Canon Blue Spectrum Refractive Optics Explained

Canon introduced Blue Spectrum Refractive Optics technology with the EF 35mm f/1.4L II lens last year. I expect more EF lens coming this year will have that technology. The one lens I am most interested in is the EF 600mm f/4 DO BR lens, which made its debut at the Canon Expo 2015 Show in New York City.

New Canon Patent - EF 16-40mm f/4 Lens

Canon EF 17-40mm f/4L Lens

Egami has uncovered another Canon patent for the EF 16-40mm f/4 lens. The venerable EF 17-40mm f/4L could be in for a replacement in 2016. Canon has been making their new, shorter focal length 'L' lens bigger, case in point - the new EF 35mm f/1.4L II. The expected EF 16-35mm f/2.8L III, which is out in the field for testing, may also be slightly bigger than the current model.

Patent Publication No. 2015-206976 (Google Translated)

•     Published 2015.11.19
•     Filing date 2014.4.23
•     Zoom ratio 2.36
•     Focal length 16.48 24.40 38.90
•     F-number 4.12 4.12 4.12
•     Half angle (in degrees) 52.70 41.56 29.08
•     Image height 21.64
•     Overall length of the lens 177.74 162.40 159.73
•     BF 38.00 45.51 63.40

There has been a series of new patents discovered this year. Canon will be announcing more EF and EF-S lens in 2016.

Canon EF 35mm f/1.4L Mark II Lens TearDown

Canon EF 35mm f/1.4L II lens

The guys at LensRentals.com had taken apart the recently announced Canon EF 35mm f/1.4L II lens. They are most impressed by its build quality. Take a look at a review of the lens here. The same guys have also taken apart the Canon EOS-5Ds camera for an inspection. Take a look at this post.


Read the full article here. Below is an excerpt from their review :

    …This lens is massively over-engineered compared to any other prime we’ve ever disassembled. It’s built like a tank where it counts; on the inside. Moving parts are huge and robust. Six big screws are used in locations where 3 smalls screws are common in other lenses. Heavy roller bearings move the focusing group, it doesn’t slide on little nylon collars.

    …If I had to summarize the mechanical design of this lens, I would say simply that no expense was spared, no corner was cut.

    Sometimes things are expensive because they’re worth it. Sometimes they’re heavy because they’re so solidly constructed. This is one of those times.