Canon EF-S 17-85mm f/4-5.6 IS USM Lens

I got this lens after some hesitation, partly because of its supposed "softness" and partly because of the lens working only on the aps-sized sensor cameras. I have been very glad that I decided to get it. The list price _is_ probably too high, but this is eBay, right? While I am amazed that some people will bid lenses and other things higher than mail-order retail prices, I was able to get this lens new from the eBay retail operation of one of the big New York stores for very much less than retail-- so much for its cost. As for softness-well, it produces images on a 20D that are sharper than the 35mm Kodachrome images from my best Nikkors, as digitized at 4000 dpi. It's not a copy lens, but the image stabilization is even better than that on the older IS lenses, and combined with the Canon high ISO abilities, this lens is a treat. By comparison with the little kit lens (18-55mm), it weighs a ton, but the total lens and camera package is well balanced and comfortable to use. Finally, the new 30D Canon shows that Canon is committed to the smaller sensor size for a little while longer, for sure.

I've shot about 2,500 pics with this lens - auto mode, manual mode, multiple custom settings, Image stabilization on and also off. I've enjoyed the lens and many great pictures.

The image stabilization is wonderful and when needed it DOES make a difference.
Comfortable in the hand although heavier than what I was used. Once you see your first set of pictures, the weight seems a very equitable trade off.
Sharp pictures, responsive autofocus, comfortable to manually focus.

Only complaint is that if you have 2 filters, don't back it out fully to 17mm unless you leave some room to crop. You will get shadowing in the corners that you'll want to get rid of.

This lens is a great carry around lens for Canon EOS 20D, 30D, Rebel XT and the other cameras to come that supports EF-S type lens. EF-S type lens only works with the cameras that have 1.6x crop sensor(with EF-S lens support), and the lens won't work with Canon's 5D, 1D series because they got either full frame or 1.3x crop sensor.

There has been other reviews that the lens is somewhat soft, and I agree that it is soft a bit - comparing it to "L" lens or non-zoom lens such as 50mm. But if you need versatility and light weight is what makes this lens so popular among 20D, 30D users. Plus it's got an amazing IS system on board. IS - Image Stabilization WORKS like a charm! If you haven't used one of these IS lens, you should check it out and if you have shaky hands and constantly getting blurred images due to your hand movement, this will definetely give you sharper image.

Many EF-S supporting cameras comes with 18-55mm lens as a kit. 17-85mm seems to focus better and faster. Also, USM (Ultra Sonic Motor) is virtually silent operation when autofocusing.

With 1.6x crop sensor, the lens will perform as 27.2mm-136mm. The image quality, sharpness, colors are very similar to Canon EF 28-135mm lens.

Pros:
5x zoom
Super-fast Ultrasonic Motor
Image Stabilization
Full-time manual focus ability
Circular aperture
Non-rotating front element
Excellent optical quality

Cons:
Size
Weight
Cost
Macro performance

The added telephoto range (5x zoom ratio, 28-135mm equivalent), super-fast Ultrasonic Motor and Image Stabilization were well worth the cost for me. I am constantly shooting in low light conditions, so Image Stabilization has been a lifesaver.

An important note on Image Stabilization: It will significantly improve your hand-held slow shutter shots (i.e. low light) ONLY if the subject is not moving. It lens can't keep your baby from flailing it's arms, but it can keep the image on the image sensor a little more stable and counteract the hand-shake that even the best photographers have.

The lens is large and heavy compared to the standard 18-55mm kit lens, but I prefer its more substantial feel (most of the time) but it will make you camera bag noticeably more snug. If your Camrea is a tight fit with the stock lens, it will probably not fit your bag with this lens - something worth planning for.

The components are all high quality (metal mount, aspheric elements etc.). This is simply a great general purpose with a broad range of abilities.

The one area in which I miss the stock lens is in macro photography, the stock 18-55mm has a very good close-focusing ability of just .9 feet whereas the 17-85mm is at 1.2 feet, with the higher telephoto focal length of 85mm the framing is virtually the same, but I prefer the 18-55mm for macros, it's just good - especially for the price.

The cost is considerable, especially if you are upgrading for the first time, but there are a few things to consider:
1] For $400 (or less), you can extend your camera body’s usefulness considerably. If you have a $1200 30D, that’s a sound investment.
2] If you are replacing a kit lens, they fetch $70-$100 on eBay.
3] If you think you want something that’s full frame compatible (meaning an EF and not a EF-S) for that “some day”, consider that Canon is still producing APS-C (EF-S) sized cameras by the millions, literally. MEANING the resale market will be quite strong for decades to come.

If you're looking for a good Pro-sumer choice, this is it; if you're looking for a professional Lens with awe-inspiring optics, look at spending a grand (or two) more (USD).