This new lens does what many pros thought couldn’t be done – replace the previous L-series 28-70 f/2.8 lens with something even better. Extended coverage to an ultra-wide-angle 24mm makes it ideal for digital as well as film shooters, and the optics are even better than before with two Aspherical elements and a totally new UD glass element. It’s now sealed and gasketed against dust and moisture, and a new processing unit makes the AF faster than ever.

Internal Focusing
The internal focusing mechanism allows the front of the lens to remain stationary and to easily accommodate specialty filters, such as polarizing filters.

Two Aspherical Elements
A lens design incorporating elements ground so the curve of the surface does not describe an arc of a circle. Especially useful in reducing distortion in wide angle lenses.

UD Element
UD glass is one of the new technologies to open new possibilities to develop the zoom lenses with low weight and high optical performance. UD elements make it possible to correct chromatic aberrations whilst maintaining low weight.

Read more at Canon USA

Reviews

Canon EF 24-70mm f/2.8 L USM Lens Review by the-digital-picture.com

The Canon EF 24-70mm f/2.8 L USM Lens is an impressively high performing zoom lens. I regard it as one of the best general purpose lenses available and for the same reasons, it is one of the most-professionally-used Canon lenses. The 24-70 L is as good as it gets in this focal length range.

I think the Canon EF 24-70mm f/2.8 L USM Lens is one of the best Canon walk-around/all-purpose lenses made. Be sure to read the Canon EF 24-105mm f/4 L IS USM Lens review and, if you are using an EF-S capable body, the Canon EF-S 17-55mm f/2.8 IS USM Lens review before making your decision.

Canon 24-70mm f/2.8L review by luminous-landscape.com

Given that the old 28-70mm has long been considered a stellar performer — one of the most highly regarded mid-range fast zooms — to have it trumped so decisively by the new 24-70mm is quite a surprise. The timing of the release of this new lens is likely no accident, falling as it does simultaneous with the release of the ultra-high resolution Canon 1Ds. As I’ve noted elsewhere on this site and in my magazines reviews, the 1Ds’ resolution is so high that it is merciless in revealing the shortcoming of lenses. To extract maximum performance from a 1Ds only the finest lenses will do, and clearly Canon recognizes this with the release of the new 24-70mm f/2.8L zoom. Well done Canon!

Canon EF 24-70/2.8L USM Lens Review by photo.net

Producing a high quality high speed zoom lens that goes as wide as 24mm is challenging, but the “L” in “Canon 24-70L” assures you of professional quality images, rugged construction, and substantial weather-proofing. The 24mm wide end is wide enough to be dramatic, but the 70mm long end is not long enough for flattering portraits.

Links

Canon EF 24 – 70 mm F2.8 L USM lens MTF chart and news release by DPReview.com