Sigma 17-70mm f/2.8-4.5 DC

I bought this lens to combine it with my Sigma 18-200mm DC OS lens as a "travel kit". It is small and light for it's zoom range, as it should be since it is DC lens to be used on DLSRs with APS-C sensors.

Photos produced using this lens are sharp. The corners are not as sharp as the center but I expect that with a zoom with this range. Pixel peepers might see the somewhat softer corners, others won't. This isn't a Sigma "EX" lens but the photo quality is just about as good as an EX but it fortunately is lower in price than a comparable EX - it is an excellent value. This works as an excellent replacement for a kit lens and once one uses it, the kit lens will stay on the shelf.

Excellent value
Small and lightweight
Very good sharpness

No full time manual zoom (must use AF on-off switch)
A bit softer in corners than center (not unexpected for a zoom with this range)

Sigma 17-35mm f2,8-4 EX
Tokina 28-70mm f2.8 AT-X
Sigma 24-70mm f2.8 EX DG

None needed for this lens but I have used Sigma USA for other matters and their service is stellar.

Love the lens
Great value and very useable focal length

Sharp throughout the focal lengths
Great value
Very handy for walk around and holiday shoots
My most important lens for corportate events
Great Macro feature

Sigma famous coat peeling
Its not about wear and tear, its about bad workmanship.
Peeling renders your lens no resale value
[img]http://www.tommyleong.com/A989827/web1770_crop02.jpg[/img]

sigma 12-24 ( no problem with coating )
sigma 70-200 ( peeling )
Sigma70-300 ( no coating )

Horrid customer service
Totally unprofessional
Service technician would simply not turn up for work and refuse to meet customers
Counter receptionist attend to me
This is Sigma Singapore

Best bet for standard zoom on Canon crop cameras. The is in different class from the plastic Canon 18-55 that comes with 350D, though the latter is usable as well.
But the upgrade is well worth the $300+ IMHO.

I use it on 350D

Pro:
price, sharp, useful wide open all across, great contrast and color.

Neutral:
AF speed, no so fast on the long end. Reasonable build quality

Con:
Not as well made as Sigma EX (of course!). 70mm is still short for shooting fast moving baby faces.

This is definitely a keeper for me. Going to try out Tamron 18-250 next week. My fingers are crossed...

Wish it could be more than 70mm on the long end, 120 would be great.

Sigma 24-70 f2.8EX, was supposed to be sharp, but my copy was a dud, lemon, whatever you like to call it. Sent in for a fix, didn't improve much. But that 24-70 is surely a beauty! I just don't want to get rid of it even though it's a piece of junk...

Canon 18-55 is a few notch below this Sigma 17-70 - color is pale, detail is lacking, zoom range is less as well.

Canon 35-135 from an old film camera - The IQ is comparable to the 18-55, but much less attractive comparing to the Sigma. But Canon AF is better.

none needed

The 17-70 2.8-4 Macro lens from Sigma is a winner! This relatively low cost high quality lens may not come off your D-SLR for a long time.

At one pound, with a reversible petal hood and less than 4 inches in diameter this is a comfortable sized lens. 72mm filter threads, zoom lock, and Sigma's metal mount complete the technical high points, even if it still comes with a barely adequate style of lens cap.

Macro capabilities with this unit mean that it will focus on object at around 8" from the front of the lens throughout the zoom range. An internal focusing lens, the front threads do not rotate so it is perfect for ring flashes, Circular polarizers/effect filters, the included petal hood or a customized directional shades to name but a few items.

This is a sharp and nicely contrasty optic that focuses quickly across the zoom range and displays only minimal, if any, of the typical zoom optical issues. The wide end at 17mm with an APS-C sized sensor puts you at about 25mm focal length equivalent (depending upon camera, brand, etc) but that is a wide expanse for most anything other than a special need. If you tilt the camera it will of course distort and that can be exploited for enhancing perspective in a well controlled shot. The 70mm length at the other end bookends this as a fine trade off before reaching for a super zoom. Distant sports, reaching for that special nature shot or the like are not what this unit is about. Wider and longer than many of the standard kit zooms, with faster performance and better optical performance (MTF and real world examples) this is a prime contender for your main lens.

Only a constant aperture 2.8 in a narrower zoom range or a fixed focal length and at much greater weight and overall size penalty will provide better performance at the two extremes of this lens. These faster lens cost significantly more, not all are as well matched to digital sensor needs and many of these lens are designed to perform optimally only at one end or the other of their zoom range.

The DC designation from Sigma means that you can't use this jewel on your 35mm film camera without vignetting and if you shoot a full frame digital sensor, this is not the lens you want.

Focusing seems consistent and quick across the entire range of zoom, the coatings and optical performance are outstanding with flash, and of course the wide open 2.8 capability means that manual focusing is that much easier under lower light conditions.

Unit tested was provided by Sigma Corporation as a review sample. Testing and evaluation was performed with the 17-70mm lens mounted on both a SD-14 and a SD-10 D-SLR's.

Zoom Range
Bright Aperture
Internal Focus (fixed front threads for accessories)

DC, i.e. APS-C only lens. Love to have this range at anywhere near this price in a full frame capable lens.

No Dual-Focusing (no full time manual focus overide, have to throw the switch)

The lens cap issue.

Switchable only over

Several 18-50mm units and other zoom macros from Sigma. Also 24/28-70mm lens including constant 2.8 in various mounts on different brands of cameras.

A rather unusual combo of focal lengths and aperture's.

Not used for this product, but very satisfactory and prompt response from Sigma Corporation when required.

Was looking for an everyday lens with a useful zoom range. was considering 18-50 2.8 EX but saw a review of this and thought i'd take the plunge due to the extra zoom range. NO REGRETS. This lens is SHARP. The images only need a tiny touch of unsharp mask in PS to make them sing! The images are contrasty and full of colour. For the money, this is a TOP lens. Might not be quite as sharp as canon L glass but on an APS sensor camera, you won't notice the difference. Those of you with 1Ds, 5Ds etc might look elsewhere (you obviously have more money than me - lol!) but for most of us using APS sensors with less than 10MP, this lens is brilliant and, moe importantly, half the price of L glass. OK it's not the fastest lens in the world but for the majority of situations, it's absolutely fine and does go to f2.8 at 17mm.
The lens is well built and feels solid (without being overly heavy) and balances well on my 20D. The zoom ring is a little stiff but this may loosen up with use. The usual problem of sigma lenses applies here as well (minor though it is). The lens cap is woeful! sigma PLEASE PLEASE PLEASE start supplying centre pinch lens caps so we can keep lens hoods attached. Very simple but a massive oversight and a real pain.
In conclusion, if you own a digital camera with an APS sized sensor and need an everyday zoom lens, BUY THIS ONE and save the money you were going to spend on L glass to buy something else.

SHARP
well built
Price

Woeful lens cap
zoom ring a little stiff

Lots of different nikon lenses
Takumar lenses

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