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Specific image quality issues

As always, our studio tests are backed up by taking hundreds of photographs with the lens across a range of subjects, and examining them in detail. This allows us to confirm our studio observations, and identify any other issues which don't show up in the tests.

Flare

Many fast lenses have problems with flare when pointed at bright light sources - the sheer amount of glass makes suppression of internal reflections relatively difficult. With this in mind, the Tamron performs well when the sun is within the frame, giving barely any ghosting from internal reflections, or general loss of contrast from veiling flare. This is shown in the first example below.

This impressive resistance to flare persists when shooting into the light at the telephoto end of the zoom. In the second example, the sun just is outside the frame, above and to the left of the tree, and yet overall contrast is retained very well. Overall this is a pretty impressive performance.

Canon EOS 6D, 24mm, F22 Canon EOS 6D, 70mm, F11

Chromatic aberration

The studio tests suggest the 24-70mm has relatively low lateral chromatic aberration, and this is confirmed in real-world use. As usual, CA is at its worst at wideangle, but even then it's barely worth worrying about. On Canon SLRs (which can't correct CA from third-party lenses in their JPEG processing) you'll see a little red/cyan fringing around high-contrast edges in the extreme corners of the frame; Nikon SLRs, in contrast, will compensate for this automatically. Any competent modern Raw converter will correct CA pretty easily too.

In the examples below we're looking at colour fringing in the corners of the frame at 24mm. Here we're comparing an out-of-camera JPEG from the Canon EOS 6D with the corresponding Raw file converted using Adobe Camera Raw, with CA correction enabled. There's a little fringing in the JPEG, which is removed completely from the corrected Raw conversion.

Lateral Chromatic Aberration - Canon EOS 6D, 24mm F8
Camera JPEG Raw converted in ACR with CA correction
Camera JPEG, 100% crop 100% crop: fringing removed

Vignetting

The tests show that the 24-70mm F2.8 exhibits about 2 stops vignetting wide open at the each end of its range, but somewhat less in the middle, which is fairly typical for its class. At both 24mm and 70mm it gives quite abrupt vignetting in the extreme corners, which can be visually quite intrusive in some some situations. Naturally this can be corrected in post-processing using software such as Adobe Lightroom or DxO Optics Pro. But while most SLRs can correct vignetting when used with the manufacturer's own lenses, they won't with third party optics like the Tamron.

The rollover below shows images shot at F2.8 using the Canon EOS 6D, looking at RAW files converted in Adobe Camera Raw with and without vignetting correction enabled. At 24mm the uncorrected vignetting doesn't look too bad in isolation, although here it's accentuated when flicking back and forward with the corrected version. However at 70mm the vignetting is quite intrusive, and we suspect many users would prefer to tone it down a little in post-processing in this kind of shot. To be fair though, this isn't really any worse than the Canon EF 24-70mm f/2.8L II USM.

Canon EOS 6D, 24mm F2.8, uncorrected 24mm F2.8, corrected
Canon EOS 6D, 70mm F2.8, uncorrected 70mm F2.8, corrected

Distortion

The Tamron shows fairly strong barrel distortion at wideangle, which can be a problem with certain types of shot. This distortion is notably higher than its Canon and Nikon counterparts, and while it's also pretty strong compared to the Sigma and Sony 24-70mm F2.8s, they both exhibit complex 'moustache' distortion. The rollover below shows an instance where the Tamron's barrel distortion has resulted in a decidedly odd-looking picture out-of-camera, and the corrected version looks much better.

Canon EOS 6D, 24mm
Distortion uncorrected Distortion corrected in ACR

Background blur ('bokeh')

One genuinely desirable, but difficult to measure aspect of a lens's performance is the ability to deliver smoothly blurred out-of-focus regions when trying to isolate a subject from the background, generally when using a long focal length and/or a large aperture. The 24-70mm's fast maximum aperture means it can provide nicely-blurred backgrounds at the telephoto end.

The degree of blur isn't all that matters, of course, but also its aesthetic quality (which is what the word 'bokeh' refers to). This changes with focal length, aperture, focus distance and background distance, so isn't possible to pin down in simple terms. But after shooting hundreds of real world shots with the lens, we'd say the Tamron generally acquits itself well, delivering attractively-blurred backgrounds most of the time. A couple of examples at different focus distances are shown below.

EOS 650D, 70mm F2.8, close-up EOS 6D, 70mm F2.8
Background detail Background detail

In the first close-up shot, the Tamron does particularly well - the background is beautifully blurred, and the transition from the in-focus rose bud to the out-of-focus leaves smooth and attractive. These qualities tend to persist on stopping down, too. In the second example the distant background is a bit more 'busy', but it's far from unpleasant if you view the image as a whole.

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Comments

Total comments: 14
Neogene

Used during my 15days Japan Tour, after three days of rain the lens got steam inside it, i had to wait until it got dry.

It's a mess isn't weather sealed.

I noticed a bit of color aberrations during my cloudy shots.

0 upvotes
jkmnop

...still going:

When we talk about lens contrast, we are not talking about that quality. What we're talking about is the ability of the lens to differentiate between smaller and smaller details of more and more nearly similar tonal value. This is also referred to as “microcontrast.” The better contrast a lens has (and this has nothing to do with the light/­dark range or distribution of tones in the final print or slide) means its ability to take two small areas of slightly different luminance and distinguish the boundary of one from the other.

https://luminous-landscape.com/understanding-lens-contrast/

OK. Done.

0 upvotes
jkmnop

...still going:

*microcontrast/lens contrast - here's an interesting piece (predating the digital era) about what this means and what you're looking for/at when you're digging deeply into the quality of a lens. Here's the essence of the piece (by my lights):

Many photographers and even some experienced and knowledgeable ones, seem permanently confused about contrast, especially when the word is used to describe lenses. In photography, like the word “speed” (which can refer to the maximum aperture of a lens, the size of the gap in a constant-rate shutter, or the sensitivity of an emulsion), the word “contrast” actually refers to several different things. “Contrast” in photo paper, for instance, or in a finished image, refers to overall (sometimes called “global“) contrast, meaning how the materials distribute tonal gradation from black to white or lightest to darkest.

0 upvotes
jkmnop

...continued from previous post:

At 100mm - I compared the Tamron at 70mm and forgot to try the 70-200mm here - and here again the 24-105 was better on both counts. And, if you want to have your socks blown off for reasonable bucks, check out this 100mm: stunningly beautiful sharpness and contrast.

0 upvotes
jkmnop

So I went back and tested the Tamron SP 24-70mm F/2.8 Di VC USD vs all of the lenses I have:

Canon EF17-40mm F/4L USM
Canon EF50mm F/1.8 II
Canon EF24-105mm F/4L IS USM
Canon EF100mm F/2.8 Macro USM
Canon EF70-200mm F/4L IS USM II

Except in the case of the 100mm I matched focal lengths and shot everything at F4, the same image, from a tripod.

The 50mm lens, a cheapie but goodie, trailed the pack. Not worth discussing.

At 24mm the Tamron showed slightly less sharpness than the 17-40 and markedly less sharpness than the 24-105. Microcontrast/lens contrast* was noticeably poorer than both the Canon lenses resulting in flatter depth and flatter tonality.

At 50mm the Tamron showed slightly better sharpness than the 24-105 but again the microcontrast/lens contrast* was poorer resulting in poorer perceived sharpness away from the point of focus as well as flatter tonality.

At 70mm the 24-105 was sharper and showed better contrast. The 70-200 smoked them both...continued.

0 upvotes
jkmnop

Just bought one yesterday and will return it. I was hoping to replace my Canon EF2-105mm f.4L IS USM with it. I tested the Tamron against my existing lens as well as my Canon EF70-200mm f/4L IS2USM at the 70 mm focal length.

While the Tamron is good there is, on close inspection, a very noticeable difference in the differentiation of highlight and shadow between the Canon lenses and the Tamron. The Canon lenses do it much better. This improves perceived three dimensionality as well a giving a depth and richness of tone that the Tamron simply does not. The Tamron images appear flat and washed out compared to those with the Canon lenses. I'm all about that tone.

Sorry, Tamron. Keep swinging.

Comment edited 34 seconds after posting
0 upvotes
robogobo

I'd love to hear some real world anecdotes from someone who went from the Canon 24-70 v1 to the Tamron, instead of going with the Canon 24-70 v2. Any regrets? It's the Zoom ring location and backwards direction that are making me hesitate. I've been shooting with the Canon for 12 years and can't imagine relearning that reflex.

Also, I've heard a few stories about AF problems with the Tamron.

Never used a Tamron lens before. Always thought they were junk. I have used a few Sigmas and had mixed feelings, though their Art line is stellar.

0 upvotes
Average User

Will Tamron make this lens for Sony FE mount? If so, could it have image stabilization?

0 upvotes
Jimothy H

Hello Admin,

Why is it the quality decrease when step down from 2.8 to 4 at the 70mm end? It's for a crop sensor test. The test with full frame doesn't have the same problem.

0 upvotes
jungfrow

Hi,
Just bought the Tamron SP 24-70 Di VC USD for nikon.
I noticed that there is a plastic rubbing sound when it focuses and when moving around the elements inside the lens seem to bump around a bit.
Is that normal?

0 upvotes
Chamu

Just bought this recently and absolutely love this lens. The lens is sharp and very quick. It's a very good alternative to similar Nikkor lenses.

0 upvotes
Nader Erfani

Indeed a very good lens which thanks to its stabilisation offers a lot more towards creative photography than one would at first anticipate.

0 upvotes
ecube

This Tamron SP 24-70 f/2.8 seem a cheaper and better alternative to Nikkor 24-70mm f/2.8. I'll stop by a local dealer to try it on my D800

1 upvote
camerosity

Just got this lens today. It's amazing. Heavy! But sharp at f2.8 and beyond with my D800.

0 upvotes
Total comments: 14