Tamron 24-70 Review

Bright full frame standard zoom for Canon and Nikon: Tamron SP 24-70 mm F2.8 Di VC USD G2 (Model A032)

From time to time, we select nice lenses to test on a camera. This is not always easy, especially with lenses from third-party manufacturers such as Tamron or Sigma, since a suitable camera must be in my office at the same time. Likewise, lenses and cameras are a scarce test material. With the Tamron SP 24-70mm F2.8 Di VC USD it worked, and we could measure it on the Canon EOS 5D Mark III.

With the SP 24-70 mm F2.8 Di VC USD G2 (model A032) Tamron announces the second generation of its bright standard zoom for full format DSLRs from Canon and Nikon, but no longer for Sony. The G2 now has a nano coating to reduce reflections and a dirt-repellent fluor coating on the front lens. In addition, the autofocus and image stabilizer are now more powerful.

A nanocoating of the Tamron SP 24-70 mm f2.8 Di VC USD G2 (A032) should provide fewer reflections, an MTF tester for higher image quality in series production. [Photo: Tamron]

The optical design of the Tamron SP 24-70 mm F2.8 Di VC USD G2 continues to consist of 17 lenses arranged in twelve groups. Two XR elements (Extra Refractive Index), three LD elements (Low Dispersion), three GM elements (Glass-Molded aspherical) and one hybrid aspheric element are to ensure high image quality in the entire zoom range at high luminous intensity. Chromatic aberrations are thus to be reduced to a minimum with uniformly high image quality over the entire image area. All lens elements are provided with an advanced eBAND coating, which combines multiple coating with nanocoating. This should lead to an extremely low refractive index and an effective antireflection coating of the lens surfaces in order to ensure the highest image quality with high contrasts even with backlighting.

The lens construction is sealed against splash water and dust, the front lens has a dirt-repellent fluorine coating, which makes the lens easy to clean. New is the control system using a Dual-MPU (Micro Processing Unit). Two microprocessors control the image stabilizer and the ultrasonic autofocus independently of each other; previously, this was done by a single processor. This should provide an even more precise and faster autofocus, especially in darker environments. Thanks to its own processor, the optical image stabilizer even achieves an effectiveness of five f-stops according to the CIPA standard, which is currently the highest value for such a lens.

The Tamron SP 24-70 mm f2.8 Di VC USD G2 (A032), here with Canon connection, has an electromagnetic aperture and two processors to operate autofocus and image stabilizer independently and more effectively. [Photo: Tamron]

The Tamron SP 24-70 mm f2.8 Di VC USD G2 (A032) will be available from the beginning of August 2017 at a price of almost 1,700 Euro with Canon-EF and Nikon-F connector (to be seen here). [Photo: Tamron]

Tamron has also developed a unique MTF tester specifically for this lens, which is used in production to ensure uniform optical performance in series production. Tamron wants to meet the demand for high image quality in this way. The Tamron SP 24-70 mm F2.8 Di VC USD G2 is by the way compatible with the TAP-in console, which not only allows firmware updates, but also some adjustments of the lens, such as the manual intervention into the automatic focusing possible at any time. The closest focusing distance is 38 centimeters, which allows a maximum magnification of 1:5 to be achieved. The screen consists of nine rounded lamellas, which should provide by the nearly circular opening for a beautiful Bokeh.

From the beginning of August 2017, the Tamron SP 24-70 mm F2.8 Di VC USD G2 will be available at a price of almost 1,700 Euro with either Nikon or Canon connection. The Sony version, on the other hand, which still existed in the predecessor model, is omitted. The version with Nikon connection has, by the way, an electromagnetic aperture control, which is supposed to lead to a more precise exposure, as it has been usual with Canon for a long time. The scope of delivery includes the lens hood and a lens bag.

Our Test

It can be regarded as a shortcoming that the camera’s internal corrections of chromatic aberration and vignetting as well as distortion with lenses from third party manufacturers do not work. All the more reason for them to try to correct their lenses well in order to keep up with the quality of the original lenses. Because although the Tamron with 1.100 EUR is much cheaper than the comparable Canon, which costs 2.100 EUR or the Nikon, which still costs 1.500 EUR (but is not equipped with an image stabilizer), 1.100 EUR is still a lot of money. On the technical side, the Tamron with its quiet ultrasonic drive, high luminous intensity, high-quality processing and built-in image stabilizer does not need to hide behind.

The edge darkening is easily visible at all focal lengths in the corners of the image with an open aperture; it is most noticeable with about 1.5 f-stops (approx. 65 % light loss) in the wide angle. The edge darkening at 45 and 70 millimeters is very low by one step, in the wide angle of 24 millimeters, one should also stop down one step further, i.e. to F5.6, if a small loss of light at the edge of the picture is important. However, the original lenses are only ahead here because the camera corrections are activated by default and work well. In absolute terms, the vignetting of the Tamron is surprisingly low in view of the 35mm full format. At 2.5 percent, the distortion is most pronounced at wide-angle, while at 45 millimeters it reverses to the cushion shape, but is barely visible. At the end of the telegram, on the other hand, almost 1.5 percent of the pillow shape is reached. The amount is less than in wide-angle, but since the cushion shape is more unpleasant for human perception, it weighs just as much as the stronger barrel shape in wide-angle. Relatively, it can be said that the strength of the distortion for such a zoom is completely within the range. The comparable Nikon AF-S 24-70 mm 2.8 G IF ED, on the other hand, shows a much stronger wide-angle performance, with medium and long focal lengths comparable to the Tamron.

The Tamron on the EOS 5D Mark III does show chromatic aberrations, but on average they are hardly visible. However, the maximum values can already be noticeable and occur with the Tamron especially in the wide angle with open aperture. One step down they become more moderate. While the 5D Mark III has a very good correction for chromatic aberrations of original lenses, which unfortunately don’t work with the Tamron, the Nikon D800 lacks this correction or is not active by default. In addition, the Nikon AF-S 24-70 mm 2.8 G IF ED on the D800 tends to have more pronounced colour fringes than the Tamron on the Canon. Although the comparison is not as clear as the fact that the same image sensors are not used, it should be noted that the Tamron engineers have also done a good job in this respect.

But the most important thing about a high quality lens is its sharpness. Based on a 20 x 30 centimeter paper image, the Tamron is crisply sharp from the center of the image to the corners at all focal lengths and apertures. However, this also applies to the original lenses of the big manufacturers Canon and Nikon, because for a modern digital 35mm camera and a reasonably good lens, the size of 20 x 30 is not a challenge. It is more interesting to look at the MTF resolution at 50 percent contrast (see diagram below), as the weaknesses of the lenses are most clearly visible to the human eye in the contrast that is clearly perceptible. The Tamron SP 24-70mm F2.8 Di VC USD achieves almost 70 line pairs per millimeter (lp/mm) as the maximum resolution and thus plays in a league with other lenses that we have measured at the Canon and even comes close to the maximum values that we have measured at the nominally higher resolution Nikon D800. However, you have to fade out the tamron by about two f-stops. But even with an open aperture it shows a high resolution of a good 60 lp/mm at 24 and 45 millimeters in the image center, whereas in a telescope position you have to diagnose by two steps for more than 60 lp/mm. The average focal length of 45 millimeters shows the most uniform resolution across all apertures, only at F2.8 a clear loss of edge can be seen. At the maximum values, however, the average focal length lags slightly behind the others. In wide-angle, the drop in resolution at the edge is strongest in open-aperture and decreases continuously up to F11 or the resolution increases at the edge. The same applies to the telephoto focal length. In general, F11 is the most recommendable aperture when it comes to a uniformly high resolution from the center to the edge of the image, regardless of the focal length.

Bottom line

In summary, one can also certify that the Tamron can keep up with the original manufacturers when it comes to resolution. Of course there are differences in the resolution and other values in the details, sometimes the Tamron is a little better, sometimes a little worse. But in view of the much cheaper price of the Tamron SP 24-70mm F2.8 Di VC USD it is worth to consider it as an alternative, as despite the money saved one gets an equal image quality.

Manufacturer	Tamron
Model	SP 24-70 mm F2.8 Di VC USD G2 (A032)
Price (UVP)	1.699,00 EUR
Bayonet	Canon EF, Nikon F
Focal length range	24-70 mm
Luminous intensity (largest aperture)	F2.8 (continuous)
Smallest aperture opening	F22
Lens system	17 lenses in 12 group incl. ED and aspherical lenses
KB full format	yes
Number of orifice plates	9
Closest focusing distance	380 mm
Image stabilizer available	yes
Autofocus available	yes
Water/dust protection	yes
Filter threads	82 mm
Dimensions (diameter x length)	88 x 111 mm
Lens weight	905 g

Tamron SP 24-70mm F2.8 Di VC USD (A007) Datasheet

Manufacturer	Tamron
Model	SP 24-70mm F2.8 Di VC USD (A007)
Variants	Bayonet: Canon EF, Nikon F, Sony AF
EAN	4960371005591, 4960371005607, 4960371005614
Recommended price	1.349,00 €
Internet price	Check here
Focal length range	24-70 mm
Bayonet	Canon EF Nikon F Sony AF
Luminous intensity	F2.8 (continuous)
Smallest aperture opening	F22
Number of orifice plates	9
Autofocus	Focus motor in lens (ultrasonic motor)
Internal focusing	yes
Lens system	17 lenses in 12 group incl. ED and aspherical lenses
KB full format	yes
Water/dust protection	yes
Zoom motor	no
Image stabilizer	yes
Closest focusing distance	38 cm
Largest image scale	1:5,0
Filter threads	82 mm
Dimensions (Ø x length)	88 x 109 mm
Weight	825 g
Tripod clamp	no