If you're looking for a great fixed-focal length portrait lens for a Canon APS-C camera, then you're looking for a bright lens with a focal length between 50 mm and 100 mm. The Sigma 50 mm 1.4 Art surprised us as the ultimate standard lens for Canon full-frame cameras, with an exceptionally high build quality and image quality. It is thus not really a surprise to discover that in this review the Sigma 50 mm 1.4 Art also landed on the top of the heap when tested on our Canon 650D test camera. On a Canon SLR camera with an APS-C sensor, this looks like a bright portrait lens, with a bokeh that gives nothing up to many portrait lenses on a camera with a full-frame sensor. In addition, it's also a perfect lens for concert photography, night photography and street photography.
Sigma 50 mm 1.4 Art on a Canon 650D: At full aperture, you simultaneously profit from high sharpness and a beautiful background blur. For a lens of f/1.4, the high sharpness at full aperture in particular is unique; usually bright lenses do not excel in sharpness at full aperture. The Sigma 50 mm f/1.4 does, just like the Sigma 35 mm f/1.4 Art and the Sigma 18-35 mm f/1.8 Art.
Build and auto focus
Dpreview: 'The best autofocus prince that we've ever reviewed.'
This lens is designed and built with the greatest possible care. The finish is of a professional level, built to last for a lifetime—unless you drop it in the water, because the lens is not extra-well sealed against moisture. The lens mount is made of a heavy metal alloy, in which there is no play at all. That is—with the sensor of the camera, the precision of the AF and the quality of the lens design determine the sharpness. Automatic focus occurs quickly and with precision. Our review model showed no front or back focus at all. With this lens and any camera, you won't have trouble with front focus or back focus, a problem that can trouble many SLR cameras with bright lenses (f < 2.8). With the Sigma USB dock and associated Optimization Pro software, you can even install a software update for this lens, or fine-tune the AF settings.
Given the high brightness, it's remarkable how little vignetting this lens showed. Granted, the Sigma 50 mm f/1.4 Art is designed for a camera with a full-frame sensor, so it's logical that the degree of vignetting on a camera with a smaller APS-C sensor is lower. Even so, the vignetting that this lens shows at f/2 is lower than a great many zoom lenses show on APS-C even at f/8.
Not only a portrait lens: Take a walk in the woods on a drizzly day, and you'll be surprised how little light remains. The brightest lenses at full opening deliver contrast-poor, hazy images. The background is nicely blurred, but the difference in sharpness between subject and background is not spectacular. With the Sigma 50 mm f/1.4 Art it is—also on a Canon camera with an APS-C sensor.
This lens can be used for the most demanding forms of architecture photography.
On this point, too, there is nothing to criticize about the Sigma 50 mm f/1.4 Art. With 0.2% pincushion distortion, it's almost 50% lower than on a camera with a full-frame sensor. Just very good.
We actually could not catch this lens with flare or ghosts.
Even in the practice shots that we made, where we photographed directly into the sun, we encountered no flare or ghosts. In the partial enlargement shown here, you see an example, where color bokeh (green and purple edges at sharp contrast transitions in front of and behind the focal point) is visible. Practically all bright (f < 2.8) lenses show color bokeh. For the Sigma 50 mm f/1.4, it's noticeable how very little it's present. This is the worst case that we found in the practice shots.
The sharpness in the outer corners is already extremely high—especially for a bright lens—at full aperture. Even so, it visibly increases if you stop down 1 stop. Below you see two image excerpts from the corners of test images made at f/1.4 and f/2.8. The contrast and sharpness increase further. It's really not a difference of day and night like we're used to seeing from bright lenses.
Klick on the image for a larger version.
Lateral chromatic aberration—that is to say: blue and red edgest at contrast transitions in the corners of the image—is suppressed very well, thanks to the application of a high-quality aspherical and 3 ultra-low dispersion lens elements, as you can see in the lens design earlier on this page. In this test shot, you see that there is no sign of front or back focus and that longitudinal chromatic aberration ("color bokeh") under normal circumstances is not disturbingly present.
The quality of a lens (types of glass and aspherical lenses) may have a greater impact on the bokeh than the size of the sensor. It used to be that the more aperture lamellae, the nicer the bokeh. Currently, lamellae are often rounded, so that a good lens can get by with fewer lamellae, as far as the bokeh is concerned. The Sigma 50 mm f/1.4 Art has nine—that's a lot—rounded lamellae. In our standard review set-up for bokeh, with a plant in the foreground and various light sources in the background at about 1 meter, the Sigma 50 mm 1.4 Art on a Canon 650D gave a nice bokeh, that you can't distinguish from the best lenses on a camera with a full-frame sensor. The bokeh in our practice shots was also exemplary.
Move your mouse over the image for a 100% partial enlargement.
Conclusion: Sigma 50 mm 1.4 Art, reviewed on a Canon 650D
WYSIWYG score: This table shows the performance of this lens if you store the files in the camera as jpg, where you have all available in-camera corrections applied. This score gives you for this lens/test camera combination: "What you see is what you get".
test camera: Canon 650D
Pure RAW score: This table shows the performance of this lens if the file is stored in the camera as a RAW file. This score approaches the intrinsic quality of this combination of lens and camera.
Extremely high image quality: sharp, contrast-rich from full aperture, little chromatic aberration, distortion or vignetting, extremely little trouble from backlighting, including a beautiful bokeh
Very sharp price, given the quality offered
Actually none, but if one has to be named: 10 cm long and more than 800 grams in weight; 150 grams lighter than the Zeiss Otus 55 mm f/1.4 ;-)
This Sigma 50 mm f/1.4 Art may well be the wet dream of many enthusiastic prosumers, professionals or ambitious amateur photographers.
On a Canon SLR camera with an APS-C sensor, this looks like a bright portrait lens, or short telephoto lens, with a sharpness and bokeh that give nothing up to many portrait lenses on a camera with a full-frame sensor. Of all the lenses with a fixed focal length and all zoom lenses that we have reviewed on a Canon camera with an APS-C sensor, the Sigma 50 mm f/1.4 Art scores the highest in our list of reviews. Only the Sigma 18-35 mm Art f/1.8, set at 35 mm, can keep up with this optical powerhouse. As far as vignetting, chromatic aberration, flare, ghosts and distortion are concerned, the Sigma 50 mm f/1.4 Art on a Canon 650D camera scores better than most lenses on a Canon 5D MK3 or a Canon 1Dx. Combine that with a bokeh that gives nothing up to the bokeh of many lenses on a camera with a full-frame sensor, and you can talk with confidence about a dream lens. And with a list price of 879 euros—although that's a lot of money—this is an affordable dream as well.
Author: Ivo Freriks
With Camera Review Stuff I hope to make a modest contribution to the pleasure that you get from photography. By testing cameras and lenses in the same way, evluating the results and weighing up the pros and cons, I hope to help you find the right camera or lens.