July 23, 2014, 04:20:32 AM

Author Topic: Patent: More DO Supertelephoto Lenses  (Read 5583 times)

Canon Rumors

  • Administrator
  • Canon EF 300mm f/2.8L IS II
  • *****
  • Posts: 2526
    • View Profile
    • Canon Rumors
Patent: More DO Supertelephoto Lenses
« on: May 17, 2013, 09:34:18 AM »

DO appears to still be alive

More patents for large Canon DO lenses. The one of note is the 500 f/5.6, a lens that would be a very solid follow-up to the EF 400 f/4 DO IS.


We’ve seen a lot of these patents in the past, and none of them have ever come to market. It is good to see R&D is still going into DO technology, as I really enjoy the 400 DO.


50056dopatent


Source: [EG] via [NL]


cr


canonrumors.com

canon rumors FORUM

Patent: More DO Supertelephoto Lenses
« on: May 17, 2013, 09:34:18 AM »

edknuff

  • SX50 HS
  • **
  • Posts: 3
    • View Profile
Re: Patent: More DO Supertelephoto Lenses
« Reply #1 on: May 17, 2013, 11:50:50 AM »
Greetings from So Cal.
I've never heard of a "DO" lens.  Could you explain what it is and its purpose?
Thank you,
Ed

Schruminator

  • Rebel SL1
  • ***
  • Posts: 87
  • I'm just kidding, seriously.
    • View Profile
    • M Schrum Photography
Re: Patent: More DO Supertelephoto Lenses
« Reply #2 on: May 17, 2013, 12:00:14 PM »
You can check out the links below for a bit more information on DO lenses. On the first link, scroll down a ways for a quick diagram.

http://www.usa.canon.com/cusa/consumer/standard_display/Lens_Advantage_Perf

http://www.canon.com/premium-lib/movie/t005/

http://www.cambridgeincolour.com/forums/thread1972.htm

Hopefully that helps some.
« Last Edit: May 17, 2013, 12:04:38 PM by Schruminator »
5D III | 14 2.8 L | 24 1.4 II L | 35 1.4 L | 50 1.2 L | 85 1.2 II L | 24-70 2.8 II L | 70-200 2.8 IS II L | 40 2.8 | 1.4x Mk. II T.C. | M Schrum Photography

viggen61

  • EOS M2
  • ****
  • Posts: 158
    • View Profile
Re: Patent: More DO Supertelephoto Lenses
« Reply #3 on: May 17, 2013, 01:54:04 PM »
Greetings from So Cal.
I've never heard of a "DO" lens.  Could you explain what it is and its purpose?
Thank you,
Ed
"DO" stands for "Diffractive Optics". Canon use it as a method to make lenses smaller and lighter. They currently offer two "Green ring" lenses: the EF 400mm f/4 DO IS USM ($6,469 list), and the 70-300 f/4.5-5.6 DO IS USM ($1,399).
Canon 7D

dolina

  • 1D Mark IV
  • ******
  • Posts: 968
    • View Profile
Re: Patent: More DO Supertelephoto Lenses
« Reply #4 on: May 19, 2013, 03:49:29 AM »
By my reckoning a 500/5.6 DO IS would weigh about as much as a 400/5.6 (2-3lbs) but would sell easily sell for 500/4.0 IS II prices.
Visit my Flickr, Facebook & 500px and see my photos. :)

Mt Spokane Photography

  • Canon EF 600mm f/4L IS II
  • ********
  • Posts: 8229
    • View Profile
Re: Patent: More DO Supertelephoto Lenses
« Reply #5 on: May 20, 2013, 11:12:01 AM »
Smaller diameter, shorter length, and no fluorite crystal, and less manufacturing difficulties using aspherical and diffractive elements instead.  The obvious goal is to produce a lens that is smaller and more affordable than todays super high priced big white lenses, but expect that they will be in the 3500-5000 range at least.
 
I could certainly go for a small 500mm f/5.6 telephoto if I could afford it.

 
Here are a couple of excerpts of the translated wording. (I believe the word sheets refers to lens elements)

 
 "EFFECT OF THE INVENTION


[Effect of the Invention]
 [0012]
 according to the present invention -- manufacture -- an easy, small, and lightweight optical system and imaging device can be provided.  "
 
 
"It is preferable that the diffraction optical element DOE which has at least 1 diffracted-light faculty D is provided by the 1st lens group L1. By providing the diffraction optical element DOE, it becomes easy to correct a chromatic aberration, without increasing lens number of sheets, and even if it does not use anomalous dispersion glass, such as fluorite whose specific gravity is comparatively heavy, correction of a chromatic aberration is attained. At this time, since the further weight saving can be attained, it is preferable.  "

Tom W

  • Power Shot G16
  • **
  • Posts: 38
    • View Profile
Re: Patent: More DO Supertelephoto Lenses
« Reply #6 on: May 20, 2013, 12:51:27 PM »
I owned the 70-300 DO lens for a couple of years. While it wasn't a bad lens, the DO did take a bit of a toll on IQ, particularly in situations where lens flare was likely (strong light source striking the front element). Bokeh was a little awkward/choppy at times also. I understand that the 400/4 DO is a very good lens.

I'd like to see a refinement in the DO design that would produce an even better optical quality. The light weight and relatively small package makes a strong selling point for this technology.

canon rumors FORUM

Re: Patent: More DO Supertelephoto Lenses
« Reply #6 on: May 20, 2013, 12:51:27 PM »

Mt Spokane Photography

  • Canon EF 600mm f/4L IS II
  • ********
  • Posts: 8229
    • View Profile
Re: Patent: More DO Supertelephoto Lenses
« Reply #7 on: May 20, 2013, 07:33:56 PM »
I owned the 70-300 DO lens for a couple of years. While it wasn't a bad lens, the DO did take a bit of a toll on IQ, particularly in situations where lens flare was likely (strong light source striking the front element). Bokeh was a little awkward/choppy at times also. I understand that the 400/4 DO is a very good lens.

I'd like to see a refinement in the DO design that would produce an even better optical quality. The light weight and relatively small package makes a strong selling point for this technology.

Canon has a number of recent patents for new DO lens technology, but it seems to be exceedingly difficult to manufacture.  It is based on small particles immersed in a resin compound.  The resultant radial dispersion of particles can produce a superior lens element that varies its properties radially.  The issue is getting the spacing of the particles right in a consistent way, and that may never happen.  You can't just pour a powder in a vat of resin and mold a bunch of identical lens elements.  Every one will be different.
 
They did not specifically mention this technology in the patent, but did talk about a resin compound, so its in there somewhere.

jrista

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 3707
  • POTATO
    • View Profile
    • Nature Photography
Re: Patent: More DO Supertelephoto Lenses
« Reply #8 on: May 20, 2013, 08:11:08 PM »
I owned the 70-300 DO lens for a couple of years. While it wasn't a bad lens, the DO did take a bit of a toll on IQ, particularly in situations where lens flare was likely (strong light source striking the front element). Bokeh was a little awkward/choppy at times also. I understand that the 400/4 DO is a very good lens.

I'd like to see a refinement in the DO design that would produce an even better optical quality. The light weight and relatively small package makes a strong selling point for this technology.

Canon has a number of recent patents for new DO lens technology, but it seems to be exceedingly difficult to manufacture.  It is based on small particles immersed in a resin compound.  The resultant radial dispersion of particles can produce a superior lens element that varies its properties radially.  The issue is getting the spacing of the particles right in a consistent way, and that may never happen.  You can't just pour a powder in a vat of resin and mold a bunch of identical lens elements.  Every one will be different.
 
They did not specifically mention this technology in the patent, but did talk about a resin compound, so its in there somewhere.

It may not be as easy as simply mixing "power" with resin an getting ideal results every time...but I would be willing to bet they could mix lightly charged particles with slightly varying charges in resin, and before it cools use a magnetic or electromagnetic field to disperse them properly.
My Photography
Current Gear: Canon 7D | Canon EF 600mm f/4 L IS II | EF 100-400mm f/4.5-5.6 L IS | EF 16-35mm f/2.8 L | EF 100mm f/2.8 Macro | 50mm f/1.4
New Gear List: Canon 5D III/7D II | Canon EF 300mm f/2.8 L II

Mt Spokane Photography

  • Canon EF 600mm f/4L IS II
  • ********
  • Posts: 8229
    • View Profile
Re: Patent: More DO Supertelephoto Lenses
« Reply #9 on: May 20, 2013, 11:25:41 PM »
I owned the 70-300 DO lens for a couple of years. While it wasn't a bad lens, the DO did take a bit of a toll on IQ, particularly in situations where lens flare was likely (strong light source striking the front element). Bokeh was a little awkward/choppy at times also. I understand that the 400/4 DO is a very good lens.

I'd like to see a refinement in the DO design that would produce an even better optical quality. The light weight and relatively small package makes a strong selling point for this technology.

Canon has a number of recent patents for new DO lens technology, but it seems to be exceedingly difficult to manufacture.  It is based on small particles immersed in a resin compound.  The resultant radial dispersion of particles can produce a superior lens element that varies its properties radially.  The issue is getting the spacing of the particles right in a consistent way, and that may never happen.  You can't just pour a powder in a vat of resin and mold a bunch of identical lens elements.  Every one will be different.
 
They did not specifically mention this technology in the patent, but did talk about a resin compound, so its in there somewhere.

It may not be as easy as simply mixing "power" with resin an getting ideal results every time...but I would be willing to bet they could mix lightly charged particles with slightly varying charges in resin, and before it cools use a magnetic or electromagnetic field to disperse them properly.
Actually, Canon does give some information about their process in the patents for the diffractive lens.
I do not think that the particles are magnetic.
 
"DESCRIPTION OF THE EMBODIMENTS

[0022] This embodiment provides an optical system with a radial gradient-index optical element having a refractive index that changes in a direction perpendicular to an optical axis in a medium. In comparison with an axial gradient-index optical element having a refractive index that changes in an optical axis direction in the medium, the medium of the radial gradient-index optical element has a refractive power caused by refractive index distribution, So the radial gradient-index optical element has an advantage of correcting the chromatic aberration by setting a proper refractive index distribution.

[0023] In the gradient-index optical element, when a refractive index distribution for each wavelength can be independently controlled, the chromatic aberrations for the d-line, the C-line, the F-line, and the g-line can be simultaneously corrected. However, it is difficult to independently control a refractive index distribution for each wavelength when the gradient-index optical element is actually produced.

[0024] Accordingly, this embodiment properly controls a wavelength dispersion characteristic of the gradient-index optical element, and thereby realizes an optical element that has an effect of correcting the chromatic aberration.

[0025] An ion exchange method, a sol-gel method, and three-dimensional printing are known as a manufacturing method of a gradient-index optical element. These methods can distribute a refractive index by gradually changing a composition ratio of the gradient-index optical element for each location. In this gradient-index optical element, this embodiment properly sets a refractive index distribution so that the following conditional expressions can be satisfied, and the chromatic aberrations for four wavelengths can be well corrected. "
 
However, as with all patents, its easier said than done, so I'm not overly optimistic about seeing a low cost DO implementation soon.

RLPhoto

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 3263
  • Gear doesn't matter, Just a Matter of Convenience.
    • View Profile
    • My Portfolio
Re: Patent: More DO Supertelephoto Lenses
« Reply #10 on: May 20, 2013, 11:37:03 PM »
I think canon will just release a whole line-up of DO lenses at one time when we least expect it...  :o

jrista

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 3707
  • POTATO
    • View Profile
    • Nature Photography
Re: Patent: More DO Supertelephoto Lenses
« Reply #11 on: May 21, 2013, 09:35:13 AM »
However, as with all patents, its easier said than done, so I'm not overly optimistic about seeing a low cost DO implementation soon.

Very true...however the entire optical engineering world told Canon that making a viable diffractive grating lens was impossible, and yet, Canon persisted and eventually succeeded. ;P I suspect Canon will figure out a way to make a diffractive particle dispersion lens at some point as well...or something else sufficiently superior to their grating lenses as to solve the IQ problems, and still support the construction of smaller, lighter weight lenses for long focal lengths. Canon is nothing if not persistent.
My Photography
Current Gear: Canon 7D | Canon EF 600mm f/4 L IS II | EF 100-400mm f/4.5-5.6 L IS | EF 16-35mm f/2.8 L | EF 100mm f/2.8 Macro | 50mm f/1.4
New Gear List: Canon 5D III/7D II | Canon EF 300mm f/2.8 L II

RGF

  • 1D X
  • *******
  • Posts: 1229
  • How you relate to the issue, is the issue.
    • View Profile
Re: Patent: More DO Supertelephoto Lenses
« Reply #12 on: May 23, 2013, 11:33:20 PM »
Wonder how many of canon 's patent make it to the market place vs simply are defensive and hold IP defensive space

canon rumors FORUM

Re: Patent: More DO Supertelephoto Lenses
« Reply #12 on: May 23, 2013, 11:33:20 PM »