The lens despite its apparent size in most of the pictures isn’t really all that huge. Its wide, very wide, but it isn’t all that long at only 69mm, about an inch longer then a 35mm f/2 and approximately the same diameter as the Zuiko 18mm f/3.5 with its accessory filter hood attached. It is however quite a bit heavier then either of those lenses at 430g (compared to approximately 250g). The lens is an internal focus design, so nothing rotates or moves externally when you twist the focus ring. The focus ring is reasonably well damped if you turn it slowly, but it feels ‘poor’ if you turn it quickly (not enough resistance and not smooth feeling). It is accurate enough, just not very high quality feeling. The aperture ring is the same way, good positive clicks, but not much in the way of smoothness in turning it like you have with Zuiko lens, rather plasticy feeling like all Sigma lenses seem to have with their aperture rings.
The results I found were interesting. The lens does produce some distortion which isn’t that suprising with a 14mm rectilinear lens. It appears to be slightly wave form with an emphasis on barrel distortion that tapers off near the edges. Probably not too hard to correct with software and not that unacceptable with no correction. The lens is very, very, very sharp in the center of the frame. Maybe my sharpest lens surprisingly. Near the edge the sharpness/resolution is much lower, plenty acceptable wide open and sharpening up stopping down, but it never gets to really sharp along the edge even at f/11.
As with all my tests, 3200dpi on an Epson 4470, no sharpening, no ICE, no color correction or anything else. Tripod mounted, MLU and cable release. As a note, the camera was sitting probably about 1.5 feet from the bookcase (tripod foot was about 3 inches from it) to get around the same 1:30 reproduction size that I use for most of my tests. WIDE angle. Click on the images for the full size.
In the center things sharpen up a hair going from f/3.5 to 5.6, but anything further on is pretty indistinguishable. I’d say f/3.5 in the center is an B+, A at f/5.6 through 11.
On the edge things are still just fine, but not quite as sharp as the center. At f/3.5 I’d say is a C+ and f/5.6 on its a B, maybe a B- at f/11, but the exposure was 4 sec using a cable release with the camera set to bulb and no stop watch, not the most accurate way to get exposure, so I am giving f/11 the benefit of the doubt that it is just as sharp as f/8.
A couple of final notes about the lens. You cannot mount front filters to it. The rear of the lens has a gel filter mount and has a template to cut gels to size to fit in the rear filter mount. At a guess I’d say that the rear gel filter holder is probably 22.5mm in size. You could easily get several gel filters cut out of a standard gel. I haven’t had much outdoor use of the lens so far since getting it. That said flare does look like it is going to be a constant companion for this lens. I want to try shooting into the sun and with the sun near the edge of the frame and just out of the frame, but padding around my house at night with bright lights on you get a bit of flare, but little or no veiling flare with bright lights just out of the frame (and not blocked by the hood). With bright lights in the frame flare is pretty much non-existant. The flare is not overly obtrusive.
I’ll try to come back and update the page when I have a chance to use the lens more extensively, but so far my opinions on the lens are very, very positive. It might not be a Canon or Nikkor 14mm f/3.5, but this is a really nice 3rd party super wide angle lens that really gets the job done. Other then being unobtanium for me for the better part of a year I bought this lens for interior architecture and all/big sky landscape photos. A bit of a lesser emphasis on tight quarters architecture shots, such as in big cities. This lens is going to prove to be very, very useful for taking real estate photos for when my wife and I sell our house, hopefully later this year. A final parting thought, f/3.5 isn’t overly bright, but with a 14mm focal length you can handhold at 1/15s if your careful enough (and slower if you’re really steady), that makes it the equivalent to a 50mm f/1.8 for handholding ability for low light (1/60s at f/1.8 compared to 1/15s at f/3.5). Also, looking at the DOF scale with its f/4, 8, 11, 16 and 22 marks if you focus at 1m everything from approximate 1ft to infinite is in focus at f/16. The lens is a tight fit in my Lowepro Nova 2 AW because of its large diameter, but it’ll fit, just, and still be able to fit lenses on either side of it. It’ll definitely find a home in my camera bag anytime I am heading out for landscape pictures or the next time I head to Europe (whichever decade that might be in). Not really a backpacking lens, the Zuiko 24/2.8 will just have to do for that on the wide angle.
Here is an example photo with the lens, taken in my guest bath which measures 5ft wide and 9ft long. This is why the lens is going to be very, very useful for real estate interior photos of my house.
This shot was taken perhaps 2ft away from my wife.