The Blog: See what
Sigma is saying.

08.28.2015

Sigma Art lenses are renowned for razor-sharp detail on the focal plane, even at widest apertures. It seems simple, enough, doesn’t it? If you are buying a very fast aperture lens, you will want to take advantage of the extra light-gathering power, not just for the through-the viewfinder experience, but also for the on-the-sensor feel of an F1.4, F1.8 or F2 aperture, whether in dim lighting situations to keep ISOs low, or simply for the aesthetic that a very shallow focal plane offers and how the foreground and background are rendered.

A raindrop hangs from a leaf as seen through the Sigma 50mm F1.4 DG HSM | Art lens wide open at F1.4. 1/200 F1.4 ISO 400 on a Canon EOS 6D. The focal point is sharp and crisp, while the depth of field is ridiculously shallow.

A raindrop hangs from a leaf as seen through the Sigma 50mm F1.4 DG HSM | Art lens wide open at F1.4. 1/200 F1.4 ISO 400 on a Canon EOS 6D. The focal point is sharp and crisp, while the depth of field is ridiculously shallow.

The laws of optical physics do insist that every lens will be a bit sharper overall when the aperture is stopped down slightly, and the same holds true for Sigma Art lenses. This is most noticeable on test targets, which, honestly, are one of the most boring photo subjects ever. In real world situations, Sigma Art lenses are growing more legendary each day for the total imaging performance this gear delivers, whether wide open,  or stopped down a touch.

Razor thin focus on a hibiscus flower, which is mirrored in color by the red umbrellas blurred in the background. Sigma 24-35mm F2 DG HSM | Art wide open at F2 at 35mm on the 6D. 1/1000 at F2.0 ISO 100

Razor thin focus on a hibiscus flower, which is mirrored in color by the red umbrellas blurred in the background. Sigma 24-35mm F2 DG HSM | Art wide open at F2 at 35mm on the 6D. 1/1000 at F2.0 ISO 100

Now, shooting at the absolute widest aperture on a given lens isn’t always necessary, or necessarily desired, due to the very shallow depth of field, which can be mere centimeters thin when wide open and close-focused; but knowing that the slim focal plane sharpness will be crisp and pleasing when that is what the composition calls for is simply perfect. 

A dune flower faces the morning sun, as seen through the Sigma 35mm F1.4 DG HSM | Art lens, wide open at F1.4. Notice how shallow the depth of field is, when close focused, at widest apertures. Captured on a classic 5D. 1/4000 F1.4 ISO 100.

A dune flower faces the morning sun, as seen through the Sigma 35mm F1.4 DG HSM | Art lens, wide open at F1.4. Notice how shallow the depth of field is, when close focused, at widest apertures. Captured on a classic 5D. 1/4000 F1.4 ISO 100.

It was necessary to stop down to F2.2 for this image of a cherry tree in bloom; simply because the shutter speed and ISO combination demanded it! We were overexposed at 1/8000 ISO 100 while wide open, which hits the wall of maximum shutter speed and lowest ISO on the original 5D.

It was necessary to stop down to F2.2 for this image of a cherry tree in bloom; simply because the shutter speed and ISO combination demanded it! We were overexposed at 1/8000 ISO 100 while wide open, which hits the wall of maximum shutter speed and lowest ISO on the original 5D.

A fast-aperture lens that needs to be stopped down significantly to ensure decent image quality just doesn’t make sense any more; and that’s a big part of the optical design philosophy of the Art lenses. These lenses excel at focal plane sharpness, even wide open!

Sunlight reflected off a brook offers great bokeh behind blooming branchlets as seen through the 50mm F1.4 DG HSM | Art lens. 1/8000 F1.8 ISO 100.

Sunlight reflected off a brook offers great bokeh behind blooming branchlets as seen through the 50mm F1.4 DG HSM | Art lens. 1/8000 F1.8 ISO 100.

All Sigma Art lenses are able to be tuned with the USB Dock for Microfocus adjustments, which can help improve critical focus to ensure peak sharpness: when wide-open, there’s much less “wiggle room” between the AF sensors and the focal plane. So being able to tweak this in four zones on a prime and sixteen zones on a zoom helps ensure peak performance.

Repetitive patterns, such as this rail fencing, helps visualize the difference stopping down the aperture can make on a scene. Notice how the railing is in focus on the right of the frame in this shot made at F1.8 on the 18-35mm at F1.8.

Repetitive patterns, such as this rail fencing, helps visualize the difference stopping down the aperture can make on a scene. Notice how the railing is in focus on the right of the frame in this shot made at F1.8 on the 18-35mm at F1.8.

And here is the same scene shot at F5.6 with the identical focal point and focal distance. Notice how the blur characteristics differ.

And here is the same scene shot at F5.6 with the identical focal point and focal distance. Notice how the blur characteristics differ.

And of course, every Sigma Art lens, like every Sports and Contemporary lens, is individually tested for optical performance on our exclusive A1 MTF Device. And Sigma Art, Sports and Contemporary lenses are the only autofocus lenses available with exclusive Mount Conversion Service, swappable between all supported lens mounts.

A starfish as seen through the 30mm F1.4 DC HSM | Art lens on a Reb T3i at F1.8 to increase the DOF ever-so-slightly. 1/3200 F1.8 ISO 100.

A starfish as seen through the 30mm F1.4 DC HSM | Art lens on a Reb T3i at F1.8 to increase the DOF ever-so-slightly. 1/3200 F1.8 ISO 100.

The SuperBee icon on a classic muscle car. This is the sister of the RoadRunner memorialized by the Modern Lovers. At F1.8 on the 50mm F1.8 DG HSM | Art lens, only the speedy little motorized bee is on the focal plane. We added a new Weather Resistant Circular Polarizer to tame glare and reflections. 1/1250 F1.8 ISO 100 on a 6D.

The SuperBee icon on a classic muscle car. This is the sister of the RoadRunner memorialized by the Modern Lovers. At F1.8 on the 50mm F1.8 DG HSM | Art lens, only the speedy little motorized bee is on the focal plane. We added a new Weather Resistant Circular Polarizer to tame glare and reflections. 1/1250 F1.8 ISO 100 on a 6D.

This was the first image from an Art lens we ever shared on Facebook, made with the 35mm F1.4 DG HSM | Art lens on a Reb T3i. It is wide open at F1.4, and has been one of the most liked and shared Facebook postings.  1/400 F1/4 ISO 100. It really showcased what these lenses are designed to do!

This was the first image from an Art lens we ever shared on Facebook, made with the 35mm F1.4 DG HSM | Art lens on a Reb T3i. It is wide open at F1.4, and has been one of the most liked and shared Facebook postings. 1/400 F1/4 ISO 100. It really showcased what these lenses are designed to do!

A classic cruise, captured at F1.8 on the 50mm Art lens, with a circular Polarizer attached to cut glare, pops both in color and in sharpness from the softened background. 1/1250 F1.8 ISO 100 on a 6D.

A classic car, captured at F1.8 on the 50mm Art lens, with a circular Polarizer attached to cut glare, pops both in color and in sharpness from the softened background. 1/1250 F1.8 ISO 100 on a 6D.

The circular polarizer helps keep colors crisp and cut glare and reflections on the steering wheel and dashboard of a classic Thunderbird seen through the 50mm F1.4 DG HSM | Art at 1/320 F2.8 ISO 400 on a 6D.

The circular polarizer helps keep colors crisp and cut glare and reflections on the steering wheel and dashboard of a classic Thunderbird seen through the 50mm F1.4 DG HSM | Art at 1/320 F2.8 ISO 400 on a 6D.

And a classic beach cruiser bike, seen through the 50mm F1.4 Art at F4, for a touch more sharpness in the background characteristics such as the clouds and beach umbrellas. 1/1000 F4 ISO 100 on a 6D. WR-Circ Polarizer to add pop to the sky and clouds.

And a classic beach cruiser bike, seen through the 50mm F1.4 Art at F4, for a touch more sharpness in the background characteristics such as the clouds and beach umbrellas and make sure all the boards of the boardwalk were captured crisply. 1/1000 F4 ISO 100 on a 6D. WR-Circ Polarizer to add pop to the sky and clouds.

I chose F9 as the aperture here, with the assistance of a tripod, to ensure that the entire lifeguard stand would be tack-sharp in this moonset photo captured on a classic 5D at morning twilight. 1 second exposure, F9, ISO 100. Manfrotto Carbon Fiber Tripod. Moon exposure layered in and masked in from previous image in wide AEB sequence.

I chose F9 as the aperture here, with the assistance of a tripod, to ensure that the entire lifeguard stand would be tack-sharp in this moonset photo captured on a classic 5D at morning twilight. 1 second exposure, F9, ISO 100. Manfrotto Carbon Fiber Tripod. Moon exposure layered in and masked in from previous image in wide AEB sequence.

Wide open, or stopped down a little to increase total depth of field and ground rendering characteristics, the Sigma Art lenses, are always incredibly sharp. And in the world of modern digital photography and cinematography, this is exactly what you would and should expect from your fast-aperture prime and zoom lenses. 

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