Tamron has recently released the first full-frame-compatible ultra-wide-angle zoom to have a fast f/2.8 constant aperture and built-in image stabilization, the SP 15-30mm f/2.8 Di VC USD Lens. I was asked to test the lens for this review, so I mounted it on my Canon 6D to really see what it is capable of—and I can say, right off the bat, that I was very impressed.
First of all, the SP 15-30mm f/2.8 Di VC USD Lens is huge. It has a solid feel and a rubber seal around the mount that will protect the camera from stray rain and snow. One thing I noticed was air movement when I zoomed the lens, which makes me a little more cautious during the snowy days we've been having here in New York City, but I wasn't particularly worried.
 |
 |
| 15mm | 30mm |
The lens offers an ever-so-slightly wider focal-length range of 15-30mm, compared to the standard 16-35mm, which may impact some shooters who come to rely on the 35mm focal length. Personally, I was wishing for a little bit of extra zoom during one shoot, so diehard 16-35mm lovers should keep this in mind. On the other hand, this setup is very well suited to landscapes and architecture, and the image stabilization allows for practically shake-free imagery during video shooting.
Of course, the most important feature of any lens is its optical performance, where I was constantly surprised by this lens. The main things to watch out for with ultra-wide-angle lenses are distortion and vignetting. At 15mm, there is very noticeable barrel distortion, which slowly disappears as you zoom in, but when you reach 30mm, there is a slight pincushion as you can see in the following series of images. Vignetting can also be a problem, with a very dramatic drop-off when wide open at f/2.8, which slowly corrects itself as you stop down. It doesn't appear to vanish completely, but it does become a non-issue around f/5.6 to f/8, which also happens to be the setting for optimal sharpness.
 |
 |
 |
 |
 |
 |
 |
| 15mm f/2-8 | 15mm f/4 | 15mm f/5-6 | 15mm f/8 | 15mm f/11 | 15mm f/16 | 15mm f/22 |
 |
 |
 |
 |
 |
 |
 |
| 30mm f/2-8 | 30mm f/4 | 30mm f/5-6 | 30mm f/8 | 30mm f/11 | 30mm f/16 | 30mm f/22 |
Vibration Compensation, or image stabilization as it is more commonly known, is one of the highlights of this lens. And, I can report, it works very well. While the following images aren't ideal examples for demonstrating the potential of the system, they can show how the image stabilization can easily turn an unusable image into a very usable one. If you have very good technique or something to help brace your grip, you can easily utilize shutter speeds upward of 1 second. Video shooters especially will appreciate the quality of the image stabilization, and with such a wide focal length, shooters will be able to produce exceptionally stable-looking footage.
 |
 |
| VC Off | VC On |
In practical terms, the 15-30mm performs admirably. While the barrel, perhaps, doesn't have the feel of top-tier options like Zeiss or Schneider, it does feel like it can take a few hits and keep going. Also, the focus ring is placed behind the zoom ring for excellent balance while shooting. The ultrasonic drive motor (USD) enables quiet, accurate focusing, especially since the super-wide focal length isn't extremely demanding when it comes to hitting focus. One thing for videographers to note is the slight breathing effect when adjusting focus.
The bulbous front element has a fluorine coating to repel water and grease and it has a zoom-linked double-hood design that both prevents stray light from striking the lens and minimizes potential damage from impacts. The front elements move physically back and forth as you zoom, to provide better shading from light, depending on the focal length. One drawback of this design is that it will not accept standard front-threaded filters, and this lens doesn't have any sort of insert-type holder for gels or alternative filtration.
Shooting with the lens feels good and the images are sharp, even wide open at f/2.8. Wide-angles usually struggle with sharpness, wide open, because of their focal length. The lens is sharper at 15mm than it is at 30mm, but the wider end is the more important side to focus on, as most photographers will have other lenses to cover the 24-35mm lengths. Also, even when stopped down from f/11 to f/22, diffraction doesn’t appear to have a huge impact on the sharpness of the image, although f/5.6 to f/8 is the sweet spot.
With a close focus distance of 11" and a maximum aperture of f/2.8, it is still possible to get good subject-background separation with shallow depth of field. The out-of-focus elements are enhanced by the use of nine rounded aperture blades, which produce smooth image quality. Also, when stopped down, the blades create excellent starbursts with numerous points.
Flare is exceptionally well controlled with the use of both BBAR (Broad-Band Anti-Reflection) and eBAND (Extended Bandwidth & Angular-Dependency) coatings. Even with lights directly in the scene, I never experienced any shot-ruining flare or ghosting. Chromatic aberrations are practically nonexistent, with the use of Low Dispersion and a large diameter XGM (eXpanded Glass Molded aspherical) elements.
Overall, I was quite impressed with the performance of this lens in all aspects, which is incredible for a lens in this class, especially the sharpness of the lens at f/2.8 and the inclusion of Vibration Compensation to smooth out longer exposures and video. There were some slight issues with distortion and vignetting, but nothing unexpected. For anyone looking for a fast, affordable, ultra-wide angle zoom lens, this will be a hard lens to beat.
The Tamron SP 15-30mm f/2.8 Di VC USD is available in Canon EF, Nikon F, and mounts.