Sigma Launches 20mm f/1.4 DG HSM Art

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Who Dey
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Jul 20, 2010
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Truly wide and truly fast, the Canon EF mount 20mm f/1.4 DG HSM Lens is a member of the venerable Art series of Global Vision lenses from Sigma and pairs a sophisticated optical design with a robust physical construction. Comprised of 15 elements in 11 groups, the lens design includes both “F” Low Dispersion (FLD) and Special Low Dispersion (SLD) glass to significantly reduce chromatic and spherical aberrations, as well as limit distortion for clean, sharp, and evenly illuminated imagery. A Super Multi-Layer Coating has also been applied to minimize surface reflections, flare, and ghosting for increased contrast and color accuracy. The wide focal length and consistent image quality make this lens especially suitable for landscape, interior, architectural, and astrophotography applications, while the fast f/1.4 maximum aperture deems it ideal for natural and low-light shooting.</p>
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<p>Complementing the optical performance is an equally adept Hyper Sonic Motor, which provides fast, smooth, and near-silent autofocus performance. This focusing motor also enables full-time manual focus override at any time just by rotating the focus ring for refined manual control and focusing as close as 10.9″. The lens barrel is constructed using a Thermally Stable Composite material, which supports working in a wide variety of temperatures and conditions, and the lens mount is constructed from brass for long-term durability and mounting accuracy. Additionally, this lens is also compatible with the optional Sigma USB Dock for fine-tuned control over focusing parameters and other lens characteristics.</p>
<ul>
<li>As part of the Art line within Sigma’s Global Vision series, this lens’ is designed to achieve truly notable optical performance and is ideally suited for creative and artistic applications.</li>
<li>Prime wide-angle 20mm f/1.4 lens is designed for full-frame format Canon EF mount DSLRs, and can also be used with APS-C models where it will provide a 32mm equivalent focal length.</li>
<li>Fast f/1.4 maximum aperture is well-suited for working in low-light conditions and also provides greater control over the focus position when using shallow depth of field techniques.</li>
<li>Both FLD glass and five SLD elements have been incorporated within the lens design to correct for chromatic aberrations throughout the entire focusing range and help to ensure high image sharpness, clarity, and contrast regardless of focus point or aperture setting.</li>
<li>A Super Multi-Layer Coating has been applied to lens elements in order to minimize lens flare and ghosting and contribute to producing contrast-rich and color-neutral imagery, even in backlit conditions.</li>
<li>The integrated HSM (Hyper Sonic Motor) realizes quick and quiet autofocusing, which is further complemented by an optimized AF algorithm to produce smoother focusing performance. The HSM also permits full-time manual focus control simply by rotating the focus ring at any time.</li>
<li>A rounded nine-blade diaphragm helps to produce an attractive out-of-focus quality.</li>
<li>Petal-shaped lens hood helps to reduce lens flare when working in strong lighting conditions and also offers some protection to the front element of the lens.</li>
<li>The lens is constructed using a Thermally Stable Composite (TSC) material, along with traditional metals, for greater precision and use in wide temperature variations.</li>
<li>The bayonet mount is constructed from brass for ensured accuracy and durability.</li>
<li>This lens is compatible with the optional Sigma USB Dock for fine-tuning different lens characteristics and updating its firmware.</li>
</ul>
<p><strong>Preorder Sigma 20mm f/1.4 DG HSM Art $899: <a href="http://www.bhphotovideo.com/c/product/1191178-REG/sigma_20mm_f_1_4_art_lens.html/bi/2466/kbid/3296" target="_blank">B&H Photo</a></strong></p>
 
Very interested in seeing a few sample images from this lens, especially in from an astrophotographic point of view. Price seems incredibly reasonable as well. This could be the one I've been waiting for!

d.
 
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DLD said:
Anybody have a clue as to the filter size? I figure 77mm isn't totally out of the question however the design could lead to softer/darker corners wide open I assume it's the new 82mm standard?
I am thinking that there is no filter thread. The fact that it is a highly-corrected (hopefully) f/1.4...I think that we have a round, bulbous front end. That looks like a fixed hood and B&H usually has all specs when listing an item, but their site says: "Filter Size- Specs not listed by manufacturer". So I am betting it will need an over-the-hood filter holder....which is REALLY unusual for a 20mm lens..but this is an unusual 20mm that is pushing the limits.
Right?
 
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Yes, fixed hood and no filter threads. There is a lot more info on SiGMA's webpages. 2.3 stops of corner vignetting doesn't sound too bad. The wide-open MTF charts don't look too impressive (not much to compare to) but the coma performance will be decisive for me (as for many others). The other ARTs have been a bit of a disappointment in this regard, so I really hope this one holds up.
 
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http://www.sigma-global.com/en/lenses/cas/product/art/a_20_14/features.html

http://www.sigma-global.com/en/lenses/cas/product/art/a_24_14/features.html

Spend an hour comparing these two pages side by side: mtf charts, vingetting, optical construction formula, distortion chart.

To me, according to provided charts on these pages, the performance of the new 20/1.4 Art is almost identical to 24/1.4 Art. MTF charts are so close that I had to open both of these pages side by side to spot the differences.

The major difference in the bulging large double aspherical front element on the 20/1.4 Art. Will that front element make all the difference in the coma department remains to be seen.
 
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epsiloneri said:
Yes, fixed hood and no filter threads. There is a lot more info on SiGMA's webpages. 2.3 stops of corner vignetting doesn't sound too bad. The wide-open MTF charts don't look too impressive (not much to compare to) but the coma performance will be decisive for me (as for many others). The other ARTs have been a bit of a disappointment in this regard, so I really hope this one holds up.

Well, lets compare this to canons nearest, the 24f1.4L

EF24_14LIIU_mtf.gif


and here's the sigma

mtf.gif


take the black lines on the 24 vs the red and green on the 20
 
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Alex_M said:
http://www.sigma-global.com/en/lenses/cas/product/art/a_20_14/features.html

http://www.sigma-global.com/en/lenses/cas/product/art/a_24_14/features.html

Spend an hour comparing these two pages side by side: mtf charts, vingetting, optical construction formula, distortion chart.

To me, according to provided charts on these pages, the performance of the new 20/1.4 Art is almost identical to 24/1.4 Art. MTF charts are so close that I had to open both of these pages side by side to spot the differences.


The major difference in the bulging large double aspherical front element on the 20/1.4 Art. Will that front element make all the difference in the coma department remains to be seen.
Yes, I suspect that like the 24mm Art lens, decent coma by f/2.8. But that isn't a terrible outcome because vignette is much better at f/2.8, so still a little better than 2.8 rivals for astro. Just guessing, but getting decent coma at f/1.4 would seem to be beyond state of the art.
 
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Apparently, Dual Aspherical front element can and should improve situation with coma. There is a hope!

http://www.mir.com.my/rb/photography/opinion/html/aspherical.htm

"... Fast lenses, at times has problem maintaining its optical performance at widest opening, especially in situation where the illumination is dim. A aspherical lens can assure optimum correction of coma. Like images of scenes with small points of light - bright point sources of light near the edges of the picture appear as dots rather than comet-shaped blurs. Some newer generation of fast lens, like the world's fastest 28mm lens, the AF Nikkor 28mm f/1.4D, or the recent Canon's super fast EF 50mm f1.0 L use an aspherical element to ensure compact size and to obtain superb performance by eliminating sagittal, or arrow shaped, coma, even at its widest aperture...."
 
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epsiloneri said:
Yes, fixed hood and no filter threads. There is a lot more info on SiGMA's webpages. 2.3 stops of corner vignetting doesn't sound too bad. The wide-open MTF charts don't look too impressive (not much to compare to) but the coma performance will be decisive for me (as for many others). The other ARTs have been a bit of a disappointment in this regard, so I really hope this one holds up.

Oh...DUH! LOL!....thanks for the link...there is a lot more info at the Sigma page than there is in the press release....That link should be at the top of this page with the post. ;D
 
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