Review Sigma 50 mm 1.4 Art @ Canon 650D
A smash on APS-C as well.
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
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.
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.
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.
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.
|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
Use the Lens Comparison or look in our list of reviewed lenses to compare this lens with other lenses.