Sharpness and contrast
Let’s have a look at the theoretical performance of the new Tamron 17-35mm first and compare it to the performance of the Nikon 18-35/3.5-4.5G and the Tamron 15-30mm f2.8 VC:
These MTF charts show the computed lens-performance of lenses wide open without influence of diffraction. Higher values are better (more contrast) and the closer the line-pairs are together the less astigmatism (= resolution depends on the orientation of the test-pattern) the lens has. The x-axis displays the distance from the optical axis (=center of the sensor) in mm. I’ll show you the real-life performance at 4 mm (center), 13 mm (APS-C/DX-corner), and 20 mm (FF/FX-corner) on a 46MP Nikon D850 body.
From the charts the new Tamron 17-35mm should have an advantage over the Nikon and the Tamron 15-30mm within the APS-C/DX image-circle. Outside performance drops clearly towards the corners of the FF/FX sensor but stays above the Nikon. Only the Tamron 15-30mm should be better at the short end and of similar quality at the long end which is a bit unfair as the Tamron 15-30mm is shown here at f2.8 while the new Tamron 17-35mm is shown at f4.0.
Let’s see how this theoretical performance translates into real life results in the sharpness test based on Siemens-stars. Processing was done in Lightroom 7.5/CRAW 10.5 from RAW to Adobe Color profile. Noise-reduction is set to 0, sharpening to 50/0.5/36/10, with no extra tone, color, or saturation adjustment. White-balance was adjusted to a neutral white and I did some exposure compensation to make the brightness of all crops match. So you will not see light fall-off in the corners. Removal of lateral color aberrations is ON, longitudinal CA are not corrected.
The following are all 100% crops!
First up is an overview of the wide-open performance at different focal lengths. You can jump to the detailed results at different apertures and comparisons with the competition by clicking on the crops of the respective focal length (except for 24mm focal length where the results are not much different from 28mm).
Tamron’s new lens is very sharp in the center throughout the zoom-range. The APS-C/DX-corner is sharpest at 21mm and softens a bit towards the long end while the FF/FX-corner is the other way around: sharpest at the long end and softens up a bit below 24mm focal length. It has to be noted though that to achieve the best performance in the FF/FX-corner requires a bit different focus from the rest of the sensor area as the lens shows some clear field curvature.
If you want to see all the details and comparisons with the competition, read on. Or you can fast-forward to the performance at long distances.
The following 100% crops for each focal length show the new Tamron 17-35mm from wide open down to f11 with the competition interspersed at their comparable aperture.
Performance at 17mm:
The Nikon and the Tamron 15-30mm is included in this group at 18mm focal length for comparison.
At f2.8 the new Tamron 17-35mm is a little sharper than the Tamron 15-30mm in the crop taken 4mm off-center. In the APS-C/DX corner (13mm off-center) though the Tamron 15-30mm has a slight lead and it is clearly better in the FF/FX-corner (20mm off-center). At f4.0 the performance of the new Tamron 17-35mm is ahead of the Nikon across the full-frame sensor. The Tokina can keep up with the new Tamron in the APS-C/DX image-circle but clearly loses out in the FF/FX-corner.
Performance at 21mm:
Similar performance ranking at 21mm focal length.
Performance at 28mm:
Performance at 35mm:
With the Tamron 15-30mm f2.8VC now out of the picture the new Tamron 17-35mm takes the clear lead at the long end. The Nikon can keep up quite well in the APS-C/DX image-circle but its FF/FX-corner is clearly softer (as is the case at the other focal lengths too). The Tokina is its weakest at 35mm with the softest APS-C/DX-corner and ugly astigmatism spoiling the FF/FX-corner.
Overall Tamron’s newly designed 17-35mm zoom proves its merit against my reference zoom in this class, the Tamron 15-30mm f2.8VC, in the APS-C/DX image circle. There it is sharp and contrasty wide open over the complete focal range. But it lacks in the FF/FX-corner even if you correct focus for the field curvature the lens exhibits. To counter this you have to stop down to f5.6 which still leaves residual signs of astigmatism at the short end. The Tamron 15-30mm is clearly better corrected in this respect with less astigmatism and almost no field curvature in the outer reaches of a full-frame sensor. The Nikon 18-35mm offers also a very decent performance close to but always trailing a bit behind the new Tamron 17-35mm. The Tokina is very good at the short end keeping up with the new Tamron in the APS-C/DX image-circle at 17mm. But as soon as you zoom towards the long end the lens starts to fall behind its competitors. Overall I’d rank the Tokina last in this test at close distances.
Performance at long distances
The Siemens-star test-targets are shot at a distance of 45x focal length (i.e. at 1.6 m for 35 mm focal length). But performance of lenses also depends on the shooting distance. Therefore I present another series of test-shots of a city around 1 km away on a D850. Processing was done in Lightroom 7.5/CRAW 10.5 from RAW to Adobe Color profile. Noise-reduction is set to 0, sharpening to 50/0.5/36/10, with no extra tone, color, or saturation adjustment. There’s no tinkering with vignette-control so you see it here as it is produced by the lens. I used manual focus in live view optimized for the center at the largest aperture and did not change focus for other apertures. All shots were made at ISO 64 and VR switched off.
First up is an overview of the wide-open performance at different focal lengths. You can jump to the detailed results at different apertures and comparisons with the competition by clicking on the crops of the respective focal length (except for 24mm which was not so much different from 28mm). As usual I have selected the diagonal that provided the better corner results as almost any lens is a bit decentered.
In this long-distance test the new Tamron 17-35mm shows (again) very good performance in the center. But the APS-C/DX-corner at 17mm and 24mm looks a bit softer than in the previous test although the FF/FX-corner is holding up pretty well throughout the zoom range considering the field curvature the lens exhibited at shorter distances. If you want to see all the details and comparisons with the competition, read on. Or fast-forward to the next chapter on vignetting.
The main image shows the complete scene wide open to give you an impression of the angle of view and to judge vignetting. You can access the respective shots up to f11 via the links beneath the main image. Following the main image are 100% crops from the center, the APS-C/DX-corner and the FF/FX-corner wide open from the new Tamron 17-35mm and the competition to compare performance and then from the new lens at f4.0 down to f11. All lenses were shot on the same day except for the Tamron 15-30mm which was shot another day under somewhat clearer conditions.
You can click on each image to access the large original. Please respect our copyright and only use those images for personal use.
Results at 17mm focal length:
The Nikon and the Tamron 15-30mm is included in this group at 18mm focal length for comparison.
Results at 21mm:
Results at 35mm:
To make it easier to compare light fall-off in the corners of a full-frame sensor I’ve arranged a series of three shots each with the new Tamron, the Nikon and the Tokina at different apertures. All images were developed to the same brightness in the center. The first comparison is at 17mm/18mm focal length, the second at 24mm:
Light fall-off is worst at the short end which was to be expected. Comparing the three lenses at 24mm the Tamron has slightly less vignetting than the Nikon at f4.0 but a little more at f5.6. The Tokina shows the strongest vignetting. At 24mm the differences are smaller but the Tokina now is better than the Nikon at f4.0.
Rendering of point-light sources at night-shots
Night-shots pose a different challenge for lenses as the contrast is even higher than under bright sun and point-light sources can reveal some weaknesses such as coma, haloing and color-aberrations that do not show up as prominently in other test-shots. The 100% crops below the main image show the effect of coma in the FF/FX-corner of the new Tamron 17-35mm and the alternatives at various apertures at the wide end:
On the short end the new Tamron 17-35mm has a little more coma than the Tamron 15-30mm (shown here at 15mm) but less than the Nikon and the Tamron.
Coma at the long end:
On the long end the Tamron 15-30mm (shown here at 30mm) again is the clearest followed be the Tokina. The new Tamron 17-35mm places only third but is still clearly better than the Nikon.
Rendering of out-of-focus point-light sources
This test is for the rendering of point-light sources in an out-of-focus background. The circle of confusion that is produced by this test is pretty indicative of Bokeh performance (in the background) and light fall-off. Ideally the out-of-focus image of the point-light is evenly lit and perfectly circular, with no “onion-rings”, and without coloration. Large aperture lenses normally produce an effect known as “cat’s eye” the further away from the optical axis the point-light is projected. This is due to optical vignetting in the lens barrel when light enters the lens from an angle.
All images were shot at the longest focal length and largest aperture. The new Tamron is first followed by its rivals.
None of these lenses produces big Bokeh balls. The lead in terms of size has the Tamron 15-30mm which profits from its large f2.8 focal ratio although it only goes to 30mm focal length. But it suffers from outlining, onion rings and some deformation of the circular shape towards the corners. The new Tamron 17-35mm comes in second regarding size plus it offers a pretty smooth interior of its Bokeh balls despite employing aspherical lens elements. There is also only little outlining and almost no deformation of the circles towards the corner. The Nikon 18-35mm looks similar to the Tamron 17-35mm albeit with slightly smaller circles, more outlining, a more nervous inner structure and a stronger deformation toward the corner. The Tokina is similar to the Nikon but shows even more pronounced outlining in the center.
Now let’s see how this analysis of out-of-focus point-light sources translates into Bokeh-performance shooting a book-shelf.
Comparing the lenses at their longest focal length and largest aperture these test shots reveal almost no difference between them. I personally find the transition zone (middle crop) of the Tamron 15-30mm just a little softer than from the new Tamron 17-35mm while the new Tamron 17-35mm has a little softer background (right crop). The Nikon and the Tokina perform very similar with the exception of the foreground from the Nikon (left crop) which is the least blurred of all four lenses.
Flare, ghosting, and sun-stars
Catching a strong light-source shining directly into the lens is always a risky business especially with ultra-wide angle lenses. It could produce strange colorful ghost-images or reduce contrast considerably through flare and glare. The appearance of flare and ghosting depends on factors like the aperture and the angle of the light hitting the lens. So to judge the proclivity of the new Tamron 17-35mm for these artifacts I went through a series of well calculated shots against a strong light source to provoke glare and ghosting.
The new Tamron 17-35mm is amazingly clear of flare and glare artifacts at the short end and at the long end it doesn’t do too bad either. And outside these artifacts the new lens renders a deep black, so there’s little veiling glare.
See below some of the more obvious examples at 17mm and 35mm focal length:
The sunstars produced by the new Tamron 17-35mm improve further when stopped down to f11 or f16 (shown slightly cropped below):