Tamron's newest lens; SP 150-600mmReviewed by freelance photographer/writer Peter K. Burian. |
Article & Images by Peter K Burian |
Professional sports and wildlife photographers often use a 500mm or 600mm f/4 lens, but this type of gear is massive, heavy and expensive, selling for more than a good used car. That's why the Tamron SP 200-500mm f/5-6.3 Di zoom was such a popular alternative among photo enthusiasts. Since it was first released however, new technology has been developed, so its successor boasts some significant benefits. The new 150-600mm zoom offers greater versatility in focal lengths plus fast/silent Ultrasonic Silent Drive autofocus and the Vibration Compensation image stabilizer. |
Lens Construction |
There's a zoom lock (at 150mm) to prevent the internal barrel from extending while you're carrying the lens pointing downward. Other amenities include a VC (stabilizer) On/Off switch, a distance scale under glass, an AF/MF switch, and a focus limiting feature (49 feet to infinity). The latter allows for faster focus acquisition in situations where your subjects are always far from the camera. Thanks to internal focusing the front element never rotates. The high-torque USD motor allows for manual focus override in AF mode, useful when you want to slightly tweak the point of focus. |
The lens designers specified three large LD (Low Dispersion) elements to correct chromatic aberrations which would otherwise cause image softness or color fringes around subject edges. A deep lens hood minimizes the risk of flare, but Tamron also employs eBAND and BBAR (Broad-Band Anti-Reflection) multi-layer coatings to control ghosting in strong side lighting. |
With the EOS 6 that I used, autofocus was virtually silent and lightning fast, especially in the 150mm to 400mm range. Focus tracking of alpine skiers approaching the camera was very good, with a series of ten frames all sharply rendered. At longer focal lengths, the maximum aperture is a smaller f/6.3, allowing less light to reach the camera's AF sensor. That occasionally led to missing some initial shots until focus was acquired, but this is a fact of life with any lens featuring a small maximum aperture. (A wider aperture would have dramatically increased the size/weight/price.) For the most reliable autofocus in the 400mm to 600mm range, I recommend using the camera's central focus detection point instead of multi-point AF. |
Performance Evaluation |
At longer focal lengths, images made at f/6.3 exhibit high central sharpness, but with a full-frame DSLR like the EOS 6D slightly soft corners. (Of course, the edges of an image are cropped when using a DSLR with the more typical sensor size for even better overall quality.) In any event, the most important subject elements are rarely very far off-centre in sports and wildlife photography. For maximum resolution of an owl and its surroundings at long focal lengths, I stopped down to f/9.1. This also provided greater depth of field to keep the environment in focus. Thanks to the nine blades in the diaphragm mechanism, defocused highlights in the distance are circular instead of octagonal for a pleasing bokeh. |
Tamron's proprietary Vibration Compensation image stabilizer is certainly effective. (It's not included in the Sony mount lens because Alpha cameras have their own stabilizers.) Without the VC system, I generally needed to work at around 1/640sec. for razor sharp images of static birds at 600mm when hand-holding the lens. After activating the stabilizer, I was often able to get comparable results at 1/90 sec. |
Final Assessment |
See more of Burian's work and bio at www.peterkburian.com |