How good is Tamron’s first lens for Sony NEX cameras? This attractive, well made, nicely finished long-range zoom in Tamron’s first lens offered in the Sony E-mount for APS-C-format Sony NEX compact interchangeable-lens compact cameras. It provides an equivalent focal-length range of 27-300mm and it’s designed for mirrorless NEX cameras only-it will not work on Translucent Mirror Technology Sony Alpha DSLRs, even though they use the same size sensor, due to differences in optical design and back focus.
The Tamron 18-200mm Di III VC is available in silver or black finish that visually complements any NEX model. More important this compact (4-inch long at 18mm, 2.7-inch-wide) lightweight (16.2 ounce) lens balances very well on any of the current or previous NEX cameras, forming a seamlessly integrated, functional unit. The barrel extends to 6-3/4 inches at the maximum (200m) telephoto position, but it doesn’t feel front heavy and still balanced very well on our Sony NEX 7 test body. The 1-1/4-inch-wide textured rubberized zoom ring is conveniently positioned toward the front of the barrel, is easy to grasp, turns with commendable smoothness, and has a well-damped action. The finer-textured ½-inch-wide manual focus ring operates with equal finesse and precision. It’s placed about 3/4 an inch forward of the lens mount, allowing for easy manipulation on all NEX models when top-mounted accessories are used. There’s also a sliding-tab lock that lets you lock the barrel at the 18mm zoom setting when not in use, but zoom creep is not a problem with this lens.
Focal Length 18 – 200 mm for APS-C format
35mm equivalent focal length: 27-300 mm
Aperture Maximum: f/3.5 – 6.3
Minimum: f/22 – 40
Camera Mount Type Sony (E Mount for NEX) Format Compatibility DSLR (APS-C Sensor) Angle of View 76 deg – 8 deg Minimum Focus Distance 1.64 feet (0.5 m) Maximum Reproduction Ratio 1:3.7 Groups/Elements 13/17 Diaphragm Blades 7 Features: Image Stabilization Yes Autofocus Yes Tripod Collar No
Shooting with a Sony NEX using a wide-to-long-telephoto having an 11.1X zoom ratio reveals the inherent potential of these cameras, and there are other practical advantages besides focal-length flexibility. It focuses down to 1.5 feet (45cm) over the entire zoom range using a “new mechanical configuration,” providing a maximum macro magnification ratio of 1:3.7-great for frame-filling head shots. It’s 7-bladed diaphragm provides a nearly circular aperture for better bokeh (smooth transitions in out-of-focus areas of the image), and its built-in VC image stabilization system provides up to a 4-stop advantage in minimizing blur due to handheld camera shake-especially important when shooting at long focal lengths or in dim lighting conditions. The VC system operates so smoothly you seldom notice, but you must make sure to enable image stabilization via the camera body. Sony calls it SteadyShot and it’s in the Setup menu. It also helps to partially depress the shutter button and wait an instant (around half a second) for the system to activate before taking the shot.
Generally I was favorably impressed with the overall field performance of the Tamron 18-200mm Di III VC. It focuses with very consistent accuracy on the NEX 7, which uses contrast detection AF, and it delivers outstanding image quality over the entire focal length range, with excellent sharpness and crisp detail at all apertures, even wide open. At its optimum aperture of f/8-f11 (depending o0n focal length) its performance is superb, and there is no observable loss of sharpness at the 200mm maximum telephoto setting, a common deficiency in long-range zooms. The VC (Vibration Compensation) system was also very effective, allowing us to take sharp handheld pictures in the mid-telephoto range at 1/13 sec and even slower. The moderate maximum aperture of f/6.3 at the 200mm setting does impose limitations in low-light shooting without using flash or a tripod, but with the excellent performance of NEX cameras at high ISO settings in the 1600-3200 range, this seldom proves problematic, especially in daylight shooting.
I shot field test images with this lens using a 24.3 MP Sony NEX 7, deliberately selecting a wide variety of focal lengths, apertures, and shooting distances to put it through its paces. The subjects included informal portraits and street scenes, architectural details, finely detailed close-ups, and a well-constructed brick wall to ascertain linear distortion. Most of my test images were shot handheld, but I used a tripod when field-testing linear distortion and chromatic aberration.
As mentioned this lens delivers above-average performance for a long-range, wide-angle-to-telephoto zoom, and I found this to be true at all focal lengths from 180-200mm. Sharpness in the center of the field was uniformly very good at maximum aperture, which ranges from f/3.5-f/6.3, but there was a slight increase in crispness (detail plus contrast) when I stopped down 1-2 stops from maximum aperture. Off axis, I noted a slight drop-off in sharpness at the edges of the image field, particularly in the 135-200mm range, but again stopping down enabled me to achieve more uniform sharpness across the field. Based on my extensive experience with other 27-300mm-equiavlent zoom lenses, I judge this lens to be among the top tier performers in its category.
To check for the presence of chromatic aberration I photographed a detailed linear subject with sharp white edges, illuminated by brilliant sunshine-a very severe test. I was able to detect slight purplish color fringing at the edges of the image field only in images shot at the 200mm (300mm equivalent) setting, and this was visible at all apertures. Under similar test conditions there was no detectable color fringing at the 18,mm-135mm settings-an outstanding performance. I conclude that the level of chromatic aberration, even at the 200mm setting, is well within acceptable limits, even for critical subjects such as architectural photography.
Images shot into the sun, with the sun placed just outside one corner of the frame exhibited slight loss of contrast, especially at the 18mm and 35mm settings, and a very slight loss of contrast at the telephoto end. Overall, the level of flare suppression provided by this optical design and efficient multi-coatings is commendable, and shooting in high-flare situations should not prove problematic except in extreme cases, where using the supplied sunshade to keep the sun directly off the front of the lens may help in some circumstances.
I shot a series of images of a well constructed brick wall with the camera’s image sensor parallel to the brick surface at all marked focal lengths-18mm, 35mm, 50mm 70mm, 100mm 135mm and 200mm. There was no observable linear distortion except at the widest-angle (18mm) setting where there was moderate barrel distortion visible as outwardly bowed lines that were increasingly evident toward the edges of the image field. This is pretty much par for the course for a long-range zoom. I do not judge the amount of barrel distortion to be excessive, but at 35mm it is not ideal for critical subjects such as architectural photography. I did not conduct a specific test for light falloff, but in examining a wide variety of test images I judge it to be minimal at all focal length settings except at 18mm and 35mm, where it is moderate. This is a very good performance for a lens of this type.
This is a first class long-range zoom lens that is sure to delight discriminating Sony NEX enthusiasts. The only real downsides are its limited f/6.3 aperture at the longest focal length, and a typical amount of linear distortion and light falloff at the widest-angle settings. I was especially pleased with its performance at the longest focal-length settings and at near-macro distances. It is also worth noting that this is a very handsome lens indeed. Judging by the enthusiastic comments we received from knowledgeable shooters we encountered in our travels, it may make your fashionably slim Sony NEX look even cooler. At a street price of $739 this is not a lens for the penny-pinching or the faint of wallet, but based on my findings I confident that if you take the plunge you’ll get what you paid for.