| 词条 | Sigma 8–16mm f/4.5–5.6 DC HSM lens |
| 释义 |
| name = 8–16mm f/4.5–5.6 DC HSM | image = Sigma 8-16 Lens for Canon.jpg | maker = Sigma | feat-is = n | focusdrive = Ultrasonic motor | feat-sbf = | feat-macro = n | feat-special = | type = | application = Consumer Super Wide-Angle Zoom for Digital SLRs | flength = 8–16 mm | fov = 114.5° – 75.7° | aperture = f/4.5/22 – f/5.6/29 | groups = 11 | elements = 15 | diaphragm = 7 | close-dist = 24 cm (9.4 in) | max-mag = 1:7.8 | weight = 555 g (16.4 oz) | max-diameter = 75 mm | max-length = 106 mm | filter = NA | hood = y | av-horiz = | av-vert = | av-diag = | start = February 2010 | msrp = $1100 USD }} The Sigma 8–16mm lens is an enthusiast-level, ultra wide-angle rectilinear zoom lens made by Sigma Corporation specifically for use with APS-C small format digital SLRs. It is the first ultrawide rectilinear (non-fisheye lens) zoom lens with a minimum focal length of 8 mm, designed specifically for APS-C size image sensors.[1] The lens was introduced at the February 2010 Photo Marketing Association International Convention and Trade Show.[2] At its release it was the widest viewing angle focal length available commercially for APS-C cameras.[3][3] It is part of Sigma's DC (Digital Camera) line of lenses, meaning it was designed to have an image circle tailored to work with APS-C format cameras.[3] The lens has a constant length regardless of optical zoom and focus with inner lens tube elements responding to these parameters.[4] The lens has hypersonic zoom autofocus. The lens is sold in versions that fit the bayonet mounts of Nikon, Canon, Sigma, Sony/Minolta and Pentax APS-C cameras.[7] Specifications and measurementsThe lens measures {{convert|106|x|75|mm|in}} and weighs {{convert|555|g|lbs}}. It has a bulb-like aspherical lens, similar to notable wide-angle and fisheye lenses such as the Nikon AF-S NIKKOR 14-24mm f/2.8G ED, Nikon AF DX Fisheye-Nikkor 10.5mm f/2.8G ED, or Tokina AT-X 107 DX AF 10-17mm f/3.5-4.5 fisheye lens.[7] Because of the shape of front element, it is not compatible with many filters, including UV filters, but the frontal exposure is rectified by a petal-shaped lens hood element.[4] Because the lens has a permanent lens hood affixed, it comes with a friction-fit aluminum element, variously described as a sleeve, ring or shroud,[3] that surrounds the hood to enable the placement of a front cap on the lens.[4] PC Magazine{{'s}} Jim Fisher says the lens is relatively large and heavy;[5] A reviewer at photozone.de says that for a wide-angle lens the dimensions are unusually narrow but long.[4] The sleeve is threaded, making it compatible with 72mm filters, but vignetting is severe with the sleeve in place.[3] The construction is plastic although the lens' rear mount is metal.[3][7] The distance meter is recessed inside a window, but no depth of field meter or infrared index is present.[3] The 7/8" zoom ring is made of raised rubber ridges and operates over a 75 degree turning radius. The focus ring is similarly constructed with more closely spaced ridges and a 100 degrees of turning action. The ridges of both rings are parallel to the lens.[3] The only physical controls on the lens are the AF/MF toggle switch and the two rings, controlling the zoom and focus.[5] The lens does not have image stabilization. This is common for wide-angle photography which can be performed well using hand-held techniques.[6] Over the range of focal lengths, the minimum and maximum aperture vary.[7] Autofocus{{multiple image| align = left | direction = vertical | width = | image1 = 20120904 Canon Rebel T3i with Sigma 8-16mm f4.5-5.6 DC HSM lens2.jpg | width1 = 220 | alt1 = | caption1 = | image2 = 20120904 Canon Rebel T3i with Sigma 8-16mm f4.5-5.6 DC HSM lens and sleeve2.jpg | width2 = 220 | alt2 = | caption2 = | header = | header_align = | header_background = | footer = Canon Rebel T3i with Sigma 8–16mm f/4.5–5.6 DC HSM lens. Bottom with sleeve and cap | footer_align = | footer_background = | background color = }} The lens features a hypersonic zoom motor for its autofocus, which is considered to be a fast and quiet design.[4][6] In addition, manual override is allowed in the single-shot autofocus mode.[4] The lens, which focuses internally, has one of the lowest maximum magnification measurements in its class (which includes the Canon 10–18mm and 10–22mm, Sigma 10–20mm f/3.5 and Sigma 10–20mm f/4–5.6 EX DC HSM, Tamron 10–24mm f/3.5–4.5 DI II, Nikon 10–24mm f/3.5–4.5G ED AF-S DX, and Tokina 11–16mm f/2.8 AT-X Pro DX lenses).[7][3] The lens' autofocus feature is not functional with Pentax ist* series and K100D DSLR cameras that do not support hypersonic zoom mechanics.[1] The lens is capable of focusing from infinity to minimum focusing distance and back in under a second: so micro focusing is rapid.[7] However, because of the narrow focus range (0.13x) the lens is not suitable for macro photography.[7] DistortionThe lens exhibits significant distortion in keeping with the problems of wide-angle lenses.[4] The complex barrel distortion is approximately 2.9% at 8 mm focal length but is fairly insignificant as the focal length is raised above 12 mm, according to Photozone.de.[4] PC Magazine reports 3.1% distortion at 8 mm and 0.7% at 12 mm.[5] It also reports that distortion switches to pincushion distortion of 1.4% at 16 mm.[5] SLAR Gear reports that the point of convergence between barrel and pincushion is about 13 mm.[7] Foreground subjects seem abnormally large compared to similar background subjects with this lens.[3] By combining the wide angle focal lengths with narrow apertures, the lens provides strong depth of field rather than making blurred backgrounds.[3] The lens is constructed with a hybrid aspherical lens that when combined with two glass mold elements provides excellent correction for distortion as well as astigmatism.[1] Vignetting and field of viewAs all lens systems, natural vignetting (gradual reduction of an image's brightness from the center towards the periphery) is present due to Lambert's cosine law – this becomes more pronounced at shorter focal lengths.[4] Wide open at 8 mm, about 0.75 EVs of shading are apparent at the corners, while at 16 mm only about 0.25 EV of shading is noticeable when comparing the corners to the center.[7] For most of the focal length range of the lens, there is between a half stop and third stop of corner shading.[7] Alternatively, stopping down to higher f-numbers lessens vignetting.[8] {{multiple image| align = center | direction = horizontal | width = | image1 = 20120907 Sigma on a full frame at 8mm.JPG | width1 = 150 | alt1 = | caption1 = | image2 = 20120907 Sigma on a full frame at 12mm.JPG | width2 = 150 | alt2 = | caption2 = | image3 = 20120907 Sigma on a full frame at 16mm.JPG | width3 = 150 | alt3 = | caption3 = | header = | header_align = | header_background = | footer = The restriction of the field of view due to the build in lens hood becomes visible on a full-frame digital SLR (left to right: 8 mm, 12 mm and 16 mm focal length). | footer_align = | footer_background = | background color = }} The lens is equipped with a full-frame digital SLR-compatible mount allowing the usage of both APS-C sized cameras and formats larger than APS-C – the build in lens hood however visibly restricts the field of view (FOV) on formats larger than APS-C – see example above.[1][7] The FOV in APS-C sized cameras is further restricted at shorter focal lengths if the front cap adaptor ring is not removed – see example below.[4] {{multiple image| align = center | direction = horizontal | width = | image1 = 20120905 Sigma 8-16mm f4.5-5.6 DC HSM lens 8mm vignetting.JPG | width1 = 90 | alt1 = | caption1 = | image2 = 20120905 Sigma 8-16mm f4.5-5.6 DC HSM lens 10mm vignetting.JPG | width2 = 90 | alt2 = | caption2 = | image3 = 20120905 Sigma 8-16mm f4.5-5.6 DC HSM lens 12mm vignetting.JPG | width3 = 90 | alt3 = | caption3 = | image4 = 20120905 Sigma 8-16mm f4.5-5.6 DC HSM lens 14mm vignetting.JPG | width4 = 90 | alt4 = | caption4 = | image5 = 20120905 Sigma 8-16mm f4.5-5.6 DC HSM lens 16mm vignetting.JPG | width5 = 90 | alt5 = | caption5 = | header = | header_align = | header_background = | footer = If the front cap adaptor ring is not removed, the field of view becomes restricted even on an APS-C digital SLR camera (left to right: 8 mm, 10 mm, 12 mm, 14 mm and 16 mm focal length). | footer_align = | footer_background = | background color = }} ResolutionThe lens' modulation transfer function (MTF) metrics for its image resolution (sharpness) were described as "surprisingly impressive...throughout the entire zoom range" by Photozone.de.[4] The sharpness, in terms of line widths per picture height (LW/PH), is most uniform at 8 mm (especially near the f-number of 8 where it is even throughout the image) with strong numbers at the center, borders and corner. Higher focal lengths were less impressive.[4] Optical tests were consistent with lab results pointing to excellent sharpness.[9] However, exposure testing seems to belie the stated f-number capabilities of the lens, since stopping down from widest aperture did not change results, according to Gietler.[9] At its widest aperture, the sharpness does not meet the 1800 threshold at either 8 mm (1572, f/4.5) or 12 mm (1356, f/5), but at 16 mm (f/5.6) it achieves over 2000 lines per picture height. However, stopping down improves the sharpness at all focal lengths, according to PC Magazine. At 8 mm, 1800 is reached at f/8, while at 12 mm it is still only at 1509 by f/8.[5] The image quality is asymmetric with better performance on the right side.[3] At 8 mm and f/4.5, it has 1 blur unit in the center and 1.5 in the corners.[7] Although the images are slightly sharper at f/5.6, SLR Gear claims sharpness declines significantly at f/11 to almost 2 blur units with further stopping down increasing blur to 3.5 at f/22.[7] At the longer focal lengths for this lens, stopping down to f/29 yields a 5 blur unit result.[7] Chromatic aberrationThe lens is the first that incorporated Sigma's FLD glass elements, designed to correct color aberrations like fluoride glass does.[4] Chromatic aberrations are indeed superior to earlier Sigma wide-angle lenses. In fact, although they might be noticeable at 100% image magnification, they are not at the magnifications now common with prints relative to the number of megapixels that images are commonly captured at.[4] According to Sigma's website, Super Multi-Layer Coating reduces flare and ghosting.[1] As one zooms out with this lens chromatic aberration becomes significant at the corners.[7] Action photographyThe aperture stop-down focal lengths make the lens a laggard among wide-angle lenses.[3] Thus, it is not strong at gathering light for stop action photography. However, DSLR cameras have improved at higher ISO settings.[3] However, wide-angle photography (below 16mm) continues to need stronger lighting than is possible by built in flashes if trying to make up for low light situations.[3] Close focus and macroAt 8 mm and 16 mm, respectively, the lens is able to focus on an area {{convert|12.25|in|cm}} and {{convert|7|in|cm}} in width.[6] Although the official close focus distance is {{convert|24|cm|in}},[1] Scott Gietler reported that by using the spot-focus mode, rather than multiple focus points, he was able to achieve a {{convert|3|in|cm}} minimum working distance (glass to subject).[6] Critical commentaryThe lens is useful for deliberative shots by landscape photographers and other skilled artists.[5] The challenge of the vast field of view may be overcome by some casual users.[5] Car photographers benefit from the new perspective of this lens.[3] The lens was a 2010 American Photo Editor's Choice.[1] Notes1. ^1 2 3 4 5 6 {{cite web |author=Sigma Corporation |title=8-16mm f/4.5-5.6 DC HSM |url=http://www.sigmaphoto.com/shop/8-16mm-f45-56-dc-hsm-sigma |year=2010|accessdate=2012-08-26}} 2. ^{{cite web|url=http://www.dpreview.com/articles/pma2010/|title=PMA 2010 Show Report|accessdate=2012-08-31|date=2010-05-04|work=Digital Photography Review|deadurl=yes|archiveurl=https://web.archive.org/web/20120824002220/http://www.dpreview.com/articles/pma2010/|archivedate=2012-08-24|df=}} 3. ^1 2 3 4 5 6 7 8 9 10 {{cite web|url=http://www.the-digital-picture.com/Reviews/Sigma-8-16mm-f-4.5-5.6-DC-HSM-Lens-Review.aspx|title=Sigma 8-16mm f/4.5-5.6 DC HSM Lens Review |first=Bryan |last=Carnathan |accessdate=2012-08-29|date=2010-11-22|publisher=Digital-picture.com}} 4. ^1 2 3 4 5 6 7 8 9 10 11 12 13 {{cite web|url=http://www.photozone.de/canon-eos/515-sigma816f4556apsc|title=Sigma AF 8-16mm f/4.5-5.6 DC HSM - Lab Test / Review |accessdate=2012-08-29|date=2010-05-01|publisher=Photozone.de}} 5. ^1 2 3 4 5 6 {{cite web|url=https://www.pcmag.com/article2/0,2817,2407685,00.asp|title=Sigma 8-16mm F4.5-5.6 DS HSM|accessdate=2012-08-29|date=2012-08-01|work=PC Magazine|author=Fisher, Jim}} 6. ^1 2 3 4 5 6 {{cite web|url=http://www.uwphotographyguide.com/sigma-8-16mm-specs|title=Sigma 8-16mm Specs, Design, Focus and Operation|accessdate=2012-08-30|work=Underwater Photography Guide|author=Gietler, Scott}} 7. ^1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 {{cite web|url=http://slrgear.com/reviews/showproduct.php/product/1330/cat/31|title=Sigma 8-16mm f/4.5-5.6 DC HSM (Tested)|accessdate=2012-09-06|date=2010-08-26|work=SLR Gear|author=Alexander, Andrew}} 8. ^{{cite web|url=http://www.uwphotographyguide.com/sigma-8-16mm-vignette-distortions|title=Sigma 8-16mm chromatic aberration, vignetting, barrel distortion, flare|accessdate=2012-08-30|work=Underwater Photography Guide|author=Gietler, Scott}} 9. ^1 {{cite web|url=http://www.uwphotographyguide.com/sigma-8-16mm-sharpness|title=Sigma 8-16mm sharpness tests|accessdate=2012-08-30|work=Underwater Photography Guide|author=Gietler, Scott}} External links
6 : Camera lenses introduced in 2010|Sigma lenses|A-mount lenses|EF-S-mount lenses|F-mount lenses|K-mount lenses |
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