Canon EF 24-70mm f/2.8L lens

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EF 24-70mm f/2.8L

Key Features
Maker: Canon
Image Stabilisation: No No
Silent AF Motor: Yes Yes
Short Back Focus: No No
Macro Capable: No No
Application: Pro Standard Zoom
Technical Data
Type: Zoom
Focal Length : 24-70mm
Frame Coverage: Full Frame
Aperture (max/min): f/2.8 - f/22
Construction: 13 groups / 16 elements
# Diaphragm blades: 8
Close focus distance: 1.25ft / 380mm
Physical
Max. Diameter: 3.3 in / 83.2 mm
Max. Length: 4.9 in / 123.5 mm
Weight: 2.1lbs / 950g
Filter diameter: 77mm
Accessories
Lens Hood: EW-83F
Angle of View
Diagonal: 84°-34°
History
Introduced: November 2002
Retail Info
MSRP US$ $2100


The EF 24-70mm f/2.8L is a professional EF mount wide-to-normal zoom lens. It was introduced by Canon in 2002 to replace the well-regarded 28-70mm f/2.8L.

Like its predecessor, this lens is often considered to have excellent contrast, color rendition and sharpness. However, some copies of the lens have also been reported to exhibit deficiencies and operational problems[1] not present in the older 28-70mm lens, including poor sharpness and/or chromatic aberration. Some reports suggest that the lens performs well only at certain apertures and focal lengths; others suggest that the lens back-focuses, primarily on DSLR cameras. The disparity between positive and negative reports about this lens indicates both manufacturing inconsistencies and subtle camera compatibility issues, as well as potential user error with the increase in sales of L-quality lenses amongst DSLR users.

The lens includes sealing against dust and water, although it is not waterproof. It also includes an 8-bladed curved diaphragm which remains nearly circular from f/2.8 to f/5.6. Characteristic of zoom lenses, it exhibits some barrel distortion at its shortest focal length.

Contents

[edit] Reverse zoom

An unusual aspect of the 24-70mm f/2.8L (and 28-70mm f/2.8L) is that its barrel extends as it zooms toward its shortest focal length. When used with the supplied lens hood, which attaches to a non-moving part of the lens, this extension results in a properly matched shade at every angle of view. Most zoom lens hoods are designed for only the widest angle of view, offering progressively inadequate shade at longer focal lengths.

This reverse zoom is illustrated with the following two pictures:

At the telephoto end (70 mm) the end of the lens is the most retracted providing the most shade protection from the lens hood. At the widest end (24 mm) the end of the lens is the most protruding providing the least shade protection fromt he lens hood.

[edit] References

  1. ^ http://www.fredmiranda.com/reviews/showproduct.php?product=5&sort=7&cat=27&page=1

[edit] See also

[edit] External links