Sigma 24

It is always exciting to bring in a new Sigma Art lens and covering the normal, most-commonly-used focal length range with an f/2.8 aperture combined with optical stabilization definitely raised the anticipation level for this one.Sigma"s "It’s Here to lớn Steal the Spotlight" statement didn"t hurt either.

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The Sigma 24-70mm f/2.8 DG OS HSM Art Lens brings the "Global Vision" treatment to Sigma"s version of this highly popular lens model.

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Focal Length Range

There is a reason that the focal length or focal length range is included in the sản phẩm name of every DSLR lens produced today.Of utmost importance in lens selection is acquiring the right focal length or, in the case of a zoom lens, the right range of focal lengths that cover your needs.Focal length is especially important in that it drives focus distance choices, which in turn determine perspective for the desired composition.

The good news about the 24-70mm focal length range, considered "normal" & covering angles of view ranging from wide angle through short telephoto, is the great general purpose usefulness it has.Practically all kits can make use of a lens covering this range.

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A 24-70mm lens is an essential part of many landscape & cityscape photography kits.At the 24mm end, this lens provides a very wide angle of view, able lớn simply take in a vast scene (27mm is featured above at Emerald Lake, Rocky Mountain National Park) and/or khổng lồ show a strong perspective, creating a sense of presence in an image (27mm also used below at Alluvial fan hâm mộ Falls, Rocky Mountain NP).

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Still, 24mm is not so wide that composition becomes overly challenging.And, having the ability khổng lồ zoom slightly was apparently helpful to lớn me in the last two situations shared.

Using the 70mm end of the focal length range, smaller portions of a scene can be isolated.Distant mountains will appear larger in proportion to closer elements & closer details, such as the knot in a log, can be focused on.

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A 24-70mm lens is often a requirement in a wedding photographer"s kit và an f/2.8 version of this lens often becomes the most-used option in that kit.At 24mm, environmental portraits that include the venue can be captured và by 70mm, people can be framed tight enough for head và shoulder portraits while retaining pleasing perspective.This lens will work well for photographing a wide variety of events, from parents capturing informal birthday parties at home to photojournalists covering formal galas at large venues.

Architecture photographers are typically looking for linear-distortion-free lenses khổng lồ keep their buildings & walls straight và though prime lenses are often utilized for this purpose, zoom lenses nearly always have near-distortion-free focal lengths ideal for such work.Selecting the lowest distortion focal length (around 28-30mm) takes care of the distortion problem (and removal during post processing is always an option at other focal lengths).

Sports photographers able khổng lồ get close khổng lồ their subjects (such as basketball shot from over or under the net) or wanting to capture a wider/environmental view of their events appreciate this focal length range.This focal length range especially complements a 70-200mm lens very well for sports uses.

Fashion, portraiture, weddings, parties, events, documentary, lifestyle, travel, sports, architecture, land/city/nightscapes, around-the-house needs, general studio applications including product photography & much more.I"m just getting started into the danh mục of uses for this lens và the range of video uses for this lens is as broad as for stills.

Framing narrower on APS-C cameras (full frame 36-105mm equivalent angle of view), the 24-70mm lens" uses shift away from wide angle landscapes/cityscapes/nightscapes & environmental portraits toward portraiture including more tightly-framed portraits.Most of the uses for this lens on an APS-C camera remain the same otherwise.

I"ll take you to lớn the Alluvial fan hâm mộ Falls area in Rocky Mountain National Park for an example of what the 24-70mm focal length range looks lượt thích from a full frame toàn thân point of view:

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If you only have one lens or can only take one lens with you, this focal length range might be the ideal choice.

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Max Aperture

With a few exceptions, f/2.8 is the widest aperture available in a zoom lens & majority of those exceptions cover only the smaller APS-C image circle.And, none of the wider-than f/2.8 full frame options reach beyond 35mm.So, the f/2.8 made available over the entire 24-70mm focal length range is, for the most part, best-available.This is a bright lens (significantly brighter than the lenses included in camera kits) and it compares very well in this regard.

A big advantage of a wide aperture is the amount of light transmitted to lớn the imaging sensor, allowing for lower ISO settings and allowing for shutter speeds capable of stopping both camera & subject motion blur in low light.I typically recommend f/2.8 as the minimum aperture opening for indoors sports such as basketball.Also, lenses with an opening wider than a specific aperture (usually f/2.8) enable the higher precision AF capabilities (most often the center AF point) in some cameras and present a brighter viewfinder image than narrower aperture alternatives.

A disadvantage of a wide aperture is the increased physical kích cỡ of the lens elements that are accompanied by a larger size, heavier weight và a higher cost.

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Another big wide aperture advantage is the shallow depth of field available at the widest aperture, enabling distracting background details khổng lồ be rendered out of focus if desired, isolating the subject through the use of shallow depth of field.The example above was captured at this lens" minimum focus distance, 70mm & f/2.8, maximizing the amount of background blur this lens is capable of.

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Image Stabilization

For the longest time, in most DSLR brands, an f/2.8 aperture & optical stabilization were mutually exclusive in a lens covering 24-70mm focal length range.Basically, you could have an f/2.8 aperture or you could have optical stabilization.In recent years, that mutual exclusion has been disappearing & the combination option has been made available by a number of lens manufacturers.And now, with the 24-70mm f/2.8 OS Art lens, Sigma offers their first such lens.

While the f/2.8 aperture is quite wide and alone makes a camera handholdable in low light, optical stabilization dramatically decreases the amount of light necessary for capturing sharp handheld images.While OS does not stop subject motion blur, sometimes OS can be used to lớn intentionally capture motion blur.

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I relied on this lens" OS feature to capture the mountain lake image I shared earlier.I did not have a tripod with me on this hike and wanted lớn use an f/8 aperture for optimal depth of field.While the 1/15 second shutter tốc độ used for that capture at 27mm may not sound amazing, I was in an unstable position, balanced on uneven rocks while trying lớn frame the scene through an opening in the trees.That was on đứng top of just hiking nearly two miles up the mountain at a rather high altitude.I"m certain that this image & the many others I captured on this hike would not have been sharp without the aid of OS (or a tripod).

So, valuable is that OS allows handholding in medium & low light levels when more depth of field is needed, allowing narrower apertures lớn be used without a tripod.When using a circular polarizer filter with narrow apertures (typical for landscapes và cityscapes), OS can be helpful even under a full sun.

Another benefit of OS is that it provides a stabilized image khổng lồ the camera"s AF system.While AF does not seem lượt thích an image unique factor as it has a mechanical role, AF is an extremely important component to the optical system and having a stabilized image allows it khổng lồ make better decisions.OS is also useful for stabilizing the viewfinder, aiding in optimal composition, và for stabilizing video clip recording, creating a handheld result that is much more pleasant khổng lồ watch.

How much does OS help?A lot.Sigma rates the amount of assistance provided by this OS implementation at 4 stops using the CIPA standard.Figure out what max aperture would be required for equivalency for a different perspective on this feature.

With a Canon EOS 5Ds R behind this lens, I had a decent percentage of sharp handheld 24mm results at 01/05 second và still had sharp images at an OK rate at 1/4 second.By 0.3 seconds, that keeper rate had dropped significantly, though good results could still be obtained through very careful technique và with a high enough number of shots to cover the low percentage keeper rate.

A requirement for a sharp image is that subject details vì chưng not cross over image sensor pixels during the exposure.Longer focal lengths, with their higher subject magnification, generally require faster shutter speeds.In this case, at 70mm, the 24-70 Art lens produced a good percentage of sharp results at 1/8 second, a still decent percentage of sharp results were achieved at 1/6 second and even at 01/05 second, a reasonable keeper rate was experienced.Beyond 1/5 second, I experienced a sharp drop in the sharp image rate.

Another differentiator between optical stabilization systems is their audibility.This OS implementation is very quiet with a light click being heard at startup & shutdown.A quiet whirring sound can be heard if the lens is rapidly moved while OS is activated.

In this lens, OS activation often causes the viewfinder image lớn jump slightly khổng lồ different framing & the same often happens when OS deactivates.Very little or no drifting of the composition was noticeable while OS was active và panning a scene was comfortable lớn do.

Optical stabilization is a great asset khổng lồ the already valuable focal length range and wide aperture of this lens.It can save the day at many events.

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Image Quality

My understanding is that a 24-70mm f/2.8 lens, ranging from retrofocus lớn telephoto, is extremely hard to lớn design.With the popularity and usefulness of this focal length range, we see lens manufacturers coming out with new versions of these lenses frequently with this being Sigma"s fourth version since the Sigma 24-70mm f/2.8 EX DG Aspherical DF was introduced in 2001 for an average of a 4-year lifespan.While they could be simply trying khổng lồ stay ahead of reviewers, far more likely is that manufacturers are pouring every bit of technological advancement possible into this lens category.

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The Sigma 24-70mm f/2.8 OS Art Lens design utilizes three SLD (Special Low Dispersion) glass lens elements and four aspherical lens elements working together along with special lens coatings including Sigma"s Super Multi-Layer Coating lớn minimize optical aberrations.

How sharp is the Sigma 24-70mm f/2.8 DG OS HSM Art Lens?That is probably the first question you have in regards to image quality – it was definitely mine.Let"s explore that aspect.

In the center of the frame, this lens has decent sharpness from 24mm through 28mm.By 35mm, results become somewhat softer & similar results are seen through 70mm.

Stop down to f/4 và prepare to be impressed by the center and mid-periphery results.This lens becomes extremely sharp when stopped down one stop & any differences realized by stopping down to f/5.6 are minor in this portion of the image circle.

Taking the testing outdoors, we next look at a pair of center-of-the-frame 100% resolution crops examples.These images were captured using an ultra-high resolution Canon EOS 5Ds R with RAW files processed in Canon DPP (Digital Photo Professional) using the Standard Picture Style và sharpness set to only "1" (0-10 scale).