This fast standard zoom lens from Tamron is their entry into the superior performance, standard zoom built for cropped sensor category. With an aperture that opens to f/2.8 and an image circle that is suitable only for APS-C ‘cropped’ sensors, we take a look at how it performs.
- Focal Length 17-50mm
- Max aperture f/2.8
- Min aperture f/32
- Construction 16/13 elements/groups
- Min focus 0.27m
- Filter size 67mm
- Size 74x81.7mm
- Weight 0.434kg
- Mount Available Canon, Nikon, Sony
- Price (SRP) £349.99
Build and handling
This lens is well built and specified for its ilk although it lacks the silent smoothness of autofocus by sonic motor. The bulk of the main barrel is taken up with the zoom ring, which is quite nicely torqued in its operation. The travel from the 17mm mark to the 50mm one is almost exactly a quarter of a turn and that extends the front element by some 30mm, although it does not rotate the front element. A zoom lock is provided to stop this extension during transport, although it was not needed with the lens being new. Forward of the zoom ring is a manual focus ring that has a distance guide marked on it. The (IF) in the long-winded title means internal focus, overcoming any physical change in the lens during the focussing operation.
The AF mechanism is a little whiny, although not obtrusively so, and accurate although it takes a couple of small jerks to get there in low light. The finish is a good standard and not as plasticy as some of Tamron’s older offerings.
With modern lenses, standards are rising all the time and this lens has managed to keep up. The resolution is quite good, especially when closed down by a stop and it is fairly consistent across the frame and, surprisingly, throughout the zoom range with neither one end or the other being noticeably better than the other.
The control of CA is exceptionally good with even Imatest struggling to find any at most apertures and focal lengths. There were measurably incidences at the widest apertures, but they were well below the threshold where they might become visible to the eye.
The only place where the lens lets itself down is in the control of distortion. At the longer 50mm end it is within the parameters of acceptability with a pincushion reading of 0.62% but at the wide end of 17mm it has jumped to a rather noticeable 4.39% barrel which is very noticeable. Fortunately it is one of the easier problems to solve in software.
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Below is our lens test data. To find out how to use these graphs look at this article: How we test lenses
With the exception of the distortion at the wide end, this is a very competent lens and a considerable jump up from the general standard of kit lens that it would replace. There is little else that lets it down and good resolution across the frame that is acceptable even when the lens is used wide open commend it. The only other place it could be improved is in the autofocus system where Tamron really do need to get a sonic motor.
In summary, the positive points of the SP AF 17-50mm f/2.8 XR Di11 are:
Good resolution and control of CA
Nice build, an improvement for Tamron
Consistent through the focal range
The negative points are:
Distortion at the wide end.
No supplied case or pouch.
Check the latest price for the Tamron 17-50mm f/2.8 Di11 here
Discuss this lens and other related lens subjects here
Test by Ian Andrews www.wildaboutkent.com