APS-C sized imageLenses that create APS-C sized image are designed for digital only. They cannot be used on cameras that have image sensor larger than the APS-C format. These lenses are not suitable for film cameras either. No Ultrasonic AFLenses with ultrasonic focusing mechanism tend to be quiter and faster than traditionally focusing lenses. One or more Low Dispersion lens element is usedLow Dispersion lens elements help to reduce chromatic aberration. Not stabilizedImage stabilization helps to reduce blur caused by hand shake, especially at high focal length or in low light situations. Image stabilization can give 1 to 3 stop advantage over none stabilized lens, based on the reciprocal rule. Metal mountCheaper lenses are usually equipped with plastic mount, while more expensive, professional lenses have metal mount. In general, metal mounts are more durable, and a good thing to have when lenses are changed a lot. When a camera is used mainly with one lens, the material of the lens mount is not that important. Internal FocusingInternally focusing lenses don't change their size while setting focus. The front lens is fixedThe fixed front lens is not rotating during zoom and/or focusing. This allows the photographer to use petal shaped lens hood. Fixed front lenses also make the use of polarization filters a lot easier. No drop-in filter supportDrop-in filters are used in those lenses where either the front lens is too large, or the field of view doesn't permit the use of traditional filters at the front of the lens. Usually bright tele and ultra-wide angle lenses support this filter type. |
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This high zoom ratio lens is exclusively designed for digital SLR cameras and capable of covering a wide range of focal lengths from wide-angle to telephoto. Two Special Low Dispersion (SLD) glass elements and two hybrid aspherical lenses offer the utmost correction for all types of aberrations, and enables this extended range super zoom lens to be housed in a compact and lightweight construction of 70mm (2.8 inches) diameter, and 78.1mm (3.1 inches) in length, and weighing just 405g/14.3oz. The new lens coating reduces flare and ghost, which is a common problem of digital cameras and also creates an optimum color balance. This lens has a minimum focusing distance of 45cm (17.7inches) at all focal lengths and has maximum magnification of 1:4.4.
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| Available mount(s) | Canon EF, Nikon F, Pentax K, Sony / Minolta A, Sigma |
| Application(s) | Portrait, Landscape, Wildlife, Architecture |
| Category(s) | Standard zoom, Tele zoom |
| Multiplier | 1.5× |
| Stabilizer | no |
| Focal length | 18 - 200 mm (11.1× zoom) |
| Lens construction | 15 elements in 13 groups |
| Angle of view |
35mm: N/A digital: 76.5-8.1° |
| Number of blades | 7 |
| Maximum aperture | wide: f/3.5 tele: f/6.3 |
| Minimum aperture | wide: f/22 tele: N/A |
| Minimum focusing distance | 45 cm |
| Magnification | 0.23× |
| Filter size | 62 mm |
| Size | ∅ 70 × 78.1 mm |
| Weight | 405 g |
| Notes |
At December 19, 2007, the Sigma announced a new version with built-in AF motor allowing autofocus with all Nikon APS-C DSLR cameras. The size of this model: 70 × 75,6 mm, and the weight is 395 g. |
| AF speed | 0.8 sec. (from close up to infinity) |
| AF sound | |
| Internal focusing | yes |
| Internal zoom | N/A |
| Fix front lens | yes |
| Mount type | metal |
| Weather sealed | N/A |
| Drop in filter | no |
| Ultrasonic AF | no |
| APS-C sized circle | yes |
| Low dispersion lens element | yes |
| Hard case | N/A |
| Soft case | N/A |
| Lens hood |
LH680-01 printable lens hood |
| Tripod adapter | N/A |
Jun 25, 2005
I disagree with the previous poster. I think this lens is pretty great.
The quality is exceptional for a lens of this price and range.
There seems to be a controversy regarding how focal lengths of lenses are measured; from what I've read, the lens does go to 200mm if measured at infinity.
In the real world, the lens takes fine pics as long as you have enough light. The size and weight is perfect for a walk-around lens. My Rebel XT with this lens (and the Hakuba hand grip) is a perfect fit, and feels great to carry around and shoot. To get better optical quality at this range, you would need to get a few lenses that each cost a lot more. There is nothing quite like this, except for Tamaron's 18-200, which I hear doesn't compare favorably to the Sigma.
It seems that Sigma has quality control issues, so I would buy
the lens from a local dealer that has a return policy. Test the lens, and if you don't think it's up to par, return it for another.
Jun 30, 2006
I got this lens a day before taking off for an eight day trip, and shot over 1800 photos with it. Though not the fastest lens out there, it did everything I wanted it to, both in the wide angle and the telephoto. I think I put it through a pretty thorough test over that week, and have these comments:
1. If I can only take one lens, this would be it.
2. I missed not having a macro feature, but I got close enough with the telephoto to make up for it in some cases.
3. The auto focus works fine in normal and bright lighting, but in dim lighting (like in a museum) it became confused and I used the manual focus option instead.
4. This is my third Sigma lens, and I haven't had any quality control problems with any of them.
5. I have no experience with high end Canon lenses for my Canon DSLR so I can't make a comparison, but I'm fully satisfied with the optics of this lens.
Excellent value and versatility.
Sep 25, 2005
3 stars because of:
1) soft corners at 18mm (f3.5)
2) vignetting at 18mm (f3.5)
3) lens creep (self extension of lens barrel while walking) if not retracted/lock at 18mm
This lens has the most useful range one can possibly have. It has become my only lens for short travelling trip when I don't want hassel of changing lens. I took only this lens with my Canon XT to Amsterdam (5days) without missing my other lenses at all. Here are some photos taken with this lens in my website:
http://www.theteh.com/html/london_street_.html
http://www.theteh.com/html/croatia.html
http://www.theteh.com/html/index1.html
For this price range (other than the Tamron 18-200) there is no other lenses that can compete!
Mar 13, 2007
This lens is not perfect, but for $350 dollars it is a great bargain!
I love my L lenses but I get frustrated having to switch lens all the time.
With this lens, I only have to carry my camera. Not the heavy camera bag. I love being able to use wide angle and then immediately switch to 200mm (300mm on the Rebel XT) within a second! The lens is light and is a pleasure to carry around all day.
It has a hard time focusing in low light so it is best to use outside when you have a decent amount of light.
I don't like that you cannot override automatic focus. That is one feature I really enjoy on my L lens. If the camera isn't focusing correctly you have to switch to manual before you can manually focus.
I am very surprised on how sharp the photos are. I wasn't expecting anything great in such a low priced lens. I am pleasantly surprised. I may be carrying around this lens a lot more than my 70-200 L and 17-40 L. I have missed many good shots due to the time it takes to change lenses. Also, every time you change a lens you take a chance of adding more specs (dust) to your photos.
It is kind of slow at the long end of the zoom range. (6.3 at 200mm) But, I don't mind it when there is a decent amount of light available.
It is an excellent walk around lens. It is so nice not to be carrying around a bag full of lens all day. My shoulder is thanking me already. Since it is so light, my neck doesn't hurt at the end of the day.
If I need the utmost quality, I will of course use my L lens. But, in the mean time this lens will suffice. I am having a lot of fun with it. I will post some shots soon.
I was kind of surprised that there are only 7 sample shots available here on Amazon. I promise I will add more so people can have a better representation of what this lens can do.
Oct 1, 2006
I just did a side by side comparison of landscape images between this lens and a canon 24-105L with a Digital Rebel XT. To my surprise there isn't much difference in image quality when you match the aperture and focal lengths. The Canon L series lens is faster at all focal lengths and has image stabilization, is sealed and comes with a lens hood, but costs about three times as much. The Sigma lens is slower to focus and noisier, but weighs quite a bit less and has almost twice the maximum focal length and is wider as well. So, if you are using a cropped image camera and have plenty of light, this lens ought to give good performance. If I had to choose between the two, I'd definitely take the Sigma for walking around or daylight landscape.