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)?

  • 3
    You don't say why you aren't happy with the 24-70.
    – AthomSfere
    Apr 17, 2018 at 11:49
  • You tell us what your expectations are and why you dont think theyr'e being met? We can't answer that!
    – Crazy Dino
    Apr 17, 2018 at 12:28
  • Also what side by side comparisons have you done? Have you taken two identical photos, same focal length and aperture (say 50mm f/4 @ ISO-100) and looked at 100% crop of the focus points AND the corners?
    – Crazy Dino
    Apr 17, 2018 at 12:31
  • 1
    It's not the size of the lens, it's how you use it! Apr 17, 2018 at 12:39
  • 2
    "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.
    – wally
    Apr 17, 2018 at 15:50

2 Answers 2


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 performance will also improve their compositional and lighting skills. It won't. At all.

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.

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
    Love the last paragraph!
    – Crazy Dino
    Apr 17, 2018 at 22:10
  • 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.
    – Damian
    Apr 17, 2018 at 22:45
  • 1
    The difference of your example is rather noticeable in terms of lens performance. It's huge!
    – Michael C
    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 :)

  • 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/…
    – Michael C
    Apr 17, 2018 at 22:15

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