In this review, I will talk about my month-long experience with the Tamron SP 24-70mm f/2.8 DI VC USD lens, provide detailed information on its characteristics along with image samples, as well as some optical measurements and comparisons to the Nikon 24-70mm f/2.8G lens.
1) Lens Overview
The Tamron 24-70mm f/2.8 is a versatile professional lens designed for many different kinds of photography needs – from wide-angle landscapes and panoramas, to portraits and events. Built with low-light photography in mind, the lens features a constant aperture of f/2.8, fast autofocus and built-in image stabilization (which Tamron markets as “VC” or “Vibration Compensation”). The latter is what no other manufacturers today, including Nikon and Canon, can pride themselves with – the Tamron 24-70mm is world’s first and currently only “standard zoom” lens with image stabilization (as of August 2012). Featuring 17 lens elements in 12 groups, 3 of which are aspherical and 3 with low-dispersion qualities, the Tamron 24-70mm f/2.8 has a more complex design than the Nikon 24-70mm f/2.8G, which has 15 lens elements in 11 groups. With a barrel diameter of 3.5 inches and weighing a total of 825 grams, it is by no means a small or lightweight lens. It incorporates Tamron’s Ultrasonic Silent Drive (USD) motor, which provides both fast and ultra-quiet autofocus.
With a focal length of 24-70mm (which is not its actual focal length, as pointed out in the “Lens Handling” section below), which is equivalent to roughly 36-105mm, it is designed to be used more on full-frame (FX) than cropped-sensor (DX) cameras. 36mm just might feel a little “too long” on the wide end on cropped-sensor cameras for general photography needs. Unlike most professional lenses that can take 77mm filters, the Tamron 24-70mm f/2.8 has a larger 82mm filter diameter, which means that it would require purchasing additional larger filters if you are planning to use filters on it. Due to the massive size of the front element, it would be impossible to use a 77mm filter with adapter rings.
In terms of optical performance, as you will see below in the Sharpness section, the Tamron 24-70mm f/2.8 delivers very good results. It starts out strong wide open at 24mm and weakens towards 70mm. On the flip side, the lens suffers from pronounced vignetting, has an onion-shaped bokeh and has field curvature issues at longer focal lengths.
2) Lens Specifications
- Fast, wide-angle to medium telephoto zoom lens with a constant aperture of f/2.8.
- Three glass-molded aspherical lenses and one hybrid aspherical lens to control chromatic aberrations while enhancing sharpness and contrast.
- Three low-dispersion (LD) lens elements for increased sharpness.
- Two extra-refractive index (XR) lens elements for reduced aberrations and better imaging performance.
- Tamron’s Ultrasonic Silent Drive (USD) provides near-silent high-speed auto focus with superb accuracy.
- AF/MF focus mode switch allows changing between manual and auto focus operation.
- Rugged construction with professional-grade dust and moisture resistance.
- Mount Type: Nikon F-Bayonet (also available for Canon and Sony mounts)
- Focal Length Range: 24-70mm
- Maximum Aperture: 2.8
- Minimum Aperture: 22
- Angle of View (DX-format): 60°20’ －22°33’
- Angle of View (FX-format): 84°04’ －34°21’
- Lens (Elements): 17
- Lens (Groups): 12
- Compatible Format(s): FX, DX, FX in DX Crop Mode, 35mm Film
- Diaphragm Blades: 9
- Distance Information: Yes
- LD Glass (Elements): 3
- Aspherical (Elements): 3
- Hybrid Aspherical (Elements: 1
- Autofocus: Yes
- USD (Ultrasonic Silent Drive): Yes
- Minimum Focus Distance: 0.38m
- Focus Mode: AF/MF
- Filter Size: 82mm
- Accepts Filter Type: Screw-on
- Length: 108.5mm (4.3 in)
- Full Length: 116.9mm (4.6 in)
- Diameter: φ88.2mm (3.5 in)
- Weight (Approx.): 29.1 oz. (825g)
- Lens Hood: Flower-shaped HA007 lens hood
3) Lens handling
Just like the Nikon 24-70mm f/2.8G, the Tamron 24-70mm f/2.8 feels very solid in hands. Although its barrel is made of plastic (versus the all-metal construction of the Nikon 24-70mm) it does not have a cheap or “plasticky” feel to it at all. Keep in mind that plastic does not expand and contract like metal does when temperatures change quickly, which can actually prolong the life and performance of a lens. All new Nikon AF-S primes, even the most expensive ones like the Nikon 24mm f/1.4G have plastic barrels and they handle exceptionally well. On top of that, plastic means lighter and as I have already pointed out earlier, the Tamron 24-70mm is lighter than the Nikon 24-70mm, despite the fact that it has a bigger barrel and a more complex optical design.
Similar to other 24-70mm lenses, the length of the lens extends when the focal length is changed. At the wide end @ 24mm, the lens is at its shortest length. As you zoom in, the length of the lens increases, reaching its longest length at 70mm. The Nikon 24-70mm behaves completely differently – its shortest length is at 50mm, while zooming out to 24mm extends the lens quite a bit. Take a look at both lenses at 70mm:
And here, you can see the Tamron 24-70mm at 70mm, while the Nikon 24-70mm is at 24mm – both lenses fully extended:
And lastly, here are both lenses at their shortest length, with Tamron 24-70mm at 24mm and Nikon 24-70mm at 50mm:
The zoom ring is pretty smooth out of the box with some resistance. Overtime, this resistance might weaken a bit, but I have not had the lens long enough to tell for sure. My Nikon 24-70mm was fairly good in the beginning and now the zoom ring is too smooth and somewhat loose – a result of heavy field use and abuse (I will be sending it to Nikon for tuning soon). The zoom and focus rings are reversed like on some Nikon lenses like Nikkor 24-120mm f/4 VR and the zoom ring is not as wide, which I am fine with.
While inspecting the lens, I found out that zooming in to 70mm causes the rear element to go deep inside the lens. While some movement of the rear element is quite normal on zoom and prime lenses, I found this one to be a little extreme. At 70mm, a lot of the lens guts are exposed, as seen in the below image:
There is nothing that protects the rear. In comparison, the Nikon 24-70mm f/2.8G has a single non-moving rear element that protects the lens. Keep this in mind when changing lenses, especially in dusty and windy environments. If you do decide to change lenses, make sure to zoom out to 24mm before you dismount it. On the positive side, similar to all recently-announced Nikon AF-S lenses, the Tamron 24-70mm f/2.8 also features a rubber gasket on the lens mount that minimizes the amount of dust that could potentially end up inside the lens or the camera.
Another interesting observation, was the focal length of the lens – the Tamron 24-70mm is not a true 24-70mm lens. When compared to the Nikon 24-70mm, it was a little wider throughout the zoom range. It was hard to quantify this difference, but I would say it was more like a 22-60mm lens instead (depending on focus distance). Personally, I would consider this as an advantage, because sometimes I wish the 24-70mm was a little wider. But I guess it all depends on what focal lengths you use the most. For landscape photography, I tend to stay between 24mm and 50mm for most of my landscape shots, so cutting it a little short on the long end does not bother me.
The Vibration Compensation (VC) switch, along with the AF/MF switch are both located on the side of the lens, similar to Nikkor lenses (the lens comes with VC turned off). There is another switch on the lens for locking the zoom at 24mm, probably used for transportation purposes and to prevent the lens from creeping in the future. All switches are easy to move and use. Tamron uses lens caps similar to the ones that Nikon uses, which is good news. I personally dislike Canon’s lens caps, because they are impossible to remove with a lens hood on.
The large barrel size and a massive front element result in an over-sized, non-standard (for pros) filter size of 82mm. I personally consider this as a cost disadvantage to the Tamron 24-70mm f/2.8, because standard 77mm filters cannot be used with step ring adapters. So when deciding whether to purchase this lens, add the cost of circular filters that you might need to purchase as well. If you use a filter holder system, make sure that your filter holder can accommodate the lens, perhaps with other adapters. I use Hi-Tech and Lee Filter Holder systems and both have 82mm adapters, so it is just a matter of purchasing the right adapter. Thanks to the rear focus design, the front element of the lens does not extend or rotate during focusing, so you don’t have to worry about constantly readjusting filters like on some older lenses.
Although the lens is heavy, it balances quite well on heavier pro bodies like Nikon D800/D4. The same is not true on entry-level cameras like Nikon D3200 – it certainly feels off-balance towards the front of the lens and awkward, due to its size and weight. While it works great on any DX camera, I would not recommend to use it on one, unless you like working in the 36-105mm range. Cheaper and lighter alternatives like Nikon 16-85mm or Nikon 16-35mm VR would be more useful in terms of focal length and size.
The HA007 bayonet lens hood is wider, but much shorter than the HB-40 that goes on the Nikon 24-70mm, as seen in the below picture:
It snaps on nicely, stays in place and does not wobble. I highly recommend to keep it on the lens at all times, because it does help in dealing with lens flare and it can come in handy for protecting the front element. While storing or transporting the lens, you can conveniently reverse the hood and it won’t take up any additional space.
4) Focus acquisition speed and accuracy
The Tamron 24-70mm f/2.8 features the Ultrasonic Silent Drive (USD) autofocus motor that is used in high-end Tamron lenses. It is very fast, accurate and produces very low noise during AF operation. In comparison, the Nikon 24-70mm f/2.8G is both faster and quieter, but not by a big margin. In fact, to date I have not seen any lens for the Nikon mount that focuses faster than the Nikon “trinity” (14-24mm, 24-70mm, 70-200mm). But this speed advantage is not that big of a deal, since the speed of the Tamron 24-70mm is more than adequate for any kind of photography. The key in autofocus performance is precision and low-light performance and the Tamron 24-70mm surely does not disappoint in both. Lola and I shot a few weddings with this lens and it performed quite well even in very dim environments.
5) Vibration Compensation / Image Stabilization
The key advantage of the Tamron 24-70mm f/2.8 over all other 24-70mm lenses on the market today is its image stabilization feature, which Tamron calls “Vibration Compensation”. Tamron claims that the VC technology provides up to 4 stops of stabilization, similar to Nikon’s claim on its VR II technology. I personally found the 4 stop claim to be an overstatement for both VC and VR II, especially on high resolution cameras like Nikon D800 and D7000. Realistically, I would say that both VC and VR II provide up to about 2.5-3 stops of advantage, with the latter being a little more consistent.
Overall though, image stabilization on a 24-70mm zoom range is a huge bonus. Many photographers blindly think that they do not need stabilization on short focal length zoom lenses. First of all, this is a “standard” zoom lens and second, image stabilization is extremely useful even on super wide-angle lenses. Try the Nikon 16-35mm VR or any of the new Canon wide-angle primes with IS and you will see what you have been missing all along…
6) Lens sharpness and contrast
Some of the weaknesses of the Nikon 24-70mm f/2.8G, are its rather soft corner performance at large apertures and optical issues such as distortion and vignetting at the shortest zoom range of 24mm. One needs to be aware of these limitations and I personally often avoid using the Nikon 24-70mm at 24mm and large apertures. The Tamron 24-70mm f/2.8, on the other hand, has a completely different optical design that is actually optimized for wide open performance at 24mm. In fact, the Tamron 24-70mm f/2.8 turned out to be a reverse version of the Nikon 24-70mm: as you will see in the next page of this review, it is sharpest at 24mm and its performance deteriorates towards 70mm, with the worst performance at the longest zoom range.
In addition, the lens exhibits odd behavior when stopping down to f/4 from f/2.8 on certain samples. The image gets brighter and its diaphragm blades do not seem to change much between these apertures. At first, I thought the error was on my end, but as I tested the lens in different environments, I was able to reconfirm this behavior. You can see a clear example of this problem in the next “Bokeh” section below. So f/4 is not really f/4 on this lens. I thought it was just my lens sample that was showing this particular problem, but it turned out that I was not the only one – another local photographer who owns the same lens also had the same problem. It is hard to say how many samples out there have this particular problem, so I would encourage you to check your sample quickly and exchange it for a good one within the return window.
As for contrast and colors, I found them to be similar to the Nikon 24-70mm, which is superb. With such a complex design and so many aspherical and low dispersion elements, it had better be!
7) Field curvature
The Nikon 24-70mm f/2.8 suffers from pronounced field curvature issues, as I have already pointed out in my Nikon 24-70mm review. The donut-shaped field curvature it exhibits is rather annoying at large apertures, with decreased mid-frame performance on FX, which is pretty close to where the corner frame on DX is. In comparison, the Tamron 24-70mm f/2.8 does not have major field curvature issues at 24mm, but does have the same donut-shaped curvature at 50mm and longer. This can be clearly seen from the Imatest charts provided in the second and third pages of this review, where you can spot a drop of mid-field performance at focal lengths above 24mm.
When it comes to bokeh performance, the Tamron 24-70mm shows some interesting characteristics. Take a look at the below comparison between the Tamron 24-70mm f/2.8 and the Nikon 24-70mm f/2.8G:
As I have pointed out in the above section (Lens sharpness and contrast), you can clearly see what happens to the bokeh shape and size when the lens is stopped down from f/2.8 to f/4.0. There is practically no difference between the two apertures – only brightness changes (had to compensate by -1 stop in Lightroom to make the above images comparable). Bokeh shape and size stay exactly the same. Now take a look at the Nikon 24-70mm f/2.8G on the bottom and note how different it looks between apertures.
Now a few observations of bokeh performance:
- Both lenses show pronounced outlines of out of focus highlights
- Similar to some Sigma lenses (see the Sigma 50mm f/1.4 Review), the Tamron 24-70mm shows a thicker, non-uniform outline and an “onion-shaped” bokeh – a result of the different aspherical lens elements used in the lens
- The bokeh of Nikon 24-70mm looks smoother and less distracting in general
And now let’s take a look at how both lenses do with bokeh in front of the focused area:
No need to describe the situation here – you can clearly see which one is better.
Overall, neither lens shows exceptional bokeh performance, but the Nikon 24-70mm is clearly better than the Tamron 24-70mm. The onion-shaped bokeh can be quite distracting on the Tamron 24-70mm and you can see the effect in both bokeh comparisons. If you are looking for a good portrait lens with beautiful bokeh, try the Nikon 85mm f/1.4G instead.
Vignetting on the Tamron 24-70mm is most pronounced wide open at 24mm. As the focal length increases and the lens is stopped down, the amount of vignetting is reduced substantially, as can be seen below:
And here is a a graph that shows the spread of light falloff across the image frame at 24mm, f/2.8 (worst vignetting levels):
10) Ghosting and Flare
The Tamron 24-70mm f/2.8 handles ghosting and flares quite well, as can be seen below (taken without the hood and without any filters):
And here is the Nikon 24-70mm f/2.8G in comparison:
From the above two image samples, the Tamron looks better to me overall. While the Tamron shows a little more flare, the Nikon 24-70mm shows a lot more ghosting throughout the frame. That’s why the Nikon 24-70mm has a huge lens hood – it just does not do well against very bright light sources. You could take off the lens hood on the Tamron 24-70mm and you would be fine, whereas I would not recommend to do the same on the Nikon 24-70mm.
The Tamron 24-70mm f/2.8 starts out with moderate barrel distortion at the shortest focal length of 24mm that Imatest measured at -3.74%. It then immediately switches to pincushion distortion at 35mm and stays that way until 70mm, as illustrated below:
I personally do not worry about distortion problems on my lenses, because they are very easy to fix in Photoshop and Lightroom. The latest version of Lightroom 4 already has built-in support for the Tamron 24-70mm f/2.8, so the issues can be fixed with a single click using the Lens Correction module.
12) Chromatic Aberrations
Chromatic aberrations are practically non-existent in the center frame at all focal lengths and apertures. In the extreme corners, however, some CA is present depending on the focal length and aperture. Interestingly, the lowest amount of CA is at largest apertures (except for 24mm), as shown below:
Similar to distortion, chromatic aberrations are also easy to deal with in post-production, so I would not be overly concerned about the above numbers.
Let’s now move on to the good stuff – sharpness tests and comparisons. Select the next page below.
13) Sharpness Test
Take a look at the following sharpness charts that illustrate the optical performance of the Tamron 24-70mm f/2.8 at different focal lengths from 24mm to 70mm:
As noted earlier, the Tamron 24-70mm shows strong performance at the shortest end of the zoom range. It has excellent center and mid-frame performance at all apertures, with f/5.6 yielding the best performance. Its corner performance is also quite good, with best resolution figures at around the f/8 mark.
As the focal length increases, the overall sharpness of the lens starts to suffer a little. The center and mid-frame stay pretty strong at f/5.6 and f/8.0, but the corners do take a slight hit.
At 50mm, the corner resolution improves slightly, but the center yields slightly worse figures than shorter focal lengths.
And at 70mm, the lens is at its worst at all large apertures, with f/11 yielding the best numbers. There is a some straight field curvature that affects the extreme corners at all focal lengths, but it is not as bad as in some lenses.
14) Compared to Nikon 24-70mm f/2.8G
The Nikon 24-70mm f/2.8G has been my favorite landscape lens for a while now, as noted in my Nikon 24-70mm Review. I love its tough build and super fast AF, both of which have been quite useful when shooting professionally. However, its lack of image stabilization and a number of optical issues have made it tough to keep shooting with it, especially when lenses like Nikon 24-120mm f/4 VR are available today. When Tamron announced this 24-70mm, I really wanted to see how it would compare optically to my Nikon 24-70mm. Let’s take a look.
15) Tamron 24-70mm vs Nikon 24-70mm @ 24mm
The Nikon 24-70mm f/2.8G is an extremely sharp lens in the center of the frame, even at the largest apertures. However, its donut-shaped aperture (quite noticeable on a flat surface) makes it suffer in the mid-frame, as shown in the below illustration. It also has rather poor corner performance even when stopped down at 24mm, which is its weakest focal length:
16) Tamron 24-70mm vs Nikon 24-70mm @ 35mm
At 35mm, the Nikon 24-70mm f/2.8G improves dramatically. While it starts out weaker in the mid-frame and corners, stopping down to f/5.6 produces sharp images across the frame, with f/8.0 having the best overall performance:
17) Tamron 24-70mm vs Nikon 24-70mm @ 50mm
As we zoom in more to 50mm, the Nikon 24-70mm now performs better at all apertures:
18) Tamron 24-70mm vs Nikon 24-70mm @ 70mm
Finally at 70mm, the Nikon 24-70mm still outperforms the Tamron 24-70mm at the largest apertures, with a slightly weaker performance beyond f/8:
19) Tamron 24-70mm vs Nikon 24-70mm Summary
The Tamron 24-70mm shows impressive performance at the shortest focal length of 24mm. It has excellent sharpness across the frame and it clearly beats the Nikon 24-70mm at all apertures. However, as the Nikon 24-70mm is zoomed in beyond 24mm, it produces better resolution across the frame. While Tamron starts out strong at the shortest focal length and weakens towards the telephoto range, the Nikon shows a completely reverse picture. Except for 24mm, the Nikon is clearly better, especially when stopped down to f/5.6-f/8. It also produces smoother bokeh and has a little less vignetting problems to deal with. At the same time, the Nikon 24-70mm suffers from heavier distortion issues (stronger barrel distortion at 24mm and pincushion distortion at all other focal lengths), has a little more chromatic aberration issues in the extreme corners and lacks image stabilization. So when choosing between the two lenses, I would recommend to weigh in what is more important for you, keeping the cost difference in mind.
20) Compared to Nikon 24-85mm f/3.5-4.5G VR
Priced at $669, the new Nikon 24-85mm f/3.5-4.5G VR might seem like a good alternative to the Tamron 24-70mm. It is also a full-frame lens with integrated image stabilization (VR II) technology and it gives slightly more zoom range to work with on the long end. Let’s take a look at how it compares in terms of sharpness on the high-resolution Nikon D800.
21) Tamron 24-70mm f/2.8 vs Nikon 24-85mm VR @ 24mm
As you can see, the Nikon 24-85mm VR does not stand a chance against the Tamron 24-70mm at 24mm – it has much weaker center, mid-frame and corner resolution:
22) Tamron 24-70mm f/2.8 vs Nikon 24-85mm VR @ 35mm
At 35mm, the Nikon 24-85mm has slightly better center sharpness, but it lags behind in mid-frame and corner performance, as shown below:
23) Tamron 24-70mm f/2.8 vs Nikon 24-85mm VR @ 50mm
We see a similar situation at 50mm – the Nikon 24-85mm is still worse in mid-frames and corners:
24) Tamron 24-70mm f/2.8 vs Nikon 24-85mm VR @ 70mm
And at 70mm, the Nikon 24-85mm VR yields better center sharpness, although the mid-frame and the corners are somewhat comparable. The Tamron takes over at f/11, with better resolution throughout the frame:
25) Tamron 24-70mm f/2.8 vs Nikon 24-85mm VR Summary
Except for the telephoto range of 70mm, the Nikon 24-85mm VR clearly falls behind the Tamron 24-70mm f/2.8 in terms of resolution. This is especially noticeable in the mid-frame and corners, where the Nikon 24-85mm VR just does not do well, period. In addition, the Nikon 24-85mm has a bunch of other optical issues – it has more vignetting, distortion and chromatic aberration problems, especially at shorter focal lengths. You certainly get what you pay for…
Summary and Image Samples
Being the first image-stabilized Full Frame standard zoom lens in the world, the Tamron SP 24-70mm f/2.8 DI VC USD has been receiving quite a bit of attention from the photography community ever since it was announced in April of 2012. Lack of image stabilization has been one of the major drawbacks of 24-70mm lenses for Nikon and Canon mounts for a while now and many photographers and especially videographers, have been desperately waiting for such a lens. Given the fact that Canon released a Mark II version of the Canon 24-70mm earlier this year without image stabilization, we might not see stabilized 24-70mm lenses from the big brands for a while now.
While having image stabilization is certainly a huge bonus, it is only one of the criterion for choosing lenses. The lens also has to perform well optically and that’s where the Tamron 24-70mm has its strengths and weaknesses. As seen in the “Sharpness Test” and “Lens Comparisons” pages, the Tamron 24-70mm f/2.8 shows excellent performance at 24mm, surpassing the Nikon 24-70mm in mid-frame and corner performance (mostly due to the donut-shaped field curvature the Nikon 24-70mm exhibits). In addition, the lens shows less ghosting, distortion and chromatic aberration issues than the Nikon 24-70mm at pretty much all focal lengths. However, the sharpness of the Tamron 24-70mm quickly deteriorates as the lens is zoomed in, so the Nikon 24-70mm pretty much takes over at all focal lengths starting from 35mm. Still, the Tamron yields good sharpness across the frame, especially when compared to lower cost lenses like the Nikon 24-85mm VR.
A key disadvantage of the Tamron 24-70mm is its ugly onion-shaped bokeh, an example of which you can see on the first page of the review. The Tamron 24-70mm is great for low-light situations with quick AF and image stabilization, but you have to be able to live with the way it renders the background highlights. Also, sample variation can be an issue. While my sample was pretty strong optically, it had an issue when changing aperture from f/2.8 to f/4, as evidenced from the same bokeh comparison. While third party lens manufacturers have gotten much better with their QA processes during the last few years, I still find them to have much more sample variation than Nikon and Canon. I have seen a number of cases, where identical lenses would perform completely differently in the same lab conditions.
Overall though, considering all advantages and disadvantages of the Tamron 24-70mm and the fact that it is $600 cheaper than the Nikon 24-70mm f/2.8G, I consider it a great buy. Tamron did a good job in designing this lens and as I have pointed out a number of times, image stabilization is certainly a big plus when comparing it to the much more expensive Nikon and Canon (Mark II) counterparts.
27) Where to buy and availability
28) More image samples
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