If you go khổng lồ photograph an important sự kiện (such as a wedding) & had lớn take only one lens, a fast normal zoom would probably be it. It’s the professional’s workhorse.In “full frame” terminology this typically means a 24-70milimet F2.8. Such lenses are optimized for unique và speed. The 3x focal range covers the useful range of moderate wide-angle khổng lồ moderate telephoto. The relatively fast F2.8 maximum aperture is available at all focal lengths. Expensive extra-low dispersion glass and professional materials complete the unique package.

Bạn đang xem: So sánh tamron 17-50 vc và sigma 17-50

So the bottom line is that a 17-50milimet F2.8 is the best chất lượng all-rounder you can stiông chồng in your cheap DSLR’s lens hole.

Mechanical Design

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Despite their plastic exteriors, both lenses feel solid and well put together. Not indestructible, but solid enough. They’re almost exactly the same kích cỡ, và weight (568g vs 569g, as tested).

At the back both have metal mounts (as you would expect). Neither has a rubber gasket against moisture or dust.

The Tamron has a 72milimet filter thread and the Sigma a larger 77mm thread. Smaller filters are cheaper, but 77mm filters are something of a standard for pro lenses & therefore more versatile.

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As with most consumer zooms, both lenses feature inner tubes that extkết thúc when zooming from 17mm khổng lồ 50milimet. Luckily neither lens has a rotating front element meaning polarizing filters can be used without any annoyance. Both feature similarly sized, rubberized zoom & focus rings. The Tamron’s zoom ring was a bit too stiff for my liking.

The Sigma ships with Sigma’s signature “EX” style zipped lens case that is great for travelling, while the Tamron comes without any protective pouch at all. Both lenses come with petal-shaped lens hoods.

Sharpness and contrast

Analytical sharpness vs aperture charts for these lenses can be found on several websites so I decided khổng lồ test them on a real scene, side by side. These shots were all taken with my Nikon D7000 mounted on a tripod, using 5 second self-timer and delayed shutter (khổng lồ eliminate any blurring due to lớn vibrations). The lenses had their stabilization systems switched off since they were tripod mounted. Phase-detect AF was used. Photos were taken in RAW and converted khổng lồ JPG using Adoble Lightroom 4.1. I used identical processing settings for all photographs và didn’t use any lens correction profiles.

The chosen scene was a parking lot next to the beach at Monster, The Netherlands.

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Below you see 1:1 crops from the original images, grouped by focal length and aperture.

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 At 17mm f/2.8 the Tamron was a bit sharper.

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 At 17milimet f/4.0 both lenses performed better, with the Tamron still taking the lead.

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 At 17mm f/5.6 the difference between the lenses more or less disappeared. Centre sharpness is excellent for both while the edges still lag behind somewhat.

Now let’s see if and how the situation changes at 50mm

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At 50mm f/2.8 both lenses show some softness, but the Sigma fares better. The Tamron has a distracting waxy glow khổng lồ its images, even in the centre.

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At f/4.0 both lenses again improve significantly, và the Sigma maintains its lead.

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At f/5.6 the performance of the two lenses is again quite similar (just as at 17mm) but the Sigma maintains better sharpness in the centre & in the image’s edges.

Conclusion (sharpness):

Both lenses have sầu good sharpness and contrast when you stop them down khổng lồ F4.0, & perform excellently at F5.6+. This is true for all focal lengths. Barring focus issues or camera shake you can be confident that your image will be decently sharp from corner lớn corner if you stick to these apertures – dramatically so at F5.6.

But how vì chưng these two perkhung at their maximum aperture? After all, you don’t buy an f/2.8 lens only to lớn use it at f/5.6+ vị you? Here the Tamron performs well at the wide kết thúc (17mm), but things get a bit fuzzy at the the telephoto end (50mm) of the zoom range.The Sigma showed almost exactly the opposite performance as the Tamron. At the wide over (17mm) the Sigma’s focussing was intermittently unreliable (more about this later), và even when AF worked correctly the result it was softer than the Tamron. At 50mm f/2.8 the Sigma came inlớn its own & delivered better sharpness và contrast.

Lens flare, vignetting, và chromatic aberration

Vignetting & lateral chromatic aberration (colour fringes) are no longer such a big worry, since cameras are getting increasingly good at correcting this automatically / in software. Even if your (older) DSLR camera doesn’t have this feature, Adobe Photosiêu thị and Lightroom vị a great job at fixing your photos after you download them (especially if you shoot RAW). With both these lenses chromatic aberrations were well controlled, and not something to worry about in real-world use.

More important is how well these lenses handle bright light (lượt thích the sun) hitting the lens from the front. This is something you sometimes can’t (or don’t want to) avoid, và if the lens screws up badly it’s almost impossible lớn fix the ruined result.