# Patent: 600 f/4 DO IS & 400 f/2.8 DO IS



## Canon Rumors Guy (May 23, 2012)

```
<div name="googleone_share_1" style="position:relative;z-index:5;float: right; /*margin: 70px 0 0 0;*/ top:70px; right:120px; width:0;"><g:plusone size="tall" count="1" href="http://www.canonrumors.com/2012/05/patent-600-f4-do-is-400-f4-do-is-ii/"></g:plusone></div><div id="fb_share_1" style="float: right; margin: 0 0px 0 10px;"><a name="fb_share" type="box_count" share_url="http://www.canonrumors.com/2012/05/patent-600-f4-do-is-400-f4-do-is-ii/" href="http://www.facebook.com/sharer.php">Share</a></div><div><script src="http://static.ak.fbcdn.net/connect.php/js/FB.Share" type="text/javascript"></script></div><div class="tweetmeme_button" style="float: right; margin-left: 10px; margin-bottom: 70px;"><a class="tm_button" rel="&style=normal&b=2" href="http://www.canonrumors.com/2012/05/patent-600-f4-do-is-400-f4-do-is-ii/"></a></div>
<strong>Patent Time!


</strong>More diffractive optic patents from Canon. This time, another 600 f/4 IS DO lens and a 400 f/2.8 DO IS.</p>
<p>With the cost of the new super telephotos from Canon, I can’t imagine what new DO lenses would cost.</p>
<p>Continue reading for the patent breakdown….</p>
<p><!--more--></p>
<p><strong>Patent Publication No. 2012-88427</strong></p>
<ul>
<li>2012.5.10 Release Date</li>
<li>2010.10.18 filing date</li>
</ul>
<p><strong>Example 1</strong></p>
<ul>
<li>Focal length f = 585.00mm</li>
<li>Fno 4.12</li>
<li>Image height 21.64mm</li>
<li>Length 468.50mm lens</li>
<li>BF 90.78mm</li>
<li>15 sheets of 9 group lens configuration</li>
<li>One aspherical surface a</li>
<li>2 UD glass sheet</li>
<li>One fluorite</li>
<li>A plane diffraction</li>
</ul>
<p><strong>Example 2</strong></p>
<ul>
<li>Focal length f = 391.86mm</li>
<li>Fno 2.88</li>
<li>Image height 21.64mm</li>
<li>Length 367.51mm lens</li>
<li>BF 50.01mm</li>
<li>Lens Construction 14 elements in 9 groups sheet</li>
<li>2 2 aspherical surface</li>
<li>1 UD glass sheet</li>
<li>One fluorite</li>
<li>A plane diffraction</li>
<li>Group 3 consists of positive and negative positive</li>
<li>Inner Focus (group 2)</li>
<li>Strengthen the refractive power of the front lens group, and to shorten the overall length, the sensitivity is increased, it is difficult to manufacture and assembly</li>
<li>The number of lens group at the end of the super-telephoto lens is determined by the balance of the total length and chromatic aberration</li>
<li>And shorten the length and reconcile, the correction of chromatic aberration, the number will increase</li>
<li>It is important to the length of each degree</li>
<li>Weight of the first lens group, 70% to 9 on the whole</li>
<li>Canon patents is reduced to three the first group</li>
<li>Aspherical and one eye in group 1 group, field curvature correction, the distortion</li>
<li>Diffractive optical element and the second two groups in the first group, the chromatic aberration correction</li>
</ul>
<p>Source: [<a href="http://egami.blog.so-net.ne.jp/2012-05-23" target="_blank">EG</a>]</p>
```


----------



## samkatz (May 23, 2012)

*Re: Patent: 600 f/4 DO IS & 400 f/4 DO IS II*

if only they could produce a DO lens in a cost effective way. Why "do" a version II when they hardly sell the original?


----------



## recon photography (May 23, 2012)

*Re: Patent: 600 f/4 DO IS & 400 f/4 DO IS II*

lol a recently made 600mm f4 do is how about $30,000


----------



## Frankie T Fotografia (May 23, 2012)

*Re: Patent: 600 f/4 DO IS & 400 f/4 DO IS II*

Crazy, today I was just wondering if they're going to update the 400 DO lens, and then I see this post about the patent for it. It's a pretty old lens and could use an update. I believe the IS on the old lens only offers 2 stops of image stabilization, so it would be great for them to upgrade it to at least 4 stops of image stabilization. Also if they can make it even lighter, and have better contrast wide open, then I think they'll have a winner in their hands. I just hope it's not as pricey as the recent batch of Canon's Super Telephotos :-\


----------



## CatfishSoupFTW (May 23, 2012)

*Re: Patent: 600 f/4 DO IS & 400 f/4 DO IS II*

maybe canon wants everyone to secretly sell their souls for their lenses... 0__o


----------



## Canon Rumors Guy (May 23, 2012)

Corrected the errors in the original post.


----------



## Daniel Flather (May 23, 2012)

The 600 v2.0 is still not on the sales floor as of today.


----------



## GMCPhotographics (May 23, 2012)

I think if Canon could find a way to keep their lens purchase price at a more reasonable level and can correct the lack of contrast and lower sharpness that DO tech causes, then I think Canon would have a winner on their hands.

A 400m f2.8 DO that's 1/3 of the weight but carries the same IQ that the L version offers can only be good.


----------



## RLPhoto (May 23, 2012)

With all these DO patents, We can expect an major unveiling of an entire new Canon DO line-up sometime in the future. Its would be a nice to have an more affordable versions of the larger longer lenses 300mms and up.


----------



## FarQinell (May 23, 2012)

I wonder why the "design" focal length of BOTH are less rather than slightly higher than nominal?

They had better do a better job on these lenses than they did on the 400/4.

Maybe Canon have gone as far as they can with reducing weights of conventional super telephotos and any further weight reductions will have to be by way of DO. Risky expensive strategy!

Note to Canon:
Produce a conventional design 500/5.6 prime coming in at under 5000USD and 2.5kg. It would be a best seller for you!


----------



## dlleno (May 23, 2012)

RLPhoto said:


> With all these DO patents, We can expect an major unveiling of an entire new Canon DO line-up sometime in the future. Its would be a nice to have an more affordable versions of the larger longer lenses 300mms and up.



+1 on that. I wonder if 600mm f/4 DO would represent an alternative to the 500mm f/4, for wildlife -- in terms of weight and hand-holdability implied by the shorter physical length. ... and what would the price be, and how would Canon position this one along side the today's 600mm. And would it play well with a 1.4x....

All that aside, a shorter/lighter/cheeper 600mm f/4 would be wonderful, and give wildlife folks a new option.


----------

