Tag Archives: EF 400mm f/4L DO IS

Canon Patent For EF 400mm f/4 IS DO Lens


Egami spotted a patent filed by Canon. The patent describes diffractive optical (DO) lens of the EF 400 f/4 IS. Canon lenses which feature the diffractive optical (DO) are smaller and lighter compared to the same focal length lenses but the price becomes generally higher when the lenses have optical formual for DO. The current lens has been aroundContinue Reading

Canon Filed Patent For New EF 400mm f/4L DO IS Lens

canon ef 400mm do patent

Egami has discovered a new  patent filed by Canon. Canon patent for the EF 400mm DO lens. Original article in Japanese for the new Canon patent can be read here. Below are the details for the EF 400mm f/4L DO IS lens patent details. Canon EF 400mm f/4L DO IS Lens Patent Patent Publication No. 2013-64858 2013.4.11 ReleaseContinue Reading