Product Description

AF is super-fast and silent with a ring-type USM, and it focuses down to 4.6 feet without rotating the front element. A new zoom lock button keeps the lens safe and secure when not in use or used at the wide angle.

Product Details

• Brand: Canon
• Model: 9321A002
• Dimensions: 5.20" h x 5.40" w x 7.20" l, 4.00 pounds

Features

• Ultra-compact 70-300mm telephoto zoom lens with f/4.5 to 5.6 maximum aperture
• Incorporates Canon's Image Stabilization (IS) technology for low-light shooting
• Super-fast and silent autofocus with ring-type USM; 4.6-foot close focus distance
• Optimized to suppress ghosting and flaring; zoom lock button keeps lens secure
• Measures 3 inches in diameter and 5.6 inches long; weighs 4.9 foot; 1-year warranty

Amazon.com Product Description
Canon raises the stakes for professional photography with its EF 70-300mm f/4.5-5.6 DO IS USM telephoto lens with image stabilization. Thanks to a new triple-layered diffractive optical element (DO), this 70-300mm lens is less than 4 inches (10 cm) long. It can focus down to 4.6 feet (without rotating the front element) and a new zoom lock button keeps the lens safe and secure when not in use or used at the wide angle. A virtually silent ultra-sonic motor (USM) gives the lens extremely fast autofocus. The lens also includes Canon's Image Stabilization technology to dramatically reduce camera shake, compensating for approximately three stops in shutter speed without any perceptible increase in image blur. It's a great choice for professional photojournalists and serious advanced amateurs who need to contain the size and weight of equipment carried.

DO Elements
Use of the new three-layer DO lens drastically reduces the overall length and weight of the lens system increasing the refractive power of each lens element and reducing the spaces between elements. It's approximately 26 percent shorter and 36 percent lighter than any lens of comparable specifications.

Zoom lock
The EF 70-300mm lens features a zoom ring locking mechanism, locking the lens at its shortest total length. This helps to protect the lens from potential damage by preventing the zoom elements extending under their own weight, which might otherwise occur when the lens is mounted to a camera that hangs from a neck or shoulder strap.

Image Stabilization
The lens incorporates Canon's Image Stabilization (IS) technology, compensating for approximately three stops without any perceptible increase in image blur when shooting static subjects or panning. This increases the range of circumstances in which hand-held photography is possible, limiting the need to carry a tripod.

Fast AF
A rear focusing ring type USM, high-speed CPU and new AF algorithms combine to give the lens extremely fast auto-focusing. The ring-type ultrasonic motor (USM) converts ultrasonic vibrational energy into rotational force to deliver high-speed, high-precision, super efficient and virtually noiseless auto focusing, with good holding torque for rapid response and accurate stopping. Full-time manual override is featured, removing the possibility of damage to the autofocus mechanism during manual focus. The lens has a minimum focusing distance of just 1.4m throughout the entire zoom range.

Ready for Digital Photography
The lens shape and coatings have been optimized to suppress ghosting and flaring, making this lens ideal for use with digital cameras that are more susceptible to reflections off the recording media than are film cameras.

Working with EOS
The drive pattern of the lens is tailored to specifically match that of the latest EOS range, extracting maximum benefit from the lens' speed advantage. The lens comes with a case LP1116 and an exclusive hood ET-65B for shading against unwanted direct light.

Customer Reviews

Great telephoto for outdoor shooting.
Watch Video Here: http://www.amazon.com/review/R1LY6FU6TXCFXV Canon EF 70-300mm f/4.5-5.6 DO IS USM Lens for Canon EOS Cameras

Excellent lens with a 40D
Paired this lens up with a 40D. After several months of heavy use:

Highs:
Solid feel, well built. Works very well - even at 12000ft+ and well below freezing, always ready for use straight out of the bag on long hikes.
Easy to focus precisely.
Zoom stays in place even when pointed vertically - up or down - without the lock button. I may be lucky and have a good build of the lens.
Excellent resolution in shots.
Small - easy to pack and take on hiking trips. Got many shots would otherwise have missed.
Can focus in auto mode as ring is decoupled from actual motor.

Comments:
Found it very hard to reproduce the artifacts mentioned in reviews - basically had to point it through grills close to the lens with aperture wide open.
Tried pointing into the sun (WITHOUT looking in viewfinder) and glare was not apparent.

Lows/tips:
Contrast not as good as a fixed lens or 70-200L .
Most shots Good to Excellent but some had to be Photoshopped to recover contrast.
Recommend shooting raw in dusty/cloudy conditions with lot of ambient light around, or when lens wide open.
f4.5 aperture could be wider for my ideal lens. The f4 of the non DO model makes some difference.
Costs a lot.

I agonized over the cost, but after trying it and it's lower cost non DO rival I chose this as I do a lot of traveling. Both packing down and solid build are important. Apart from contrast, the look of the resulting photos is good to excellent, and shooting in raw for challenging hazy environments brings out the best. The resolution/sharpness is excellent - can leave it at f5.6 and shoot without caring - good to capture those spontaneous moments.

A 70-300 DO and a 40D make for an excellent travel set.

Excellent lens - caution: the lens hood comes with it
Excellent quality and fast lens.
Heavier than I expected.
Note, when ordering this lens DON'T also order the Canon ET-65B Lens Hood because it comes with the lens.