Photo packs have come a long way in the past decade, especially those that are targeted toward outdoor and adventure photographers. Alaska-based adventure photographer Dan Bailey takes a closer look...
The Tamron SP 70-200MM F/2.8 DI VC USD, (compare prices) (review) is a new lens from Tamron. There is also a 70-200/2.8 USD lens (without stabilization), but the new lens isn’t just the old lens with VC added. It’s a new design with additional elements including 1 XLD (Extra Low Dispersion) glass and 4 LD (Low Dispersion) elements. The new lens also has USD (ultrasonic drive) with full time manual focusing, Tamron’s VC (vibration control) which provides around 4 stops of additional stability and is weathersealed against dust and moisture.
The only areas in which the older lens has advantages are in price (the new VC lens is about 2x the price of the old lens) and magnification. The older non-VC lens has a maximum magnification of around 1:3.1 (about 1/3 life size), while the new lens has a maximujm magnification of 1:8 (about 1/8 life size).
The Tamron 70-200/2.8 VC USD is (or soon will be) available in Canon EOS, Nikon and Sony compatible mounts. The lens reviewed here had a Canon mount. Since Sony DSLRs use a sensor shift mechanism for stabilization, the Sony version of the lens is not optically stabilized. Currently (01/13) the Canon version is already in the stores at a price of around $1499. The Nikon version should be available soon at the same price, followed by the Sony version.
The Tamron 70-200/2.8 VC USD feels like a solidly built lens. The focus and zoom controls are smooth and well damped. Composition appears to be a mixture of metal and plastic. I haven’t taken it apart, but my guess is that the lens has a metal barrel with plastic covers and zoom rings. There is a removable metal tripod mount and the lens is supplied with a “petal” style hood. The rotating tripod mount is a “friction” type, i.e. there are no clickstops and rotation is clamped by tightening up a knob next to the tripod foot.
The weight of the lens, 51.9oz, is typical for a lens in this class. For comparison, the Canon EF 70-200mm f/2.8L IS II USM weights 52.6oz. It’s not light, but it can easily be handheld and balances well on the camera (I used it on an EOS 7D and an EOS 5D).
The Tamron 70-200/2.8 VC USD has two mode switches. One turns the AF system on and off, though manual focus is available at all times even in AF mode. The other switch turns the stabilization system (VC = vibration control) on and off.
The is no range limiting switch. Range limiting (e.g. allowing focus only from 5m to infinity) can speed up AF acquisition is the subject is within that range and the AF system has to search for focus. There is also no switch to allow control over which axes the VC system operates on. Some lenses have a switch which makes the stabilization system respond only to movement along one axis (usually vertical to facilitate horizontal panning).
The only reason to turn of the VC is when the lens is mounted on a tripod and shutter speeds are long. Under such condition optical stabilization can drift. This applies to all optical stabilization systems from all lens manufacturers.
In practice the lack of range limiting and VC axis control did not cause any problems, though it’s possible that under some circumstances either function could be useful.
The Tamron 70-200/2.8 VC USD has a distance scale marked in both ft and meters. Infinity is on the left side of the scale and closest focus (4.3 ft) is on the right side of the scale. This means that the direction of rotation of the focus ring is opposite to that of Canon EF/EF-S lenses. Again, in actual operation this didn’t present any problems, but it’s something to be aware of.
The zoom ring is marked at 200mm, 135mm, 100mm and 70mm, with 200mm on the left and 70mm on the right. Again this is opposite to direction in which Canon EF/EF-S lenses zoom. Not a problem but something to be aware of.
Note that Nikon users will regard the focus and zoom rotation directions as “normal” since both are opposite to those used by Canon!
Focus was fast and accurate. Tamron’s USD (UltraSonic Drive) is comparable to Canon’s USM (UltraSonic Motor) in that it allows full time manual focus and is essentially silent in operation. I measured a time of 0.3 seconds from infinity to close focus (or close focus to infinity) under bright conditions with the lens on an EOS 5D.
All comments on resolution are based on an analysis of images of both test charts and real world subjects. Images were taken using and EOS 5D for full frame corner analysis and an EOS 7D for center and APS-C corner analysis.I looked at two samples of this lens. Unless otherwise stated, their performance was similar.
Wide open at 200mm the Tamron 70-200/2.8 VC USD has pretty good resolution in the center of the image, but one sample was a little low in contrast when wide open and didn’t reach full contrast until f4. The second sample was better, with a touch of lowered contrast wide open and pretty much full contrast closed down by just 1/3 stop. This effect wasn’t as noticeable in “real world” images as it was when shooting resolution test charts. Using the EOS 7D I measured an effective horizontal/vertical limiting resolution of about 88 lp/mm, equivalent to about 2600 LPH. This is more a sensor limitation than a limitation due to the lens resolution, though it does indicate that the lens is sharp.
Based on shots of resolution test targets (mirror lockup, cable release), both lenses gave the sharpest images with the EOS 7D microfocus adjustment set to -10 units, though the images with no microfocus adjustment were almost as sharp. As a reference, my Canon 85/1.8 gives the best results with no microfocus adjustment.
Stopping down from f2.8 to f4 and f5.6 doesn’t affect center sharpness very much, though on resolution chart tests there is a fractional improvement in resolution at f4 and again at f5.6. The corners do sharpen up a little more though. At f8 corner sharpness is maximized, but center sharpness shows a touch of softening due to diffraction effects.
At 135mm wide open at f2.8 center sharpness is high, with the full frame corners a little softer. Stopping down to f4 and f5.6 again results in a marginal sharpness increase in the center but the corners do sharpen up slightly. Again at f8 you can see slight diffraction softening in the center, but corner sharpness peaks and pretty much equals center sharpness.
At 70mm the same story repeats. Very good center sharpness wide open at f2.8, with a very slight improvement at f4 and f5.6 and slight diffraction softening at f8. Corner sharpness peaks at around f8.
Overall I’d have no hesitation shooting with the Tamron 70-200/2.8 VC USD wide open when I needed the speed, though I’d close down 1/3 stop if I wanted to maximize contrast. Overall image quality is very good. If I wanted absolute maximum sharpness in the center, I’d shoot between f4 and f5.6, though on many real world subjects there would be little visible improvement over wider apertures, especially if care was not taken to maximize camera stability (e.g. using a tripod). If I was full frame shooting landscapes that required corner to corner sharpness, I’d probably stop down to f8 to optimize the corner image quality, though I’d normally stop down to at least f8 anyway for landscapes to increase my DOF. At apertures smaller than f8 diffraction begins to soften the image as it does with all lenses on 35mm format cameras.
The Tamron 70-200/2.8 VC USD shows some vignetting at wider apertures when shooting full frame. Measuring at about 90% of the distance from the center to the corner of the (full) frame with focus around infinity, both at 200mm and 70mm I estimated approximately 1.3 stops at f2.8, 2/3 stop at f4, 1/2 stop at f5.6 and less than 1/3 stop at f8. The image on the right shows the vignetting wide open at 70mm. On most “normal” images this represents fairly mild vignetting, but if you are shooting uniform tone subjects (e.g. the sky) you may notice some corner darkening, especially if shooting wide open at f2.8. For comparison, the Canon EF 70-200/2.8L IS USM shows pretty similar numbers.
The degree of vignetting was pretty equal at all four corners of the frame throughout the focal length range, as it should be for a well aligned lens.
Looking at an APS-C frame, vignetting in the corners was considerably less evident, with less than 1 stop at 200mm and less than 1/2 stop at 70mm wide open, dropping to under 1/3 of a stop by f4.
Chromatic aberration is well controlled. It is visible towards the corners of the full frame image at 200mm and 70mm as slight green/red fringing, but pretty much absent at 135mm. At 200mm the fringing is red on the outside and green on the inside of dark lines against a white background, while at 70mm the order of the colors is reversed. CA would only be likely to be an issue in high contrast features (e.g. dark lines against a light sky) near the edges and corners of the frame. Even then you’d need to be making large prints to see the CA. The examples on the right are 300% crops from the corners of full frame images, i.e. the image enlarged 3x larger than a 100% crop. At 100% crop size, the CA is hard to see.
Tamron include a licence for a limited edition of “SilkyPix”, a RAW converter which has aberration corrections for the Tamron 70-200/2.8 VC USD built into it. The corrections are for vignetting, distortion and chromatic aberration and they are quite effective at minimizing or eliminating these aberrations. The only problem is that the limited edition of Silkypix is…well…limited. The available (and unavailable) functions are listed at http://www.tamron.com/en/download/silkypix/
Users of Canon’s DPPRAW converter won’t be surprised to learn that aberration correction is not available. Normally only Canon lenses are supported by DPP’s aberration correction functions.
Distortion was very well controlled. At 70mm it measured around -0.7% (barrel),. At 135mm very slight pincushion distortion was noted at about 0.7%. with a slight increase at 200mm to around 1% (SIMA). These are pretty low numbers for a lens of this type and unlikely to be noticed in typical images, though on shots with straight lines at the edges of the frame (e.g. architecture) some distortion may be noticed. Fortunately, distortion is fairly easily digitally corrected if it is an issue.
No problems were noted with flare. With the sun actually in the frame some flare was evident (as it would likely be with all lenses), but in normal use flare wasn’t an issue. The lens is supplied with a “petal” style bayonet fitting hood which will certainly minimize any flare issues when shooting close to the sun.
Bokeh is hard to quantify, but the out of focus backgrounds in shots taken with the Tamron 70-200/2.8 VC USD generally were pleasingly smooth. The images on the right compare shots taken at 200m with the lens at f2.8 and f5.6.
The performance of the optical stabilization (VC) was quite impressive. Once the VC system engages fully (which does require a fraction of a second), I could fairly reliably get sharp images at 200mm using a shutter speed of 1/20s. Not every shot would be as sharp as one taken at 1/200s on a tripod of course but a good fraction were close. Using the standard of “1/focal length” as the reference speed, 1/20s represents 3.3 stops of stabilization (1/25s would be 3 stops).
Even at 1/10s at 200mm (4.3 stops of stabilization) most of the images were quite usable, though viewed at 100% weren’t quite as sharp as shots at higher speed.
With a lens as long as 200mm, I’d say that some form of image stabilization is essential for hand held work unless you’re always out in bright sunshine or are prepared to always shoot wide open and/or at high ISO settings. Personally, I would not buy an unstabilized 70-200mm lens for handheld use, and the Tamron stabilization system seems to be as effective as any on the market today.
The Tamron 70-200/2.8 VC USD exhibits what is sometimes referred to as “focal length breathing” or sometimes “focus breathing”. That means that the effective focal length (or angle of view, or magnification) changes with focus distance, specifically the closer the focus the shorter the focal length at any given zoom setting. This is somewhat difficult to measure, but at the a close focus distance of 2m I’d estimate that the “true” or “effective” focal length with the zoom set to 200mm is closer to 140mm. A lot of zoom lenses do this to a greater or lesser extent. At infinity I measured a focal length of 196mm, which is pretty typical for lenses which are nominally “200mm”, while at 10m I measured a focal length of 188mm. The Nikon AF-S 70-200mm F/2.8G ED VR II is known to exhibit a similar (if not even larger) focal length change as a function of focus distance.
There’s no doubt that the Tamron SP 70-200MM F/2.8 DI VC USD, (compare prices) (review) is a good lens. It’s sharp, even wide open, aberrations are well controlled and the optical stabilization (VC) is very effective. So the only question is whether it’s good value at $1500.
Well, if we look at the Nikon 70-200mm f/2.8G ED VR II AF-S, (compare prices), it’s selling for $2400 and if we look at the Canon EF 70-200 f/2.8L IS II USM, (compare prices) its retail price is $2500 (though the street price is closer to $2200 right now). So the Tamron lens is around $700 cheaper than the Canon and$900 cheaper than the Nikon equivalent. The previous version of the Canon lens sold for around $1650, but has now been discontinued. The Sony 70-200mm f/2.8 G retails for around $2000, so the Tamron lens would still be $500 less expensive, even if the non-stabilized Sony version sold for $1500 (Sony have stabilization built into the camera body). The Sigma 70-200 f/2.8 APO EX DG HSM OS for Canon, (compare prices) can currently (02/13) be found for around $1250.
Though I didn’t get the opportunity to shoot the Tamron 70-200/2.8 OS HSM side by side with the Canon EF70-200/2.8L IS II USM, I have looked at both lenses. The Canon has a few more features (two IS modes and 2 focus ranges), comes with a zippered carrying case, is optically excellent and has a very effective IS system. Comparing the two lenses optically, I’d say that the Tamron comes very close to the Canon lens.
Taken overall, the level of performance of the new Tamron 70-200/2.8 VC USD, along with the 6 year warranty (Canon have a 1 year warranty, Nikon have 1 year international plus 4 years USA, Sigma have 1 year world wide + 3 years USA) justifies the $1500 price tag and, in my opinion, represents more “bang for the buck” than either the Canon or Nikon current lenses. If the prices on the Canon and Tamron lenses were the same, I might pick the Canon, but given the price and warranty difference and the similarity of the optics, I’d probably go with the Tamron if I was spending my own money!
Tamron SP 70-200MM F/2.8 DI VC USD, (compare prices) (review). From the Tamron catalog: A wide-aperture telephoto lens packed into a body that’s smallest in its class, with further advances in image quality and performance. This is a wide-aperture telephoto zoom lens compatible with full-size SLR cameras….