Product Description

The Sigma 257-306 105mm F2.8 EX DG Macro lens for Canon SLR mount is very suitable for taking pictures in nature, while it uses natural light conditions or flash. The greater working distance of this lens is very advantageous when taking the picture of a flower among the branches or an insect. The narrow angle of view is a great aid for simplifying backgrounds and shallow depth of field makes it easier to handle the composition. This lens would have an equivalent field of view of a 178mm telephoto macro lens on a digital SLR camera. This new medium telephoto macro lens employs a new design concept for digital SLR cameras. Its power layout produces an excellent optical performance and also reduces flare and ghost. This lens is designed to reduce the influence of harmful light caused by reflections from the digital image sensor. A screw-in hood is included, for convenient use of circular polarizing filters. It is possible to attach a 77mm filter in front of the lens hood. This lens also incorporates a Dual Focus (DF) system that is designed to make the lens easy to hold during auto focusing. The large focus ring offers smooth and positive action whilst focusing manually. Weight - 16.1 ounces (457 grams)

Product Details

• Brand: Sigma
• Model: B0002P19XA
• Dimensions: 3.10" h x 4.00" w x 4.00" l, .99 pounds

Features

• Super Multi Coating reduces flare and ghosting that tends to occur when using digital SLR cameras
• High performance medium telephoto macro lens optimized for digital cameras
• Lens Construction - 11 Elements in 10 Groups
• 12.3 (31.3cm) Minimum Focusing Distance
• Dimensions - Diameter 2.9 x Length 3.8 (74x97.5mm)

Amazon.com Product Description
Optimized for Canon digital SLR cameras but also compatible with film SLR cameras, the Sigma 105mm f/2.8 medium telephoto lens allows a greater working distance between the lens and the subject, helping it excel in all shooting ranges. The increased working distance of the lens is ideal when taking the picture of a flower among several branches, or an insect on a leaf. The narrow angle of view helps simplify the background, while the shallow depth of field makes it easier to handle the composition. The lens also offers a super multi coating that reduces the flare and ghosting that tends to occur when using digital SLR cameras, helping create crisper, sharper photos. And thanks to the Dual Focus (DF) system, the lens is easy to hold during autofocusing, but also offers smooth and positive action should you choose to focus manually on images. Other features include a minimum aperture of f/45, a screw-in lens hood that supports the use of circular polarizing filters, and a minimum focusing distance of 12.3 inches. Offering a 35mm equivalent field of view of 178mm on a digital SLR camera, the lens carries a one-year warranty.

Specifications

• Focal length: 105mm
• Maximum aperture: f/2.8
• Lens construction: 11 elements in 10 groups
• Angle of view: 23.3 degrees
• Number of diaphragm blades: 8
• Minimum aperture: f/45
• Minimum focusing distance: 12.3 inches
• Maximum magnification: 1:1
• Filter size: 58mm
• Corresponding AF mounts: Canon
• Dimensions: 2.9 inches in diameter and 3.8 inches long
• Weight: 16.1 ounces
• Warranty: 1 year

Customer Reviews

Will satisfy your most basic needs for macrotography
Overall , the image quality is very good -- the sharpness is undeniably good. I'm no sucker for the techy terms but my most qualified review of the photos is -- I am very satisfied with the quality.

Downside - the AF motor is very slow. And MF is a bit mystery to me. I could not control the focusing during MF. Normally, I just move the switch to MF to lock on the subject and that's after focusing with the AF. I could not move the zoom range using MF (i must be doing something wrong ... or the instruction in the manual is not clear to me). The focusing motor moves back and forth most of the time before locking on to the subject -- that's what's making it slow -- so I always end up loosing the opportunity shot and have to wait for the subject to return for the shot.

A++++
Shipped on time.
Great Product.
Excellent price.
Will buy from them again and again.

Picture quality are good but make sure to have warranty
I bought this lens in December 2007 and just start to use it from this March. The picture quality is good but needs a lot of light and contrast for the AF to work.
In June, during an outing, one of the element (glass) fell out of it's holding socket and the lens would not retract to below 1:3.
Since I bought this lens in gray market, so that there's no warranty. I just open the lens and fix it myself, works fine.
However, the story did not end there. Just yesterday, during some test shots at home, the lens would not focus and the motor is trying but could not move. I switch to Manual but the focusing ring would not stay at M mode and I can turn the ring freely and it won't adjust the focus (in AF mode, the ring supposed to have resistence from the motor gear and you should not try to adjust manually).
If you are thinking of buying this lens, make sure to buy it with warranty or better yet extended warranty.