Tamron 15-30mm f/2.8 Di VC USD SP

SLRgear Review
December 28, 2015
by Andrew Alexander

The Tamron 15-30mm ƒ/2.8 Di VC USD SP was introduced at the 2014 Photokina camera expo, and arrived on store shelves a few months later: we've finally pushed it through our queue in our test lab.

Tamron's made a good gamble with this lens, offering a full-frame ultra-wide angle zoom lens complete with image stabilization and a fast ƒ/2.8 aperture. There are some notable alternatives in this category, but nothing includes all of these features.

The lens employs a fairly complex design of 18 elements in 13 groups, with three LD elements, 2 stand ard aspherical elements and a special XGM aspherical element ("expanded glass mold"). It is available in Canon, Nikon and Sony Alpha mounts, but the Sony mount doesn't come equipped with image stabilization, as those cameras have their own in-camera I.S. system.

The lens has a built-in hood, does not accept filters (on the front or rear of the lens), and is available now for around $1,200.

Sharpness
As with most wide-angle lenses, the Tamron 15-30mm ƒ/2.8 excels when mounted on a sub-frame camera like the Canon 7D, where the image sensor doesn't "see" the corner performance of the lens. To wit: on the Canon 7D, the lens provides excellent results for sharpness, straight away from ƒ/2.8 and at any focal length. Stopped down to ƒ/4 the lens provides tack-sharp images across the frame.

On the Canon 1Ds mkIII, it's a little different, but not terribly so. The lens suffers in the corners at ƒ/2.8, and at 15-20mm. Zoomed in beyond 20mm, the corners are a little better, but the area of sharpness in the center is a bit sparse. The lens definitely benefits from being stopped down, and at ƒ/4 there's dramatic improvement in the corners, across the board. There's a little bit more improvement stopped down to ƒ/5.6, but that's about as good as it gets, and the lens never really achieves tack-sharpness when mounted on our Canon 1Ds mkIII, but its results are still excellent at ƒ/5.6 through to ƒ/11.

Diffraction limiting begins at ƒ/11, but you really won't see it until ƒ/16, where generalized softness descends on the image. The lens is capable of stopping down to ƒ/22, but it's not really recommended, as diffraction is robbing you of considerable sharpness at this aperture. Besides, for this lens, if you recall your hyperfocal distance calculation, you don't need to stop down excessively before everything in the frame is in focus.

Chromatic Aberration
It's noticeable in the corners with this lens, but not overly so - if you peep your pixels, you'll see it in areas of high contrast, showing up as a cyan/magenta color shift. It's similarly prominent mounted on either a sub- or full-frame camera.

Shading (''Vignetting'')
With the Tamron 15-30mm ƒ/2.8 mounted on the Canon 7D, we noted negligible corner shading - the only noteworthy point was at the 15mm focal length, where we see corners that are just 1/4 EV darker than the center.

On the Canon 1Ds mkIII however, it's a different story - at 15mm and ƒ/2.8, the corners are a full stop darker than the center of the frame. That's the most significant - any other setting is better. On average, you'll be looking at between 1/3 and 1/2 EV of corner shading, depending on your setting.

Distortion
Mounted on the Canon 7D, distortion is fairly tame, again, because the sensor can't see the edges of the lens. On the Canon 1Ds mkIII, there is some substantial image distortion. It's a prominent barrel distortion at 15mm, then as you zoom in towards 20mm it improves to negligible distortion. As you zoom beyond 20mm towards 30mm, you'll encounter significant pincushion distortion in the corners.

Autofocus Operation
Autofocus is conducted electronically by UDS (Ultrasonic Silent Drive), and it takes less than one second to focus from infinity to closest focus -- it's very quiet as well. The front element doesn't rotate during focus operations, but since filters can't be attached to this lens that's of little significance. Autofocus results can be overridden at any time by just turning the manual focusing ring.

Macro
You don't generally buy an ultra-wide angle lens for macro performance, and in this case you won't see amazing performance - just 0.2x magnification, but it does benefit from a minimum close-focusing distance of 11 inches.

Build Quality and Handling
Tamron's new lens design format uses a very modern type face, and a stippled black matte finish. The lens mount is metal; the filter ring is plastic, and there are weather seals integrated into the lens design. The lens offers a windowed distance scale, marked in feet and meters. The lens features full-time manual focus override: that is to say, you can autofocus and turn the focusing ring to adjust focus manually at any time. There are two switches on this lens: one to enable/disable autofocus, and the other to enable/disable the Vibration Control (VC) system. The lens aperture is designed with nine curved diaphragm blades.

Tamron has elected to swap the position of the zoom and focus rings: where most other manufacturer's zoom rings come first, and the focus ring further away from the body, it's the opposite for this Tamron. Also, if it matters to you, the manual focus ring direction echoes Nikon lenses, rather than Canon. The focusing ring is about 5/8" wide and is rubber-coated, with deep rubber ribs. Since the lens now uses an electrical focusing system there are no hard stops on either end of the focus throw and the ring will turn forever in either direction.

The zoom ring is about 1 1/8" wide with a ribbed, rubber coating. The ring has a relatively short throw - it takes about 50 degrees to turn through the entire zoom range. The lens doesn't use an internal focus system, so there is lens extension as the lens zooms out to 15mm, but it's covered by the built-in lens hood so there's little risk of damage.

The lens features Tamron's Vibration Control (VC) image stabilization system, but in this lens it's not especially useful for stills. At the wide end it provides about a half stop improvement, and at 30mm it provides perhaps a stop of improvement. I do think it will be very useful for movie-making, helping to smooth out camera movement. It's worth looking at our IS Test tab for greater detail.

As we've mentioned, the lens hood is built-in, and there are no filter threads on the front of the lens, nor is there capacity to drop in or attach filters to the rear of the lens. If you want to use a polarizer with this lens, or any filter for that matter, you'll need to invest in a third-party system.

Alternatives

Canon EF 16-35mm ƒ/2.8L II USM ~$1,500
The Canon is a bit sharper, but corner shading is a bit more significant on a full-frame body. It has the fast ƒ/2.8 aperture, but no image stabilization. It's also more expensive, but you are getting Canon's premiere L-glass.

Nikon 16-35mm ƒ/4G ED VR II AF-S ~$1,100
The Nikon and Tamron produce similar results for performance, though the Nikon has a bit better results for corner shading on full-frame. The Nikon also offers image stabilization, but only stops down to ƒ/4. They're comparably priced.

Sony 16-35mm ƒ/2.8 ZA SSM II Zeiss ~$2,250
Sony products always have a bit of a premium price attached, and that's no exception for this product. We haven't yet tested this lens, but it offers the same ƒ/2.8 aperture, however, no image stabilization.

Sigma 12-24mm ƒ/4.5-5.6 EX DG Aspherical HSM ~$1,000
You can't actually buy this version of the Sigma 12-24mm, and we haven't yet reviewed the new version II of this lens. This was the grand-daddy of ultra-wide lenses, offering a staggering 12mm wide angle on a full frame body. It doesn't offer image stabilization, and it is far from the fast ƒ/2.8 aperture offered by the Tamron, but for a similar price you get much wider performance. Optically, it's much worse, but if you stop it down it's fairly good.

Conclusion
Tamron's produced a compelling lens for those who are interested in ultra-wide angle photography, and it's priced competitively. However, there are a couple of notes to consider here. The first is the much-touted ƒ/2.8 aperture. That might be important if you're shooting indoors - the extra stop is fairly useful - but it does come with a trade-off for image quality, at least when used on the full-frame Canon 1Ds mkIII. Shooting outside, there's little incentive to use it, as you won't really get blurred-out backgrounds unless you frame your shots so you are very close to your subject, and even then, you might not notice.

The other selling feature of the lens is the Vibration Control system, which is nice to have, but with the results we have obtained, it won't be a substitute for a tripod. VC will be nice to have for movie-making, but for general use, you'll do fine without it.

Product Photos

Sample Photos

The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.

Still Life shot

VFA target

As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.