Lens Review – Tamron SP 24-70mm F/2.8 Di VC USD
Introduction.
The Tamron 24-70 f2.8 is the first lens in this zoom range to have Vibration Control. It comes with several high quality glass elements to deliver sharp, problem free images. The lens has variable length and has a wide open aperture of 2.8 throughout the zoom range. The other important feature is an ultrasonic drive for silent, fast and accurate autofocus. The lens comes with full-time manual focus.
Build
The Tamron 24-70 f2.8 VC feels sturdy with just the right amount of weight (825gm). Mounted on a 5D MarkII, the shape and weight are an ideal composition for getting shake-free images at low shutter speeds. The surface of the lens feels a little plasticky, but is not much of a concern. The zoom ring is slightly harder to operate, which sometimes doesn’t allow you to quickly get ready to compose a shot.
The things that I would really like to see change in the build for Canon mounts is the direction of the rotating elements. The zoom ring and manual focus ring operate as left hand screws, which can be confusing and take time to get used to. Similarly, a zoon ring located towards the camera rather than towards the filter side of the lens would have made the handling easier and seamless.
The filter dia is 82mm. It would have been more convenient if Tamron designers could come up with 77mm threads, which would have made it easy to use one set of filters interchangeable with many lenses.
Performance
Autofocus is silent, accurate and fast it takes barely noticeable time to lock into the subject. I could not find any reasons to complain, although I did not test it in low-light or extreme conditions. In normal conditions, you can trust on the AF system to give you instant and accurate results.
The vibration compensation would definitely help in pushing the limits of shutter speeds, however, I would have preferred to see Tamron provide a lower cost option without VC. Many photographers can handle shutter speeds of the order of 1/30sec or lower at these focal lengths without the aid of VC, though an equal number of people may benefit from having VC. By providing a choice between the two, Tamron can appease both kind of photographers.
Image Quality
The Tamron 24-70 f2.8 VC scores very high in terms of image quality. There is no room to complain when it comes to sharpness of this lens. Images have no visible softness on both ends of focal length.
Probably because of its low-dispersion and extra refractive elements, there is surprisingly little Chromatic Aberration. Even in some high-contrast situations where you come to expect a lot of CA, the lens handles very well and beats the expectations.
Vignetting was also very little and was barely found even in situations where I was expecting to see under-exposed corners.
There is an evident barrel distortion at 24mm which can spoil the vertical lines at the edges in architectural photography. An automatic correction using lens profile in Lightroom reduced the problem considerably. A slight manual override after automatic correction got me acceptable results.
Below are some sample images I created. You can click on them to download full size image. Full size images have exif data embedded.
Conclusion
Tamron 24-70 f2.8 VC delivers good sharpness and image quality. While I would like to see a few changes in its construction, especially for Canon mount, this is something that a user may get used after some time. For the price at which it retails, this lens is an excellent value for money. However, I would also like to see a non-VC option which can drive the price further down.
Lens image courtesy of Tamron.