<H1>Canon Patent - 18-105mm f/4-5.6 Lens With Built-in Converter</H1>

Canon has patented a new design. It is a 18-105mm f/4-5.6 lens with a built-in teleconverter. However, when engaged, it makes the lens wider. At 18mm, the lens is f/4, but when the converter is engaged, it becomes a 15mm lens with an aperture of f/3.3.

This is an interesting lens concept but Canon has been experimenting with many new camera and lens designs in their laboratories for decades including one design with two built-in extenders. They have been awarded more patents than any other Japanese companies.

Normal use

• Focal length 18.40 37.44 104.0
• Aperture 4.00 4.64 5.89
• Half angle of view ω (degree) 36.59 20.04 7.48
• Image height 13.66 13.66 13.66 (APS-C)
• Lens total length 149.30 165.77 191.31

Wide-angle TC added

• Focal length 15.40
• Aperture 3.35
• Half angle of view ω (degree) 41.57
• Image height 13.66
• Lens total length 149.30