Sigma 24-35mm f2.0 DG HSM Art Lens Review

The non-photographers amongst you might want to skip this blog posting as this is a fairly detailed Sigma 24-35mm F2.0 DG HSM Art lens review, comparing it to Sigma’s 24mm and 35mm f1.4 prime Art lenses. This is primarily written for other wedding photographers who may be interested in whether this zoom lens is the right choice for them instead of a pair of fixed focal length primes.

I’ve been a massive fan of the Sigma 35mm f/1.4 DG HSM Art prime lens since I first got hold of one over two years ago. At weddings it’s rarely been off my camera as it focuses fast and is as sharp as a tack . . .

I normally shoot with a 35mm / 85mm dual camera setup and the only time the 35mm tends to come off is for dance floor action or when I need something a little wider due to space limitations. It’s then that I reach for the Sigma 24mm f/1.4 DG HSM Art . . .

The one problem I have with this is that I like to work quick at weddings. I sometimes feel I could be missing moments swapping lenses and it’s a bit of a pain carrying other gear about. Plus I’m a bit clumsy at the best of times, so I have a perpetual fear of dropping a lens and de-centering it . . . or worse. Some people could argue why don’t I leave the 24mm on all the time and avoid swapping lenses? The main problem I have with doing that is that the 24mm has more noticeable distortion and the focal length means that sometimes you have to get in a bit too close to frame a shot. Hence why I prefer to shoot mainly with the 35mm and only switch out to the 24mm when it’s really needed.

Back in 2015 Sigma created a bit of a stir when they launched the 24-35mm F2.0 DG HSM Art zoom lens. This was a world first – a full frame zoom lens with a constant f2.0 aperture, full frame zooms are usually limited to a maximum aperture of f2.8. A lot of people asked questions as to whether there was really any need for this lens. Yes it has an f2.0 aperture but it has such a short zoom range, is it really necessary? However; for many wedding and event photographers it sounded ideal. I hardly ever shoot with the aperture of my primes wider than f2.0 so could this be the answer to my 24mm / 35mm lens swapping anxiety? I’ve been curious about the lens for a long time and when I recently saw a barely used one come up at a reasonable price I thought I’d give it a go and put it through its paces.

Sharpness

A lot of people online have been saying that the 24-35mm f2.0 zoom is as sharp as a prime lens. Being as I also have the Sigma 24mm and 35mm primes the first thing I did was put it to the test and find out. For this test I used a Canon 5D mkiii and ran the same camera body with each lens attached through a micro adjustment test using Reikan’s Focal software. Once each lens was adjusted for maximum sharpness I then ran Focal’s aperture sharpness test to enable a comparison to be made on all the lenses across their aperture range. The zoom lens was tested at both ends of its reach to allow comparisons with the prime 24mm and 35m lenses. Each test was performed twice to ensure repeatability of results. I’ve overlaid the full results in the chart below, the results at 24mm are in red and 35mm in green. The zoom lens is represented by the solid line and the primes by the dashed line. Aperture is on the horizontal axis with the Focal quality measure score on the vertical.

What we can see from this is that across the entire aperture range the zoom is sharper at the 24mm end than the 35mm end. With the primes the 35mm is sharper at wide open apertures but the 24mm is sharper stopped down. Plotting the data a little differently, using the difference between the zoom and the prime results rather than absolute value, gives a slightly clearer picture of the difference in performance between the lenses. Again I have used red for the 24mm results and green for the 35mm. Where the trace is above the zero line it means the zoom is better than the prime and below the line shows the prime is better.

Looking at the data we can see that the zoom lens is indeed a match for the two prime lenses. At 24mm the zoom looks a little better, whilst at 35mm a little worse. Over the full aperture range the zoom and prime lenses are within 10% of each other. I’m going to stick my neck on the line and say that under normal shooting conditions you will not see any difference between the lenses. If you’re a pixel peeper, you might notice a tiny difference in some shots when zoomed in at 1:1 or greater . . . but hey, normal people don’t pixel peep!

Now there is a big caveat around this set of test results. I have one copy of each lens and I don’t know if the copy I have is a good one or not. Fortunately, Focal again comes to our help as the aperture sharpness test shows data from other users lenses. Here’s an example plot of the results from my Sigma 35mm f1.4 Art lens . . .

If the trace is in the red area it means that the lens under test is performing below average compared to the Focal test database when fitted to the camera body you are using (in this instance the Canon 5D mkiii). The purple area is the average performance band and the green area is above average. I see from the above chart that my 35mm f1.4 is mainly above average (or towards the top end of the average band) between f1.4 to f7.1. I’ve not included the plot from my 24mm lens but the results show it is below average in the f2.0 to f5.6 range. I think this could go some of the way to explaining why the zoom appears better than the prime at 24mm but worse at 35mm. Unfortunately Focal did not show the average data for the 24-35mm zoom on the Canon 5D mkiii, this is probably due to Reikan not having a sufficient pool of data on the lens when I did the test.

Image Quality

It’s not just about sharpness though, there are many other factors that contribute towards image quality; bokeh and colour rendition being two of the most important things for me. To test these I shot the same scene with all 3 lenses mounted to the same camera body, again using my Canon 5D mkiii. For my subject I used the very patient Penny the Penguin, she’s really good at standing still, ensuring that the scene would be the same between shots. The camera was mounted on a tripod and set to manual mode with the following settings: ISO 100, f2.0, 1/400s. When switching from the 24mm to 35mm focal length the camera position was altered to keep Penny approximately the same size in the frame. The images were all shot in RAW format and imported into Adobe Lightroom with no other corrections being applied other than to white balance on the same spot in each picture (I’d accidentally left the camera in AWB mode!).

First, a look at the files from the 24mm prime and the zoom set a 24mm, both lenses set to f2.0. I’ve overlaid the images as a GIF file to make the comparison easier.

The first thing that is noticeable is that the field of view is ever so slightly different between the lenses, with the zoom lens having a slightly wider field of view than the prime.  It should be noted that the camera position does not move between the two shots, only the lens is changed. There is also a marked difference in the distortion and vignetting with both being more pronounced on the zoom. These two effects are expected as the zoom is a much more complex optical design and was also being used wide open, where the prime had already been shut down by one stop.

Here’s the same images but with the lens corrections applied in Lightroom to fix the distortion and vignetting . . .

Lightroom does a great job here but you can still see the slight difference in the field of view. The next image is the same scene but this time with the 35mm prime and the zoom at 35mm, again both lenses at f2.0. The camera position has been moved from the 24mm shot to keep Penny the Penguin roughly the same size in the frame.

We see similar issues again with slight difference in the field of view and more vignetting and distortion on the zoom.

And again with the lens corrections applied in Lightroom . . .

This time I’d say the difference in the field of view is less pronounced, although the zoom is again a little wider than the prime. Comparing the colours in the pictures above I can’t see any significant difference in the colour output of either lens, although the zoom lens does appear just a tiny bit brighter.

Bokeh

How the lens renders the out of focus areas is also really important. The in focus areas need to be sharp with smooth out of focus areas desireable in order to give nice separation of the subject from the background. I want the bokeh to be as free from detail as possible so that the eye is drawn to the subject. What’s noticeable from the images above is that the out of focus areas do not appear quite as smooth with the zoom lens, showing a little more detail. The GIF image below is a crop from the far left hand side of the frame on the 24mm Lightroom corrected images . . .

I’ve not included the crop from the 35mm lens but the issue still visible with more detail being present in the bokeh of the zoom lens than the prime. I’m not sure why this should be the case as all three lenses are listed as having a circular aperture with a 9 bladed design, could this be due to the more complex optical design of the zoom lens?

Focus Speed

Another of the key performance characteristics for me is the focus speed, it’s no good having an optically great lens if it takes too long to obtain sharp focus. This is especially important for documentary / reportage photographers who are trying to capture moments as they really happen rather than setting things up. For this test I set the 24-35mm zoom to 35mm and compared it to the 35mm prime. Each lens was in turn mounted to my 5D mkiii, set to f2.0 and manually set to its minimum focus distance. I then lined up the centre focus point to a high contrast object that was at infinity and half pressed the camera shutter button using AF to lock focus. Whilst this was being done I pressed a microphone right up against the lens barrel and recorded the sound using the start of the focus confirmation beep as the timing end point. I then imported the files into Audacity and trimmed them so that all of the extraneous dead time was removed from the recordings. The results are shown in the picture below. The zoom lens at 35mm is the top trace and the 35mm prime is the bottom trace, the two high amplitude pulses at the end of the trace are the focus confirmation beep.

We can see from this that the zoom focused in 0.585s and the prime in 0.61s. I was completely surprised by this result and repeated the test two more times to make sure that I hadn’t done anything wrong. I had assumed that the zoom would be slower as it has a shorter minimum focus distance of 0.28m v 0.3m for the prime. I’d also assumed that the focusing group would be more complex and heavier in the zoom which would also lead to a slower focusing time. Again, in real world terms the difference is marginal, both lenses are within 4% of each other and would not expect this to have any noticeable impact on usability in the real world.

Weight

The biggest disadvantage that the zoom lens has over the primes is its weight. The 24-35mm zoom weighs in at 941g, where each of the Sigma primes are 665g. The weight isn’t excessive, it’s not like carrying a 70-200 f2.8, which tips the scales at 1490g, but it does make it noticeably heavier than either of the prime lenses when in the hand. It’s a similar weight to the Canon EF 24-70mm f/2.8L USM, which tips the scales at 950g. The only time I really noticed the extra heft was when shooting dance floor shots holding the camera high in one hand. Other than that the extra weight didn’t really bother me. The other way of looking at is though is that your total kit weight is less, as you now only need one lens, but the on camera weight is more.

Size

As well as being heavier the zoom is also longer than both of the prime lenses. The 24-35mm zoom has a length of 121.9mm, where the 24mm prime is 90.2mm in length and the 35mm prime 94mm. What is nice is that the mechanism on the zoom lens is fully internal so the length does not change, this helps to give it a more solid feel than most zooms which have extending front elements. Here’s a photo comparison of the 24-35mm zoom and 35m prime.

It’s not just the length that is increased on the zoom as the barrel diameter is also larger resulting in a bigger filter size. I always protect my lenses with a clear filter in front of the front element, but the 24-35mm f2.0 is whopping 82mm in diameter. This will add significant cost compared to the 77mm diameter filter thread on the 24mm prime and the 67mm filter on the 35mm lens.

Build Quality

When the Sigma Art lens range was released it was roundly praised for bringing top quality optics at a fraction of the price of native Canon or Nikon lenses. Although I really love my 35mm Art lens it has started to show a fairly significant build quality issue where the mount end of the lens is coming lose. You can see an example of this in the following video -> Sigma 35mm 1.4 ART lens repair. If this happened at a wedding it could have fairly dramatic impact on your pictures, potentially resulting in out of focus images. It’s a fairly simple fix but I wouldn’t expect something like this to happen on what is being marketed as a high quality lens. I will have to reserve judgement on any build quality issues with the 24-35mm zoom as the problem with the 35mm prime took well over a year to first appear. However; as noted above , it does feel solid. I also know of quite a few other wedding photographers who have focus problems with the Sigma Art 35mm where it will back focus as the focus moves closer to infinity. I’ve not noticed this problem with my copy but I’ve seen enough people talking about this to know it can be an issue.

Flare

The Sigma 24mm isn’t free of issues either. I’ve noticed that it’s fairly prone to flare when shooting backlit, resulting in large circular rainbow reflections around the periphery of the image. I have several shots that have been unusable due to flare with the 24mm. It can look kind of cool sometimes though . . .

I’ve only shot a handful of weddings with the 24-35mm zoom so far and never managed to generate any significant flare at any focal length so this looks like a big improvement over the 24mm. The following is the worst flare I’ve seen with the zoom with the sun full onto the edge of the frame.

Quirks

There are a couple of quirks that you need to be aware of if you’re using Sigma lenses. The first issue that applies to Canon users is that the zoom ring on Sigma lenses operates in the reverse direction compared to native Canon glass. This won’t be a problem for Nikon users but it does take a little getting used to. After using Canon cameras for as long as I’ve been shooting my muscle memory automatically twists the zoom ring anti-clockwise to zoom in.

Because Sigma lenses are third party equipment there is no onus on Canon to resolve any compatibility issues when new cameras are released or when firmware is updated on old cameras. Being as these are not native Canon lenses there are no lens correction algorithms built into the camera JPEG engine. It’s not really a problem for me as I shoot RAW and do most of my editing in Lightroom. However if you get the correction settings wrong in camera it can cause all sorts of fun as detailed in this article -> SIGMA ISSUES A LENS INCOMPATIBILITY WARNING FOR CANON 5D MARK IV & OTHER EOS CAMERAS.

Price

In terms of price the 24-35mm f2.0 zoom is listed as £949.99 although it’s currently on Amazon for £699.00, my barely used copy cost £500.00 which I consider to be a great value. The 24mm and 35mm f1.4 primes are both listed as £799.99, but is are available for £618.95 and £569.00 respectively on Amazon. I think the current pricing makes the zoom great value compared to buying the two primes.

Summary

So would I recommend this lens? If you’re like me and want to avoid 24mm to 35mm anxiety but still want a prime like aperture, then definitely yes. There are some areas where the zoom lens doesn’t quite match the performance of the prime equivalents and a couple where it outperforms them. However; in reality the differences in performance are so minor that they are not really noticeable in the real world. The disadvantage of the increased weight and size more than makes up for the convenience of not having to change lenses and still allows me to shoot at prime equivalent apertures of f2.0. It’s a big thumbs up from me and a tip of the hat to Sigma for doing something different and creating a unique lens.

Here’s a few more sample images from the Sigma 24-35mm f2.0 zoom . . .