Product Description

This high ratio zoom lens incorporates Sigma`s original OS (Optical Stabilizer) function and exclusively designed for digital SLR cameras. It is perfectly suitable for low light conditions, indoors, at dusk and telephoto range. SLD (Special Low Dispersion) glass and aspherical glass provide excellent correction for all types of aberrations. This lens has a minimum focusing distance of 45cm (17.7) throughout the entire zoom range and has a maximum magnification of 1:3.9. The inner focusing system is suitable for using a petal-type lens hood supplied and also circular polarizing filters.

Product Details

• Brand: Sigma
• Model: B000NOSCGM
• Released on: 2007-06-20
• Dimensions: 3.10" h x 3.10" w x 3.90" l, 1.34 pounds

Features

• 18-200mm high-zoom-ratio lens designed for Canon digital SLR cameras
• 2 Special Low Dispersion (SLD) glass elements and 2 hybrid aspherical lenses
• Lens coating reduces flare and ghost; 17.7-inch close focusing distance
• Inner focusing system is suitable for circular polarizing filters and lens hoods
• Measures 2.75 inches in diameter and 3.07 inches long; 1-year warranty

Amazon.com Product Description
The Sigma 18-200mm high-zoom-ratio lens is designed exclusively for Canon digital SLR cameras and is 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 correct for all types of aberrations, letting Sigma house the extended-range super-zoom lens in a compact and lightweight body that measures 70mm in diameter and 78.1mm long and weighs a mere 14.3 ounces. The new lens coating, meanwhile, reduces flare and ghost--a common problem shared by many digital cameras--while also creating an optimum color balance. Other details include a minimum focusing distance of 45cm (17.7) at all focal lengths, a high zoom ratio of 11:1, and a maximum magnification of 1:4.4.

The lens design incorporates an inner focusing system that prevents the front of the lens from rotating, making it particularly suitable for using circular polarizing filters and petal-shaped lens hoods. In addition, the overall length of the lens never changes during focusing, making the lens convenient to handle and easy to use. Finally, the lens's zoom lock switch eliminates "zoom creep" during transport--a convenient addition when traveling. The lens, which includes a metal mount, is backed by a one-year warranty.

Customer Reviews

Sigma got it right
We've been using this Sigma AF 18-200 lens for a couple of months now. Recently we compared the Sigma with Canon's 28-135mm image stabilized lens on a Canon 30D. We shot side by side photographs at 28mm & 135 mm both, set to ISO 100 with camera in Program mode. Our lenses were set to autofocus with image stabilization on.

The good news which I really didn't expect was to see both lenses produce images that were nearly identical-- I thought for sure Canon's optics would far surpass Sigma's. Color saturation, light exposure through the lens, and detail were indistinguishable. The autofocus worked equally well on both. Both weighed about the same and were about the same size. The Sigma has a 72mm diameter aperture which I liked (so does the Canon). Of course the Sigma is 18-200, and at this time Canon does not have a competing option in the same digital SLR lens class with image stabilization.

The only aspect of the Sigma that differed significantly from Canon's lens was the noise of Sigma's autofocus motor. Sigma produces noticeable motor noise, though it wasn't overly loud. Still if you were shooting in a spot where silence was critical such as a ceremony, it may become an issue but probably not. In comparison, the Canon autofocus motor is silent and fast every time.

Sigma places a locking mechanism on the lens barrel to eliminate any possibility of lens creep (lens extending when pointed down). I doubt this would be a problem with the Sigma anyway. The zoom ring is a little stiff, but not too stiff. The manual focus ring is designed to be used with AF set to off to avoid manipulating the motor when focusing.

The image stabilization works well allowing you to shoot lower light photos without a tripod. I was quite satisfied with Sigma's newest effort here.

I'd say this Sigma makes a great choice for amateur photographers like us looking for a single lens option on Canon digital SLR cameras. The only dissuading factor 'might' be the motor noise if you hope to match Canon's silent motor system. Until Canon produces the same class of lens at a competitive price, Sigma has this round sown up.

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UPDATE: "LENS CREEP" September 18, 2007
We did just notice the Sigma lens starting creep for the first time (extend while pointed down). So apparently while the zoom mechanism starts off stiff enough to hold the lens in position, over time it will loosen up enough to move on its own with gravity assisting. Still love the lens though.

Excellent solution for many Photographers.
This was shipped to my office yesterday, so I naturally had to play with it. I have an old Nikon D50, and had gotten use to the kit lens that was on it. This Sigma is CONSIDERABLY larger and heavier. I expected that of course, and maybe I'm just getting old, but IMO its a pretty hefty lens.

I bought this lens expressly for the Optical Stabilization, so that was the first thing I tested. My office has a logo painted on the far side, so I handheld, indoors, at 200mm and focused on one letter. The lens setting was f6.3 at 1/30 sec. Looking side by side at the OS and non-OS shot in the camera lcd screen, they looked almost identical.

However, puting them in Photoshop and blowing them up revealed a whole other story. The non-os picture was blurred - and no amount of sharpening in Photoshop could correct it.

The OS picture was sharp. I'm not easily impressed, but I was really surprised at how well it worked. When I enlarged it to 200 percent in Photoshop, it seemed to be a bit soft, so I applied a small bit of sharpening from the software - and ended up with a photo that looked like
it had been shot with a macro lens from 3 feet away on a tripod. It was outstanding.

I bought this lens for 2 reasons.

First I am a Realtor. All of my listings need indoor shots, and I stay away from flash if I can - natural light seems to create warm home interiors. Problem was, most of these shots ended up in the 1/8-1/15 range - so I packed a tripod around. This lens should be far more convenient.

Second, I am a photographer. I shoot a lot of weddings and reunions, and I often try to drag the shutter, especially in churches or large halls, where I want some ambient light to fill in the background. This lens will allow me to shoot all day at 1/15 sec. with a TTL flash, and create some nice balanced portraits without the background blur found in most of these sort of images from the slow shutter speed.

I have read in other reviews that this lens is slow. It is. If it were a straight lens with f6.3 at 200 mm, I wouldn't even consider it. However, the OS allows you to handhold safely at least another 2 fstops slower, so IMO, that makes up for the slow speed of the lens. Besides, it's ridiculous to compare a $500 lens to a $1700 lens in the first place.

The lens also has a bit of distortion. If you primarily shoot architecture, and don't want to correct all of your images, this isn't the lens for you.

I haven't noticed any lens creep yet, the zoom ring is pretty stiff, but that may change over time, and there is a lock, anyway.

One major complaint I have about this lens: the focus ring is prominent, and easy to grab. TOO easy to grab. Sigma warns against turning the focus ring when you are in autofocus mode, for fear of damaging the lens. I trained myself after about 15 minutes to keep my hand off of it, but I noticed that anyone that picked up the camera had a tendency to want to turn the focus ring, thinking it was the zoom ring. If you hand this lens to someone to take your picture, be sure to instruct them how to handle it, or risk damage to the lens.

The focus mechanism and OS are a bit noisy, but mostly because my ear is about 4 inches from the camera when it operates. I care very little about the noise factor.

Overall, this is a great lens. Inexpensive, will probably be on your camera exclusively, and allows you to handhold the camera in low light situations. I never got to test it against Nikon's version, but the difference in price made the choice easy. I recommend this lens highly.

3.5 Stars might be more accurate
First impressions after having the lens for 1 week, using with the Nikon D200 (upgraded from Nikon 24-120mm VR):

1. It is loud. When auto focusing or engaging the OS function, the lens makes a chirp sound. Doesn't really matter from a performance perspective, but it is annoying.

2. Auto focus in the dark takes longer than the 24-120mm Nikon. Not sure if this is the camera or the lens, but the lens just doesn't seem happy to do the nighttime auto focus.

3. Range is amazing. From full tele to full zoom, the photos look great.

4. OS stabilization seems to work just as well as the Nikon 24-120mm VR's did.

4. For just over 1/2 the price of the Nikon 18-200 VR, no matter how much quieter/faster the Nikon is, this seems like the better value for the buck.