Archive for: EF 300 f/4L IS II

Patent: Canon EF 300mm f/4L IS & Others

Patent: Canon EF 300mm f/4L IS & Others

A patent for a new EF 300mm f/4L IS has appeared. Other optical formulas appearing in the patent are 24mm f/2.8 and 50mm f/1.3 with variable diffractive index elements which help correct some aberrations (thanks Keith).

Patent Publication No. 2015-28551 (Google Translated)

  • Published 2015.2.12
  • Filing date 2013.7.30

Example

Example Focal distance Fno. Half angle Image height Overall length of the lens BF
One 294.00 4.14 4.21 21.64 239.07 83.42
Two 24.48 2.86 41.47 21.64 92.00 38.00
Three 51.70 1.30 22.71 21.64 94.01 37.50
Four 294.00 4.14 4.21 21.64 240.00 82.95
Five 6.15 20.45 71.28 2.88 3.71 3.69 30.34 9.98 2.89 3.60 84.11 86.12 90.41 11.74 15.68 8.50
Six 293.97 4.14 4.21 21.64 239.98 85.34

Source: [Egami]

cr

23 Comments

New Lenses in January [CR1]

New Lenses in January [CR1]

Two f/4 Telephotos Coming
I’m told we can expect two new f/4 telephotos to be announced in January, 2013.

The first will be an EF 300 f/4L IS II, you can obviously expect better coatings, IS and a slightly lighter weight.

The second is said to be an EF 400 f/4L IS, no mention of it being a DO lens. With the price of the coming EF 200-400 f/4L IS 1.4x, mixed with the also expensive 400 f/4 DO IS, there is probably a big market for a 400 f/4 prime that is “affordable”.

cr

54 Comments

Patent: Canon EF 300 f/4L IS II

Patent: Canon EF 300 f/4L IS II

New Patent
Canon has filed a patent for the optical formula of a new EF 300 f/4L IS II.

Patent Publication No. 2012-159726

  • 2012.8.23 Release Date
  • 2011.2.1 filing date

Example 3

  • F = 300mm focal length
  • Fno. 4.0
  • Tele ratio 0.68
  • Inner Focus
  • φr = 68.8mm
  • φg1 = 67.8mm
  • φg2 = 70.2mm
Canon EF 300 f/4L IS at B&H Photo
+Continue Reading
15 Comments