In August, Canon announced the upcoming release of three new lenses - the EF 300mm f/2.8L IS II USM, EF 400mm f/2.8L IS II USM and EF 8-15mm f/4L Fisheye USM.

While the latter was expected to be released in January 2011, the 300mm and 400mm model had been announced with a December 2010 release date. However, Canon has now been forced to cancel those plans. In a statement released this week, the firm says that it "has now delayed the introduction of these lenses due to some adjustments in the manufacturing process."

Canon now expects the lenses to be released in March 2011. "Canon would like to apologise to any customers who will be inconvenienced by these delays," the statement reads.

The EF 300mm f/2.8L IS II USM and EF 400mm f/2.8L IS II USM are designed for nature, wildlife and sports photographers. "Each features a completely redesigned optical system and the latest iteration of Canon’s original Image Stabilizer technology," said the imaging company in August.

The two lenses feature a magnesium allow construction and titanium components, while offering, respectively, a 15% and 8% weight reduction over their predecessors. They both use 16 elements in 12 groups and features "high performance fluorite lens elements that correct chromatic aberration to deliver high resolution and high contrast shots of the best possible quality," says Canon.

The lenses' front and rear elements also use fluorine coating to repel dust, dirt and water "keeping the front element free of water marks and smearing by ensuring water runs off the lens quickly," according to Canon.

The new Image Stabilizer system gives photographers a four-stop advantage for "greater image quality during handheld shooting". The lenses also feature a fast and quiet autofocusing system and a new high-speed CPU, all in a new design layout.

The EF 300mm f/2.8L IS II USM is priced at £7500 and the EF 400mm f/2.8L IS II USM  at £11,500.

The EF 8-15mm f/4 Fisheye USM, when paired with Canon's full frame digital SLRs, offers photographers a choice between the two image formats. However, when coupled with a APS-C or APS-H sensors, the lens only offers full-frame fisheye images.

The lens uses 14 elements in 11 groups, including one aspherical and one Ultra-Low Dispersion element to correct chromatic aberration, says Canon. It also features a Super Spectra Coating to prevent ghosting and flares, as well as a Fluorine Coating to repel water, dust and dirt from the front and rear lens elements.

When released in March 2011, the lens will retail at £1500.

For more details, visit www.canon.co.uk.