The Tamron 24-70 f/2.8 Di VC USD is, at first glance, something that many full frame shooters have been wanting for quite a while - the versatile 24-70mm focal length range, the f/2.8 aperture and most importantly the addition of image stabilisation.  Canon released their Mark II 24-70mm in 2012 and surprised everyone by omitting IS, albeit with improvements to the already-excellent optical quality to stunning new levels. 

This has left the door open for other lens manufacturers to provide an offering to those shooters who are prepared to exchange a little image quality for the benefits stabilisation brings - after all, lens shake will ruin photos regardless of how sharp your lens is.  The Tamron 24-70 is the world's first stabilised large aperture zoom in this range.

I've had the Tamron 24-70 for a little over 6 months now and had plenty of time to see the best this lens has to offer as well as pick up on any flaws or niggling gripes that might take weeks & months to appear.  Testing was performed using Canon 6D & 550D bodies.

Out of the Box

As well as the lens, Tamron supply a centre-pinch lens cap & lens hood.  No bag or case is included.

Handling & Build Quality

Like other recent Tamron lenses the build quality and feel of the 24-70 is spot on.  It feels balanced in the hand and although an f/2.8 zoom is always going be relatively heavy, weighing in at 825g, when attached to the camera the centre of mass is well-placed and comfortable to hold.  Build quality is reassuringly sturdy and the lens is made from a combination of engineering-grade plastic and metal. It certainly feels on a par with it's Canon L-grade competitors.  Although, peculiarly, the Tamron site makes no specific mention of weather sealing, the lens is one of the first Tamron lenses to feature this - using it out in the rain (with a suitable camera body) was no issue at all.

Over the last 6 months I've taken this camera away on a range of trips, including to some fairly out of the way places, and the lens has held up to all the abuse I've thrown at it!  From changing lenses in the rain or on dusty trails, the only sign of wear and tear so far is that some of the black lettering on the gold ring is wearing off.  Then again, this is pretty common for every lens I've owned across any manufacturer.

For the vast majority of day-to-day use and holidays/vacation, this lens is sturdy enough to take a bit of a beating and from a build & construction point of view will not let you down.  The Tamron warranty guarantees you for five years which adds peace of mind too.

Still, an 825g lens coupled with a body in the region of 700g is not an insignificant weight to carry around.  You'll definitely be looking for a suitable neck or shoulder strap but with one, the weight and size are perfectly manageable for hours wandering around on holiday!  Attaching to a lighter APS-C camera does make it a little more front-heavy though.

As I expected, although from a Canon perspective this lens zooms the "wrong way", six months on it's something that I've adapted to and it's no issue at all.  Personally, it still feels wrong but while shooting I no longer miss shots because I'm used to twisting it in a different direction.

Image Quality

Shown below are some examples of the image quality of the lens - in all cases these are JPGs direct from camera with zero sharpening applied, albeit with the exception of the Milky Way photo which has been processed.  Some of them have been converted to black & white too; the point of my reviews are to use the camera in a real world scenario and show you what the lens is capable of, but in a context you could imagine using it yourself!

Here's a comparison of the lens at it's widest and also at full zoom.  As you can see, there is definite barrel distortion at 24mm that changes to pincushion at 70mm though both are easily corrected in Lightroom.  Visible also is a pronounced vignette at f/2.8 but as you can see it has practically disappeared by f/4 and has vanished long before f/8.  On the 24mm images this is easily observed on the 24mm shots bottom right with the car headlight and readily apparent on the 70mm shots.

f/2.8 @24mm

f/4 @24mm

f8 @ 24mm

f/2.8 @ 70mm

f/4 @ 70mm

f/8 @ 70mm

The maximum aperture of f/2.8 is definitely one of the reasons you buy this lens and the bokeh it's capable of is an important factor.  Generally I think it's pretty good, as evidenced by the images below, but I've shot the same scene at a range of apertures below so you can see for yourself.

f/2.8

f/4

f/5.6

f/8

f/11

f/16

f/22

The Vibration Control is rated at four stops of stability.  My experience is it does the job extremely well indeed and probably the best example I can share of how the VC let me capture a shot which would otherwise have been impossible is shown at right - I shot the Milky Way from a moving airliner with a 3.2 second exposure. Even with the ISO jacked up to 25,600 this shot would not have been possible without the impressive Vibration Control.  

Admittedly I shot a ton of throwaway frames but without a stabilised lens I wouldn't have even attempted this kind of image!

Sample Images

One of the many stray cats around Arab Street, shot wide open @ 70mm and f/2.8

Note the excellent eye & whisker sharpness but the pronounced vignette.  I think in this case the overcast conditions and shaded area behind the cat contribute but it does clearly show vignetting wide open.  For portraits this isn't necessarily a bad thing and is easily fixed in Lightroom.

Another wide open shot at 70mm.  This was taken seconds after the cat portrait and the lens had to go from one end of the focus range to the other.  As you can see it has nailed focus here in one shot.

This was the very definition of a snap-shot!  Taken at 35mm and f/4, this shopkeeper was sat in a dark and cluttered alcove but the AF quickly locked on.  Minimal vignetting is visible at f/4 and good sharpness across the scene.

At 1/30th sec the VC has helped steady the shot but some motion blur is still visible in the shopkeeper's hand.  Remember all the lens stabilisation in the world won't stop your subject moving!

Good sharpness is definitely possible even at the largest aperture available.  Even for "spiky" bokeh you can see it renders pretty nicely!

Flare is pretty well controlled.  I really had to push it to generate any flare at all and this is about the worst I ever see.  The orange smear at bottom right is another cactus plant that crept into frame!

Wide open at f/2.8, from Gardens By the Bay.  Though not a macro lens by any stretch, you can still get good results and make great use of the DOF wide open.

Common Tamron Complaints

It's worth touching on some of the complaints and issues that have affected Tamron lenses over the years - I'm guessing you're reading this review trying to balance the extremely competitive price of the Tamron vs your Canon/Nikon brand equivalent and you're worried about the reliability of a third-party lens.  Having used some earlier generation brand Tamron lenses a few years ago and swiftly returning them, I'm happy to report that the issues occuring in older Tamron lenses regarding soft/peculiar image quality issues simply aren't present.  Tamron seem to have invested significantly in their quality control and this lens - purchased retail, NOT a hand-picked review sample - has no fundamental flaws at all.  While Canon & Nikon have invested a huge amount more, and over a longer period, in their Quality Control Tamron have come on it leaps and bounds in this regard.  Backed up by 5 years of warranty means if you do chance on an unlucky dud you can still send it back for repair/replacement.

Likewise, auto-focus performance for third-party lenses from Tamron (and Sigma) was often unreliabe in older lenses.  This is another area that has seen great improvement but there are still niggling issues in this department.  Most of the time focus lands accurately but on occasion, inexplicably, it just misses by a country-mile and the shot is blurred.  Here are a couple of examples.

This was a reaction shot, granted a fairly clichéd one, but the AF appeared to lock through the viewfinder & I took the shot.  As you can see from the larger version, it's completely, hopelessly inaccuate!

Another extremely peculiar example.  Even though it was taken on a tripod and Garden's By the Bay is "wind-free", the focus here is just bizarre.  Shown also is a shot taken seconds later when normal service is resumed!

Still, sometimes the AF can pick out the correct subject in an extremely dense, "busy" subject field.  This is just one frame from a burst of 4 or 5 I shot, focused on a single thin branch with a cluttered background.  Each time it managed to lock onto the single branch I was aiming at, first time around.  As I've said, the AF is generally good and it's only the occasional peculiar example that stops it being great. 

Accuracy is one requirement of an AF system and the other is speed.  Many of my Canon lenses are quicker & similarly accurate but the Tamron does lag in this area.  Though not excellent it's certainly satisfactory.  For me, accuracy is generally more important than speed, particularly when a lens is paired to a body that isn't aimed at sports or action photographers.

It is worth noting though that Tamron reverse-engineer the auto-focus mechanisms in Canon & Nikon cameras.  Part of the reason the lenses are cheaper is that they don't pay a fee to the camera manufacturers to licence the AF to ensure 100% compatibility.  This potentially means that a lens working on your cameras today may not work on a future Canon camera body if they change how the auto-focusing works - something that happens infrequently, but has occurred in the past.  Quite probably this is a factor in the slower focusing speed of the Tamron and the occasional bizarre AF accuracy.

Six Months On 

I've now used this lens for a range of different subjects, including landscapes, studio portraiture, street scenes & travel.  In almost all cases it's been fantastic to use.  Although it does justifiably carry the label of a general purpose lens, I did find that using it while travelling I was wishing for a few extra millimetres of focal length.  The other logical option would be a 24-105 lens to meet that need but they are all saddled with an f/4 maximum aperture.  Personally, for my style of shooting, I prefer the options & look that come with an f/2.8 lens even if it means I have to take another lens away on holiday.  The only time I'd want a general purpose lens with a bit more reach is when travelling; for all other purposes I've valued the maximum aperture more.

If you're reading this trying to choose between an f/2.8 24-70mm or an f/4 24-105mm then the answer boils down to what you shoot more.  I know the feeling; I went through the same decision process myself!  For a street or portrait shooter, this lens has a lot of advantages over a 24-105mm.  For an "all-in-one" holiday lens where you might not use the wider aperture so much then maybe you'd be better served by the longer focal length.  Having more options in a single lens will save space & weight in your suitcase too.  As a travel lens, there are probably better options than this 24-70 and it all depends on where you're going & what you're shooting.

For me, size & weight are never an issue and I prefer the faster aperture.  eventually I'll look to compliment it with one of the 70-200mm f/2.8 zooms out there.  On photowalks around Singapore I've never yet found myself wishing for 105mm!

One thing did occur over time that was seriously annoying - the lens cap is less "grippy" than it was brand new and in Cambodia it fell off in my bag which subsequently saw the lens front element pick up a couple of tiny, superfine scratches.  They haven't impacted image quality in any noticeable way but it's still frustrating.

Conclusion

It's probably apparent already that I rate this lens highly indeed.  Image quality is great, the focal length range is useful for a large number of uses and the thing is built like a tank.  The Canon 24-70 II certainly has the edge from an image quality perspective but the Tamron has price & stabilisation on it's side.  On balance, considering the law of diminishing returns I doubt many people will have opportunities that showcase the higher quality the Canon offers or truly notice any different between the different lenses.  In a real-world environment the stabilisation from the Tamron pays dividends though; I rarely wish my images were just a little sharper but I *do* often wish I had IS on lenses that lack it!

The biggest deciding factor for me is the price.  The Tamron in many regions is less than half the price of the Canon - when I can get two lenses for the price of one, it tends to be a huge factor in favour of the cheaper lenses.  In this case, the Tamron is a winner.

Pros

  1. Great image quality & Vibration Control extremely useful
  2. Solidly built & reliable
  3. Competitive price

Cons

  1. AF potentially not future proof, slower than Canon & occasionally throws a hissy fit
  2. Some may find it heavy/bulky
  3. Rubbish lens cap!

Overall, the biggest compliment I can give is I love the lens so much I've now bought my own personal copy!

How I Review

Although looking at MTF charts and DxO statistics is an important measure in judging lens quality, I like seeing real-world, hands-on reviews of a lens in an environment I could imagine myself using it.  Technical & theoretical attributes are definitely important but I prefer to try to expose equipment to a range of different usage situations and see how it holds up.  

Reviewed in March & December 2014.  Review samples - first unit rented, second unit was purchased retail.