Besides a new appearance to match that of the more recent SP models, and improved weather sealing, the lens has what Tamron calls a “Flex Zoom Lock,” or sliding zoom collar to allow the barrel to be locked in place at any zoom setting, as well as a more conventional locking button at the minimum focal length.
The front element gains a fluorine coating to aid cleaning, and internal improvements include a refreshed optical construction with 21 elements in total (in 13 groups), three of which are low-dispersion types to reduce chromatic aberration. Sports and nature photographers will also appreciate the new minimum object distance, reduced from 2.7m (106.3 in) in the old model to 2.2 (86.6 in) in the G2.
Along with the introduction of two matched teleconverters, the lens is also compatible with the company’s optional TAP-in Console. Attached via the lens mount, the console provides USB connection to a computer and allows the user to update the lens’s firmware as well as to customize the focus adjustment, the focus distance limiter, the stabilization, and the manual focus settings without having to return the lens to Tamron.
With a 95mm accessory thread, and measuring 10.24 x 4.27 in (260.2 x 108.4mm), the reviewed Canon-mount model is highly compact (at 150mm, at least), and weighs a not-unreasonable 70.9 oz (2.01kg).
Measurements: Good sharpness level
When tested on the highest-resolution body in Canon’s lineup — the EOS 5DS R body with full-frame 50-Mpix CMOS sensor and anti-aliasing cancelling OLPF — the new SP150-600mm F5-6.3 G2 model has good sharpness levels, particularly at the shorter end of the zoom range.
From around 300mm (where it’s most prized), however, sharpness falls quite rapidly, but this is fairly typical in telephoto-zoom lenses like this. Otherwise the G2 has low distortion and vignetting, and control of lateral chromatic aberration (measuring just 8 microns at its highest) is excellent.
Tamron SP 150-600mm f/5-6.3 Di VC USD G2 (Model A022) Canon vs. Tamron SP 150-600mm F/5-6.3 Di VC USD (Model A011) Canon: Slight difference at longer focal lengths
Despite the upgrade to the optical construction, which includes an additional element over its predecessor, the new lens’s overall image quality has dropped very slightly. Transmission is a little lower and distortion is up slightly; neither of those things are going to worry anyone, but vignetting has increased (albeit in the extreme corners), and overall sharpness levels have dropped, particularly at the edges.
Whether any of this would be enough to see in the field is probably unlikely, but where the earlier model was pretty impressive wide-open at all focal lengths, including 600mm, this new G2 model is slightly less so. The new model is very sharp at the wider end, just as with the earlier model, but sharpness drops as you zoom through the range to 600mm, where it’s most noticeable.
Tamron SP 150-600mm f/5-6.3 Di VC USD G2 (Model A022) Canon vs. Sigma 150-500mm F5-6.3 APO DG OS HSM Canon vs. Canon EF 100-400mm f/4.5-5.6L IS II USM: Good overall performer optically
Tamron isn’t the only maker with a 150-600mm zoom in its lineup: rival Sigma has not one, but two models: the 20-element Contemporary and the 24-element Sports. While they’ve yet to be put through their paces in our Paris-based lab, the earlier Sigma 150-500mm F5-6.3 APO DG OS HSM — a stabilized model with a sonic-type AF motor— is very close in performance. It is similar in peak sharpness, though it’s more consistently sharp across the field at most apertures and focal lengths.
While Canon has some impressive super-telephoto primes and a splendid EF 200-400mm F4L IS USM Extender 1.4x (with a built-in teleconverter), they’re neither cheap nor compact and lightweight. The closest lens in the lineup is currently the Canon EF100-400 F4.5-5.6L IS II USM, and even then, at around $2000, it’s the priciest of the three.
Still, you tend to get what you pay for, and although the Canon doesn’t have the reach, it has the highest peak sharpness levels as well as the most consistent sharpness across the frame among the bunch. Even at 400mm, where it is at its weakest, it still comfortably outperforms both the Tamron and the Sigma at the same focal length. And let’s not overlook the fact that on an APS-C camera such as the EOS 7D Mk II, the Canon would offer a similar angle of view.
Tamron has done much more than just a casual update of this lens, having totally redesigned the exterior, added improved weather sealing and a new quick-locking mechanism to maintain a set focal length, and even included a built-in Arca-Swiss compatible lens plate in the foot of the removable tripod collar.
Tamron has also refreshed the optical construction by adding an extra element to the rear. While this has resulted in a very slight drop in sharpness with respect to its predecessor (mostly in the outer zones), it’s still a great performer optically and it remains a hugely attractive option at a highly competitive price.