What should I expect from Canon EF 24-70mm f/2.8L II USM?

Hey guys,

I'm a noobie around here so I hope I don't annoy too many of you with this question.

At the moment I have a Canon EOS 80D and the Canon EF-S 18-135mm f/3.5-5.6 IS USM Lens. I mostly use the camera for travel and street photography so I thought I should probably get a better zoom lens that would also allow me to move to a full frame in the future. So I decided that I'll go for a 24-70mm f2.8. (I know, perhaps not the best focal length on a cropped sensor for what I want) Between Canon, Sigma and Tamron people seem to praise Canon a lot so I decided to ake a big investment in the Canon EF 24-70mm f/2.8L II USM.

I've only had it for a short time, so I can't say I've tested it comprehensively, but I must say that so far I'm not impressed. Given that people (our of which many are professional photographers) are so happy with the lens, that must only mean I'm doing something wrong.

  1. What should my expectations be from Canon EF 24-70mm f/2.8L II USM compared to my existing EF-S 18-135mm f/3.5-5.6 IS USM? I realise that the price - image quality it's an exponential relationship, I was thinking that between two side by side photos I could pick the one L lens took in a heartbeat which is not always the case. (I also realise that L lens brings it other things which won't necesarily improve image quality like weather sealing and wider aperture)

  2. Given that the differences are not that noticeable, would it be worth for me to get instead the Tamron or Sigma which are cheaper, have IS and are still very good lens?

Later edit: Here are some samples (in Canon RAW).

  1. 24mm, 1/20s, f/9.0, ISO 100

    • from Canon EF 24-70mm f/2.8L II USM here

    • from Canon EF-S 18-135mm f/3.5-5.6 IS USM here

  2. 24mm, 1/60s, f/5.6, ISO 100

    • from Canon EF 24-70mm f/2.8L II USM here

    • from Canon EF-S 18-135mm f/3.5-5.6 IS USM here

enter image description here This is a crop from the f/5.6 sample at 200% zoom. Yes, there is some chromatic aberration and more distortion and maybe not as sharp image quality but is this the difference I should expected between a very expensive pro lens (right) vs a kit lens (left)?

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    \$\begingroup\$ You don't say why you aren't happy with the 24-70. \$\endgroup\$
    – AthomSfere
    Commented Apr 17, 2018 at 11:49
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    \$\begingroup\$ I think this is a good question that could help a lot of people...but do come back with more info. \$\endgroup\$
    – osullic
    Commented Apr 17, 2018 at 12:37
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    \$\begingroup\$ It's not the size of the lens, it's how you use it! \$\endgroup\$ Commented Apr 17, 2018 at 12:39
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    \$\begingroup\$ "my expectations were that by using a pro grade lens the photo quality would dramatically improve" - yes please do provide examples. Unless you're shooting in some very specific contexts, I'd not expect you to be lacking anything in your current lens (assuming your experience given your question) except a wider aperture. \$\endgroup\$
    – wally
    Commented Apr 17, 2018 at 15:50
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    \$\begingroup\$ Can I make a suggestion if you do another shot tomorrow... shoot at a faster shutter speed... you may notice a difference ;) \$\endgroup\$
    – Crazy Dino
    Commented Apr 17, 2018 at 22:03

3 Answers 3


The difference in technical quality between the two sample images is striking! Particularly the difference with regard to chromatic aberration. How much of the rest of it is attributable to the different lenses, however, is debatable. If you were shooting handheld, the differences in "sharpness" could be due to more camera motion in one shot than the other.

The problem is that too many new photographers think that buying a new lens with measurably better technical performance¹ will also improve their shooting technique, compositional vision, and lighting skills. It won't. At all.²

It just means they'll get sharper images with less chromatic aberration of the same poorly composed, badly lit, boring photos they were taking before.

If they are shooting handheld using less than stellar technique, the non-stabilized EF 24-70mm f/2.8 L II could actually give them blurrier photos than the EF-S 18-135mm f/3.5-5.6 IS.

Shooting handheld at 1/60, this is apparently what happened here. The IS of the cheaper lens prevented mild camera movement from blurring the photo. or maybe the camera didn't move at all when the cheaper lens was used. The sharper lens without IS is blurry because camera movement that occurred during that shot was not counteracted. It's not because the lens is less sharp. When you zoom in to a piece of an image that is 1/10 the width of the full image shot with a 24mm lens, it's the same as if you'd used a 240mm lens in terms of blur per image width for a specific amount of camera movement. The 1/FL*CF (focal length x crop factor) rule of thumb says shooting hand held on a crop body at 240mm magnification without IS one should use an exposure time of 1/400 or shorter if the full image is to be viewed at 8x10 or 8x12 inches. Your exposure time is over 6X longer than the recommended Tv.

I'll make a sort of confession. I have an original EF 24-70mm f/2.8 L. It's nowhere near as sharp as the EF 24-70mm f/2.8 L II. In fact, it is not even as sharp as the Tamron SP 24-70mm f/2.8 Di VC. It is sharper than the EF 24-105mm f/4 L IS when both are on a very stable mount. I rarely use the 24-70/2.8 instead of the 24-105/4 IS unless the camera is going to be on a tripod. Why? It's a sharper lens with a wider maximum aperture. Why would I possibly choose the less sharp f/4 lens, even when shooting in low light? Because as I age my ability to hold the camera perfectly still is not what it once was. I'm still pretty good, and can still do better than most novices one-third my age. But I'm not as good as I once was. And I'm not as good as I need to be to shoot at 70mm and 1/30 or 1/15 second at f/2.8 with an unstabilized lens versus shooting at 70mm and 1/15 or 1/8 second at f/4 with a stabilized lens. If the subjects are moving in that kind of light, it's way past time to get out the fast primes and put the zooms away.

A better lens will usually give better acutance and less aberrations. But a better lens won't somehow magically cause the light to be transformed or the colors to balance themselves better and "pop" off the screen/page. That's the job of the photographer, not the lens.

¹ Technical performance of lenses measured in a lab is normally done with the camera mounted on a very sturdy tripod, the lens precisely focused manually, and the shutter released remotely. Often, mirror lockup is also used, even though excellent lighting, including very short duration flash, is used to allow shorter exposure times.

² IS/IBIS can make up, to one degree or another, for poor camera stabilization technique. But it does not actually improve the photographer's technique, it only hides, to one degree or another, the photographer's lack of better technique.

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    \$\begingroup\$ Love the last paragraph! \$\endgroup\$
    – Crazy Dino
    Commented Apr 17, 2018 at 22:10
  • \$\begingroup\$ I know I've got a long way to go on my composition and lighting skills and I definitely didn't expect the lens to help with that. :)But what I was expecting was that for the same composition (be it good or bad) the difference in image quality would be more noticeable. \$\endgroup\$
    – Damian
    Commented Apr 17, 2018 at 22:45
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    \$\begingroup\$ The difference of your example is rather noticeable in terms of lens performance. It's huge! \$\endgroup\$
    – Michael C
    Commented Apr 17, 2018 at 22:46

Mounting a full-frame lens on an APS-C body probably won't yield you the results that you were expecting.

Have a quick look between the lens on a 70D vs same lens on a 5D Mark IV and there's a difference in sharpness. Both cameras side-by side on the same charts.

Don't feel that I'm telling you to upgrade the body. Because I'm not.

How did you get your hands on the 24-70? Did you rent it? or did you buy it? If you rented it, maybe try something a lot more suited to your camera. If you bought it, and you're thinking of selling it, you could end up taking a loss, so think carefully about that.

If you're set on switching out the lens, factor in the weight and bulk. You say you'd like to do street and travel photography. I'd imagine lugging that 800g of a lens gets old rather quickly. A 35mm prime or 50mm prime would get you similar results for lighter weight, and probably cheaper.

Image quality isn't everything - I've got plenty of photos that are technically good but rather soulless sitting on my hard drive.

I'd probably just go out there and shoot more. If there's a way for you to recoup without taking massive losses, then sure. Otherwise, It's a lens. Use it :)

  • \$\begingroup\$ Even two different FF cameras of significantly different resolutions will affect the "Sharpness" results at DxO. The FF 22MP 5DIII is closer to the APS-C 20MP 70D than the FF 51MP 5Ds R: dxomark.com/Lenses/Compare/Side-by-side/… \$\endgroup\$
    – Michael C
    Commented Apr 17, 2018 at 22:15

What should I expect from Canon EF 24-70mm f/2.8L II USM?

Less than you're led to believe from online forums, where everyone discusses this stuff like it's life and death and where L lenses are praised as miracle-workers. Disappointment with a first L lens for a Canon hobbyist shooter is almost guaranteed. Everyone goes through it.

Most newbs will have the expectation that the improvement in a lens they'll see will be proportionate to the cost increase of that lens. But in photography, as with most things in life, higher-end stuff tends to be a game of diminishing returns. While you may be paying 2x or 3x as much for an L, you may only be getting a 10-20% improvement. You may get much more, but it may also have nothing to do with sharpness.

Also understand there is a certain psychology at work in online discussion fora about photography gear. A lot of folks may be feeling just a wee bit guilty about spending so much on gear, and will therefore identify and argue more vehemently about its superiority to prove they were justified in spending that much.

Or. They're pros whose business profits allow them to write the lens off on their taxes as a business expense, so the cost isn't that high to them, and the 10% improvement shaves off a ton of post-processing time, which makes them more profitable while putting in fewer hours. Consider who's reviewing the lens and what their POV is. It could be quite different from yours.

With your first L lens, as a Canon hobbyist shooter, buyer's remorse is likely to bite really really hard, when you find out that it's not magic, it doesn't instantly render all your images gorgeous, it's bigger/heavier/more inconvenient, a lot more expensive, and only marginally nicer than what you had. It'll take a while to fall in love with its true charms: the f/2.8 max. aperture, the more optimized performance across the range, the better CA control and the higher contrast you can sometimes get with L glass. And you won't see the corner performance or the better vignetting control until you plop it on a full-frame body. You may not fall in love with it at all.

And, of course, you're still a beginner, so you may not realize what's down to the lens, and what's down to your lack of technique/knowledge. For example, with your test crops, your shutter speeds are easily slow enough to register camera shake blur. Particularly if you don't have good handholding technique.

This is a crop from the f/5.6 sample at 200% zoom.

And then there's the pixel-peeping. Judging an image at 200% zoom is like making a poster-sized print and looking at it from about two inches away. It's not a particularly realistic way of looking at things, though every digital shooter does do it. But you might want to consider printing an image every now and then and hanging it on a wall.


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