Quality

Longitudinal Chromatic Aberration and focus shift

I tested the Tamron 35-100mm f2.8 Di III at 100mm for longitudinal color aberrations (loCA, a.k.a. “axial color” or “bokeh CA”) and focus shift. The former can show up as magenta coloration in the foreground and greenish hues in the background and are not easily corrected in post-processing. The new zoom lens shows strong loCA when used wide open and focus shift towards the foreground is clearly visible:

Tamron 35-100mm f2.8 Di III loCA at 100mm; 50% crops from 180MP image

Above from top to bottom: f2.8, f4.0, f5.6; left = foreground, right = background; click image for 100% crops

The Tamron 35-100mm f2.8 Di III also shows some purple fringing around high-contrast edges in the focus plane and a bit of green outlining around background subjects. Spill-over of bright background light is relatively well controlled:

Above: Tamron 35-100mm f2.8 Di III at 100mm, f2.8; click here for large original

Sharpness and contrast

Let’s have a look at the theoretical performance of the new Tamron 35-100mm f2.8 Di III first and compare it to the Tamron 28-75mm f2.8 Di III G2 and the Nikon Z 24-120mm f4 S:

Above: MTF Tamron 35-100mm f2.8 Di III at 35mm f2.8 (left) and 100mm f2.8 (right)

Above: MTF Tamron 28-75mm f2.8 Di III G2 at 28mm f2.8 (left) and 75mm f2.8 (right)

Above: MTF Nikon Z 24-120mm f4 S at 24mm f4.0 (left) and 120mm f4.0 (right)

These MTF charts show the computed lens-performance wide open without influence of diffraction at 10 line-pairs/mm (in red/yellow) and 30 lp/mm (in blue/gray). Higher values are better (more contrast) and the closer the dotted and solid lines are together the less astigmatism (= resolution depends on the orientation of the test-pattern) the lens has. The x-axis displays the “image height” which is the distance from the optical axis (=center of the sensor) in mm. I’ll show you the real-life performance at 4 mm (near center), 13 mm (APS-C/DX-corner), and 20 mm (FF/FX-corner).

At the short end all three lenses look astonishingly similar with the Z-Nikkor showing a higher contrast at fine structures near the center but higher astigmatism outside the inner image circle. At the long end the Tamron 28-75mm has the most even sharpness across the full frame while the Z-Nikkor again looks sharper on paper in the center but suffers a steep decline in resolution towards the corners.

Let’s see how this theoretical performance translates into real life results in the sharpness test based on Siemens-stars shot on a 45MP Nikon Z8 set to 16 image pixel shift shooting. The 16 individual images for each shot were merged in NX Studio 1.9.1 into a 180MP RAW file and further processed in Lightroom 14.5/CRAW 17.5 to Adobe Color profile with the lens profile compensating CA, distortions and vignetting. Noise-reduction was set to 0, sharpening to 50/1/36/10, 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. I also focused separately for the center, the APS-C/DX-corner, and FF/FX-corner which eliminates any effect field-curvature might have. If you want to know more about the advantages and perils of pixel shift shooting head over to page 2 of my Tamron 28-75mm f2.8 Di III G2 Nikon Z review.

First up is an overview of the wide-open performance at different focal lengths (presented as 50% crops). You can jump to the detailed results at different apertures and comparisons with other lenses by clicking on the crops of the respective focal length.

Tamron 35-100mm f2.8 Di III; 50% crops from 180MP image near center, APS-C/DX-corner, FF/FX-corner

Above: 35mm, f2.8

Above: 50mm, f2.8

Above: 70mm, f2.8

Above: 100mm, f2.8

At the wide end Tamron’s 35-100mm f2.8 Di III looks very sharp across the full-frame sensor. Zooming in to 50mm softens the FF/FX-corner considerably. At 70mm also the APS-C/DX-corner is softening up a bit becoming outright soft at 100mm. Field curvature in general is not overly strong at normal shooting distances.

Detailed results

The following crops for each focal length show the Tamron 35-100mm f2.8 Di III wide open compared to the Tamron 28-75mm f2.8 Di III G2, Nikon Z 24-120mm f4 S (shot at 45MP on a Nikon Z7), and Tamron 70-180mm f2.8 VC G2 at 35mm, 50mm, 70mm, and 100mm. Or you skip the details and fast-forward to the summary for this chapter.

Performance at 35mm:

Tamron 35-100mm f2.8 Di III at 35mm compared; 50% crops from 180MP image near center, APS-C/DX-corner, FF/FX-corner

Above: Tamron 35-100mm f2.8 Di III at 35mm, f2.8; click image for full resolution 100% crops

Above: Tamron 28-75mm f2.8 Di III G2 at 35mm, f2.8; click image for full resolution 100% crops

Above: Tamron 35-100mm f2.8 Di III at 35mm, f4.0; click image for full resolution 100% crops

Above: Nikon Z 24-120mm f4 S at 35mm, f4.0; shot at 45MP on a Nikon Z7

Above: Tamron 35-100mm f2.8 Di III at 35mm, f5.6; click image for full resolution 100% crops, also available at f8.0

At 35mm the Tamron 35-100 is the sharpest lens across the full frame.

Performance at 50mm:

Tamron 35-100mm f2.8 Di III at 50mm compared; 50% crops from 180MP image near center, APS-C/DX-corner, FF/FX-corner

Above: Tamron 35-100mm f2.8 Di III at 50mm, f2.8; click image for full resolution 100% crops

Above: Tamron 28-75mm f2.8 Di III G2 at 50mm, f2.8; click image for full resolution 100% crops

Above: Tamron 35-100mm f2.8 Di III at 50mm, f4.0; click image for full resolution 100% crops

Above: Nikon Z 24-120mm f4 S at 50mm, f4.0; shot at 45MP on a Nikon Z7

Above: Tamron 35-100mm f2.8 Di III at 50mm, f5.6; click image for full resolution 100% crops, also available at f8.0

At 50mm the Tamron 35-100 looks neck-and-neck with the Tamron 28-75 at f2.8 and the Nikon 24-120 at f4.0.

Performance at 70mm:

Tamron 35-100mm f2.8 Di III at 70mm compared; 50% crops from 180MP image near center, APS-C/DX-corner, FF/FX-corner

Above: Tamron 35-100mm f2.8 Di III at 70mm, f2.8; click image for full resolution 100% crops

Above: Tamron 28-75mm f2.8 Di III G2 at 75mm, f2.8; click image for full resolution 100% crops

Above: Tamron 70-180mm f2.8 Di III VC G2 at 70mm, f2.8; click image for full resolution 100% crops

Above: Tamron 35-100mm f2.8 Di III at 70mm, f4.0; click image for full resolution 100% crops

Above: Nikon Z 24-120mm f4 S at 70mm, f4.0; shot at 45MP on a Nikon Z7

Above: Tamron 35-100mm f2.8 Di III at 70mm, f5.6; click image for full resolution 100% crops, also available at f8.0

At 70mm the Tamron 70-180mm f2.8 Di III VC G2 delivers the sharpest results while the Tamron 35-100 is pretty close in the APS-C/DX image-circle at f2.8. At f4.0 the Nikon 24-120 might be a bit sharper in the center than the Tamron 35-100 but is clearly slightly softer at the DX-corner.

Performance at 100mm:

Tamron 35-100mm f2.8 Di III at 100mm compared; 50% crops from 180MP image near center, APS-C/DX-corner, FF/FX-corner

Above: Tamron 35-100mm f2.8 Di III at 100mm, f2.8; click image for full resolution 100% crops

Above: Tamron 70-180mm f2.8 Di III VC G2 at 100mm, f2.8; click image for full resolution 100% crops

Above: Tamron 35-100mm f2.8 Di III at 100mm, f4.0; click image for full resolution 100% crops

Above: Nikon Z 24-120mm f4 S at 120mm, f4.0; shot at 45MP on a Nikon Z7

Above: Tamron 35-100mm f2.8 Di III at 100mm, f5.6; click image for full resolution 100% crops, also available at f8.0

At 100mm the Tamron 70-180 delivers clearly superior results compared to the Tamron 35-100 even when the latter is stopped down to f4.0 where it performs comparably to the Nikon 24-120 (at 120mm).

Summary:

The comparisons show that the Tamron 35-100mm f2.8 Di III suffers from a degradation of resolution towards the long end: While it is the sharpest lens at the short end it’s “only” neck-and-neck with the others at 50mm. And the further you zoom in the more the lens profits from stopping down to 4.0 or f5.6 – for good sharpness of the FF/FX-corner even f8.0.

Performance at long distances

The Siemens-star test-targets are shot at a distance of 45x focal length (i.e. at around 4.5m for 100mm focal length). But performance of lenses also depends on the shooting distance. Therefore, I shot another series of a city around 1 km away on a Nikon Z8. The images were processed in Lightroom 14.5/CRAW 17.5 to Adobe Color profile with the the lens profile compensating CAs, distortions, and vignetting. Noise-reduction was set to 0, sharpening to 50/0.5/36/10, with no extra tone, color, or saturation adjustment. All shots were made from a heavy tripod with image stabilization switched off at ISO 64. As usual I have selected the diagonal that provided the better corner results as the lens was slightly decentered.

The following images show the complete scene wide open shot with the Tamron 35-100mm f2.8 Di III plus 100% crops from near center, APS-C/DX-corner, and FF/FX-corner. All crops in a row are from the same image so there is no compensation for field curvature. You can access the large 45MP originals, but the files are for personal evaluation only and cannot be used in another publication or website without permission.

Tamron 35-100mm f2.8 Di III at 35mm

Above: Tamron 35-100mm f2.8 Di III at 35mm f2.8; click image for 4k version, here for large original

Above: Tamron 35-100mm f2.8 Di III at 35mm f4.0

Above: Tamron 35-100mm f2.8 Di III at 35mm f5.6; crops also available at f8.0

Tamron 35-100mm f2.8 Di III at 50mm

Above: Tamron 35-100mm f2.8 Di III at 50mm f2.8; click image for 4k version, here for large original

Above: Tamron 35-100mm f2.8 Di III at 50mm f4.0

Above: Tamron 35-100mm f2.8 Di III at 50mm f5.6; crops also available at f8.0

Tamron 35-100mm f2.8 Di III at 70mm

Above: Tamron 35-100mm f2.8 Di III at 70mm f2.8; click image for 4k version, here for large original

Above: Tamron 35-100mm f2.8 Di III at 70mm f4.0

Above: Tamron 35-100mm f2.8 Di III at 70mm f5.6; crops also available at f8.0

Tamron 35-100mm f2.8 Di III at 100mm

Above: Tamron 35-100mm f2.8 Di III at 100mm f2.8; click image for 4k version, here for large original

Above: Tamron 35-100mm f2.8 Di III at 100mm f4.0

Above: Tamron 35-100mm f2.8 Di III at 100mm f5.6; crops also available at f8.0

Summary:

In this long-distance test the Tamron 35-100mm f2.8 Di III produced similar results to the Siemens-star test: The lens is very sharp across the full frame at the short end but profits a bit from stopping down at 70mm and 100mm focal length – although the FF/FX-corner seems to hold on pretty well over the entire zoom range.

Vignetting and distortions

To make it easier to see light fall-off in the corners of a full-frame sensor I’ve arranged a series of three shots each with the Tamron 35-100mm f2.8 Di III at 35mm and 100mm focal length and different apertures. All images were developed from RAW to the same brightness in the center and are shown with vignetting correction from the lens profile Off (1st row) or Normal/100% (2nd row):

Above: Tamron 35-100mm f2.8 Di III at 35mm focal length with vignette correction Off (top) or Normal/100% (bottom)

Above: Tamron 35-100mm f2.8 Di III at 100mm focal length with vignette correction Off (top) or Normal/100% (bottom)

At both focal lengths vignetting is very visible at around -2.4 EV when left uncorrected. With vignette control set to Normal/100% the extreme corners are lifted by around +0.9 EV at f2.8 – which still leaves a visible vignette.

Handling of lens profiles by Adobe’s Lightroom Classic V15.3 and RAW converter V18.3 continues to be confusing. Set vignetting and distortion control in camera to On and the Tamron 35-100mm f2.8 Di III gets its lens profile applied but you can change the strength of the correction in post-processing with sliders between 0 and 200%: Very good! But if you switch vignetting control in camera to Off the slider to control the strength of vignetting in Lightroom or CRAW is disabled. While if you switch distortion control in camera to Off Lightroom/CRAW simply ignore this and the slider is still enabled and set to 100%. NX Studio always applies what was set in camera but you can switch vignetting and distortion control On or Off (unless you have a lens which does not allow auto distortion control to be switched Off). So it’s better to leave the lens profile in camera On which enables all options when processing the image in Lightroom/CRAW.

Distortions are of a slightly mustachioed barrel type at 35mm and a strong pin-cushion type at the long end (see below). The lens profile corrects them well in camera or postprocessing. See the following composite images showing the upper part of two images shot as RAW:

Distortions: Tamron 35-100mm f2.8 Di III at 35mm, as is (top) / with lens-profile at 100% (bottom); click image for 4k version

Distortions: Tamron 35-100mm f2.8 Di III at 100mm, as is (top) / with lens-profile at 100% (bottom); click image for 4k version

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 colour-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 FX-corner of the Tamron 35-100mm f2.8 Di III at 35mm focal length and different apertures:

Above: Tamron 35-100mm f2.8 Di III at 35mm, f2.8; click image for 4k version, here for large original

Above: Tamron 35-100mm f2.8 Di III at 35mm; 100% crops from the FX-corner at f2.8 (left), f4.0 (middle), f5.6 (right)

The Tamron 35-100mm f2.8 Di III shows very little coma at 35mm.

Bokeh quality

This test is for the rendering of point-light sources in an out-of-focus background. The circle of confusion that is produced by the 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. 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.

Above: Tamron 35-100mm f2.8 Di III at 100mm, f2.8; click image for 4k version, here for large original

Above: Tamron 35-100mm f2.8 Di III at 100mm f2.8; click image for 100% crops

Above: Tamron 35-100mm f2.8 Di III at 100mm f4.0; click image for 100% crops

Above: Tamron 35-100mm f2.8 Di III at 100mm f5.6; click image for 100% crops

Above: Tamron 35-100mm f2.8 Di III at 100mm f8.0; click image for 100% crops

The Tamron 35-100mm f2.8 Di III shows a normal amount of compression of the circle in the DX- and FX-corner wide open. This is quickly reduced by stopping down and practically gone at f5.6. Bokeh balls stay well rounded even down to f8 – an indicator that sun-stars (diffraction spikes) will only become prominent when the lens is stepped even further down. There is a bit of outlining albeit almost free of coloration from loCA. The inside of the Bokeh balls shows some textures and weak onion rings.

Let’s see how this analysis of out-of-focus point-light sources translates into Bokeh-performance shooting a book-shelf. Crops are from the foreground, middle-ground, and background resized to make them comparable across all my reviews.

Above: Tamron 35-100mm f2.8 Di III at 100mm f2.8; click image for 4k version, here for large original

Above: Tamron 35-100mm f2.8 Di III at 100mm f2.8; click image for 100% crops, here for large original

Above: Tamron 28-75mm f2.8 Di III G2 at 75mm, f2.8; click image for 100% crops, here for large original

Above: Nikon Z 24-120mm f4 S at 120mm, f4.0; click image for 100% crops, here for large original

In the middle-ground and background the Tamron 35-100mm f2.8 Di III produces the smoothest Bokeh, clearly facilitated by the largest entrance pupil of the three lenses in this comparison. In the (less important) foreground the Tamron 28-75mm f2.8 Di III G2 has a slight advantage.

Looking at the ruler (below, now at 100%) shows that the Tamron 35-100mm f2.8 Di III produces some double-contours in the transition zone. The 28-75mm f2.8 Di III G2 is slightly better in this respect:

Above: Tamron 35-100mm f2.8 Di III at 100mm f2.8, 100% crop from middle-ground

Above: Tamron 28-75mm f2.8 Di III G2 at 75mm f2.8, 100% crop from middle-ground

Above: Nikon Z 24-120mm f4 S at 120mm, f4.0, 100% crop from middle-ground

For some real-life examples look at the grass and the trees in the background at 35mm f2.8 and 100mm f2.8.

Close-up performance

The Tamron 35-100mm f2.8 Di III achieves a maximum magnification of 1:3.1 at 35mm focal length with an area of sharp focus of 74 x 112mm. The following set of crops was shot at 1:3.6 from 0mm, 7mm, and 20mm off the center of the sensor respectively. I focused separately for each crop to avoid the influence of field curvature which is pretty heavy at 35mm focal length and these short distances.

Tamron 35-100mm f2.8 Di III at 35mm, 1:3.5 magnification; 100% crops

Above: Tamron 35-100mm f2.8 Di III at 35mm f2.8

Above: Tamron 35-100mm f2.8 Di III at 35mm f5.6

Above: Tamron 35-100mm f2.8 Di III at 35mm f11

Wide open the lens produces a pretty sharp center (up to 5mm image height). But to get good sharpness towards the DX-corners you need to stop down to f11.

At 100mm focal length the lens achieves a maximum magnification of 1:5.3 with an area of sharp focus of 127 x 191mm. The following set of crops was shot at 1:5.6 from 0mm, 10mm, and 20mm off the center of the sensor respectively. I focused separately for each crop to avoid the influence of field curvature.

Tamron 35-100mm f2.8 Di III at 100mm, 1:5.6 magnification; 100% crops

Above: Tamron 35-100mm f2.8 Di III at 100mm f2.8

Above: Tamron 35-100mm f2.8 Di III at 100mm f4.0

Above: Tamron 35-100mm f2.8 Di III at 100mm f5.6

The results are in general sharper than from shooting at 35mm focal length. Wide open the lens produces a pretty sharp center (up to 7mm image height). To get good sharpness towards the DX-corners better stop down to f5.6 at least.

Flare, ghosting, and sun-stars

Catching a strong light-source shining directly into the lens is always a risky business: 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 Tamron 35-100mm f2.8 Di III for these artifacts I went through a series of well calculated shots against a strong light source to provoke glare and ghosting. The lens hood was mounted in all shots. Following are two more extreme examples. The little red square inset in the upper left shows the respective area with an exposure compensation of +3 EV to make it easier to see which levels of black the lens renders at that point:

Above: Flare and ghosting. Strong light hitting the Tamron 35-100mm f2.8 Di III at 35mm, f11; click image for 4k version or here for +3 EV exposure compensation

Above: Flare and ghosting. Strong light hitting the Tamron 35-100mm f2.8 Di III at 100mm, f11; click image for 4k version or here for +3 EV exposure compensation

At the short end the Tamron 35-100mm f2.8 Di III produces some ghosting artifacts but little veiling glare: The blacks outside these artifacts stay deep black. And there’s also no flare which is typical for some lenses when the light-source is just around the FF/FX-corner – neither at the short nor the long end. Zooming in does produce stronger effects and also increases veiling glare.

At 35mm f11 the lens renders very nice sunstars with 18 diffraction spikes (see above). But up to f8.0 sunstars are not very prominent due to the well rounded aperture blades:

Above: Sunstars from the Tamron 35-100mm f2.8 Di III at 35mm, f4.0, f5.6, f8.0; 100% crops

Next check out my sample images!

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