.||Rear view, 19mm is on right side.|
What about optical quality, then? After all, the NEX platform already has the Sony / Carl Zeiss 24mm f/1.8, which is as big as the standard zoom and principally sells itself on aperture and quality. The Sigma is a fifth of the price, it does not have the f/1.8 aperture, but does it have the quality? Considering that the NEX-7 puts quite a strain on lenses with its 24 mpix resolution, what can we expect from a 200€ lens? Designing compact lenses for the NEX platform is not easy, because of the small registration distance. Is the lens sharp?
I ran the same test on the 19mm as I did on the 30mm, taking pictures of the city skyline and oriented it corner to corner, like this:
|Full image taken with the 19mm f/2.8|
The advantages of this simple test are explained in the review of the 30mm, let just say here that by examining the difference between the corners and the center, or the difference between the results at different apertures, or the difference between different lenses, we can see which lens is sharp and which lens is… less sharp. And where.
The lens is another the good surprise, especially for the price: at f/2.8 already, it is reasonably sharp corner to corner. I see a slight difference which disappear at f/8, but one really needs to peep pixel to tell. The lens vignettes a little bit wide open (quickly disappears when stopping down) and, like the 30mm, has a little bit of lateral chromatic aberration (which does not disappear when stopped down but is easy to correct), but apart from that it is close to be a perfect lens. Recommended.
For a comparison, you will find here corner crops of some 28mm lenses on the A900 taken at the same place a year ago (and with the horizon the other way round).
|19mm f/2.8 center crop at f/2.8||19mm f/2.8 corner crop at f/2.8|
|Minolta 28mm f/2.0 at f/2.8 on the A900||Minolta 28mm f/2.0 at f/2.0 on the A900|
|Carl Zeiss 16-35 at 28mm f/2.8 on the A900||Carl Zeiss 24-70 at 28mm f/2.8 on the A900|
You may download the full resolution pictures at f/2.8, f/4, f/5.6, f/8 and f/11 and a few sample pictures from my flickr account:
And if you are interested in 28mm full frame lenses on the A900 (same angle of view as the 19mm on the NEX and same resolution), you will find them here:
The views and opinions expressed in this article are those of the author and do not necessarily reflect the views and opinions held by dpreview.com or any affiliated companies.