A lot of good rumors about the Sigma 50mm Art that was announced for the end of April. I have decided to order one as soon as it was available here in Belgium, and I wanted to do a comparison between this praised newcomer and the 50 mm f1.4 I have been using since about two years. (see battle of the 50’s for a comparison between Canon’s cheap (fantastic plastic) 50 mm f1.8 and the second in line 50mm f1.4 from Canon as well)

So this time a comparison between the Sigma 50mm f1.4 DG HSM Art and the Canon EF 50 mm f1.4 USM.

Both aimed at the full frame market, a rather old design for the Canon, brand new for the Sigma, part of the ‘Art’ series of new lenses from the latter.

In my photography I often have to deal with difficult light situations (I mostly work with natural light only) in dim lit interiors. I so have decided a couple of years ago to mainly go with fixed focal length lenses with big apertures. I currently have a Canon 24 mm f1.4 L II, a 50 mm f 1.4 (Canon and Sigma, although the Canon has already been sold and will be transferred to its new owner as soon as this test is over) a Canon 85 mm f1.8, a Canon 100 mm f2:8 macro (NEW) and a Canon 135 mm f2.0 L. A lot of glass and a lot of weight in my photo bag.

Additional weight for this 50 mm lens from Sigma too, compared to the Canon f1.4 (290 g) the Sigma comes at 815 grammes, meaning a lot more weight to carry. In combination with the Canon 5D mark II I use, this combo weighs about 1700 grams all together. My wife complained about the weight when I had her review the images of my last shoot.

The design of the Sigma lens is definitely more attractive, with is matte finish and sleek all black no colors approach. It comes with a hood and caps, and a square semi-hard lens case. The price here in Belgium is 839 € (Art & Craft pre-order) while the Canon comes at 339 € at the same shop.

All images for this test have been taken in my backyard or home studio, no special things going on here, except for young vegetable sprouts struggling against the spring rains we had lately.

As far as needed, all images are taken with tripod, live view magnification for focussing and with the same 5D II camera. Self timer to prevent touch shake.

The images show the entire scene on top, 100% crops from unedited images (except standard sharpening in LR5) below. The aperture setting is mentioned on every crop. All Jpg’s are saved at 100% quality. Take care, some of these images are big! All these images are for informational purpose only, no legal claims made!

You should really look at the images full size to be able to judge on the results obtained!

Sharpness center and edge:

Left to right: Canon center sharpness, Sigma center sharpness, Canon edge sharpness, Sigma edge sharpness.

Full size on click, 11.9 Mb Jpg file.

My observations:

Center sharpness Canon: soft wide open, reaches full sharpness at f2.8, stays sharp till f8.0, a little diffraction softening at f16

Center sharpness Sigma: similar sharpness wide open as the Canon at f2.8, small increments of additional sharpness till f8.0, clearly visible diffraction effects at f16

Edge sharpness Canon: strong image distortions in this part of the image at f1.4 and f1.8, as if the image has had a rotational blur, gradually improving image quality, acceptably sharp at f8.0, soft degradation at f16

Edge sharpness Sigma: similarly sharp at f1.4 as the Canon at f1.8, but no distortions, f4.0 similar to Canon at f8.0 and sharpest at f8.0 and better image detail as the Canon at f8.0. More diffraction degradation at f16 than Canon.

Note the strong vignetting on the Canon f1.4 USM when used wide open. Less visible on the Sigma.

Vignetting is becoming invisible at f4.0 for the Canon, at f2.8 for Sigma.

Minimal focussing distance. Sharpness and magnification:

the minimal focus distance for the Canon is 0.45 m, for the Sigma it is at 0.4 m, so a bigger magnification is possible.

Another set of images, both showing the magnification comparison, and a crop showing sharpness with different apertures.

my observations:

similar as previous test, very weak performance at the image edge for Canon, at least one stop better sharpness for the Sigma in both center and edge.

The Sigma lens has however more problems with purple fringing when used wide open (note the hairs on the plant stem). This reminds me of the ‘quick’n dirty 85mm lens test’ I did a couple of years ago, where similar fringing problems where appearing with the Sigma 85 mm f1.4

Chromatic Aberration and color fringe:

I remember from the previous test that the Canon proved horrible in the shots with the branches agains bright background. Let’s see what the Sigma does in comparison. I had no clear sky as the previous time today, but I kind of see the same things happening here.

The Canon f1.4 USM suffers from severe fringing in high contrast areas, when used wide open. (strange that this phenomenon did not show in the plant close up) This is even apparent in live view, making it hard to focus correctly. When stopping down to 2.0, this greatly improves, and then we see similar things in both lenses, the Sigma not noticeably performing better in this aspect, showing purple fringing in front of the focus area, green fringing behind the focus plane.

In both examples in this test however (overcast sky, dull weather) I have noticed very little CA in both lenses, a little bit of cyan-orange at f8.0 in the Canon image close to none in the Sigma. I suppose that in higher contrast situations, that might be worse. (to be confirmed).

Worth noticing in this respect is that the Sigma 50mm Art lens profile is not yet currently available in the standard Lightroom 5.4 upgrade, nor could I find a link to a profile for this lens on the web (may 13, 2014)

Longitudinal CA:

Chromatic aberration that is visible in the unsharp areas in front and behind the sharp area. Not the magenta shift in front of the sharp area, the green shift behind. Both images taken at f2.0. Remarkably higher in the Canon. Note the big difference in sharpness and contrast in the sharp areas between the two of them. Best viewed at 100% of course.

Flare:

Canon to the left, Sigma to the right.

My observations: Do I really need to? It’s obvious I guess.

Bokeh:

Canon to the left, Sigma to the right. I think Sigma’s bokeh is softer and smoother. In the Canon unsharpness, there is still some structure and noise. Not 1/1 images but big enough to analyze.

Thank you for reading, I think I will keep my Sigma, and trade on the Canon.

You are welcome to share this comparative review, I take no responsibilities of any kind 😉

come back again for some real world image samples of this lens in my shoots!

best,

Ludwig