Canon EF 100-400 f/4-5.6L IS Patent Pending

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<div id="attachment_7187" class="wp-caption aligncenter" style="width: 327px"><img class="size-full wp-image-7187" title="100400patentnew" src="http://www.canonrumors.com/wp-content/uploads/2011/09/100400patentnew.png" alt="" width="317" height="206" /><p class="wp-caption-text">New 100-400 f/4-5.6L IS Optical Design</p></div>
<strong>New 100-400 f/4-5.6L IS in the pipeline?

</strong>A pending patent has shown up showing a new 100-400 optical design. This new design seems to suggest better optical performance as well as starting at f/4.</p>
<div id="attachment_7188" class="wp-caption aligncenter" style="width: 410px"><img class="size-full wp-image-7188" title="100400patentoriginal" src="http://www.canonrumors.com/wp-content/uploads/2011/09/100400patentoriginal.png" alt="" width="400" height="270" /><p class="wp-caption-text">Current 100-400 f/4.5-5.6L IS Optical Design</p></div>
<p><strong>Patent Publication No. 2011-180218</strong></p>
<ul>
<li>2011.9.15 Release Date</li>
<li>Filing date 2010.2.26</li>
</ul>
<p><strong>Example 1</strong></p>
<ul>
<li>Focal length f = 72.20 – 135.00 – 290.00mm</li>
<li>Fno = 4.20 – 4.67 – 5.86</li>
<li>Half angle of 16.68 – 9.10 – 4.27 °</li>
<li>Image height 21.64mm</li>
<li>Lens length 185.20 – 214.53 – 239.20mm</li>
<li>Back Focus 46.74 – 47.82 – 57.41mm</li>
<li>4.02x zoom ratio</li>
<li>Group 6 for each group</li>
<li>Positive and negative polarity positive or negative group configuration</li>
</ul>
<p><strong>Example 2</strong></p>
<ul>
<li>Focal length f = 102.20 – 200.00 – 390.01mm</li>
<li>Fno = 4.10 – 4.55 – 5.90</li>
<li>Half angle of 11.95 – 6.17 – 3.18 °</li>
<li>Image height 21.64mm</li>
<li>Lens length 228.18 – 258.83 – 288.12mm</li>
<li>Back Focus 51.23 – 54.42 – 69.84mm</li>
<li>3.82x zoom ratio</li>
<li>Group 6 for each group</li>
<li>Positive and negative polarity positive or negative group configuration</li>
</ul>
<p><strong>Example 3</strong></p>
<ul>
<li>Focal length f = 100.20 – 135.10 – 290.19mm</li>
<li>Fno = 4.36 – 4.47 – 5.81</li>
<li>Half angle of 12.18 – 9.10 – 4.26 °</li>
<li>Image height 21.64mm</li>
<li>Lens length 184.66 – 198.82 – 244.82mm</li>
<li>Back Focus 42.53 – 46.68 – 63.07mm</li>
<li>2.90x zoom ratio</li>
<li>5 groups, each group</li>
<li>Positive and negative group of negative polarity configuration</li>
<li>Positive-lead type zoom lens</li>
<li>High zoom ratio can be easily realized</li>
<li>Rear Focus</li>
<li>Can be miniaturized</li>
<li>Easy full-time manual</li>
<li>Suppressing the fluctuation of spherical aberration</li>
<li>Upon zooming, if you move from behind the eyes, counting the two groups, the greater the variation of spherical aberration in the focusing</li>
<li>On-axis beam angle θ the following equation:</li>
<li>θ = AISN (1 / 2 * Fno)</li>
<li>Spherical aberration is proportional to the fourth power of the high on-axis ray</li>
<li>In focusing heavily on the object side to move first, counting from one group behind, which varies significantly higher on-axis ray</li>
<li>Canon’s patents, and by fixing the first two groups, counting from the back of the eye movement to limit the amount counted from the first team back, suppressing the fluctuation of spherical aberration</li>
</ul>
<div><strong>via [<a href="http://egami.blog.so-net.ne.jp/2011-09-16">EG</a>]</strong></div>
 
Can we please just get a 200-400 f/4 zoom? Please? Before I go buy a Nikon? I'd really like to be able to take a decent photo at 400mm when skies are gray without being stuck with a prime. Thanks Canon.
 
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GMCPhotographics said:
Can someone knowledgable please explain the three examples? Surely these are three different lenses? A 70-300, a 100-400 and a 100-300. Is this correct?

Contrary to polular beleive, patents are not granted to specific lenes designs but to solutions of optical problems (see claims section of patents or patent applications). Examples that demonstrate said solutions are of course more interesting to general public as they demonstrate (more or less) practical lenses and some of them may even see production.
 
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J. McCabe said:
Why is the image height 21.64mm ?

Is it because those are APS-C lenses, or because that's half the radius required to cover an FF sensor ?

I'd assume it's the radius of the image circle (not half the radius, since the radius is already half the diameter). EF lenses have a 43.2 mm diameter image circle, and 2 x 21.64 mm = 43.3 mm.
 
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Mihast said:
Contrary to polular beleive, patents are not granted to specific lenes designs but to solutions of optical problems (see claims section of patents or patent applications). Examples that demonstrate said solutions are of course more interesting to general public as they demonstrate (more or less) practical lenses and some of them may even see production.

Exactly correct. In addition, it's not a given that Canon (or any other lens designer) would file patents for a new design only if it is an improvement. They might even file a patent they have no intention of ever using. Their designers are working all the time and let's say they come up with a new design that is almost as good as their current design. They might file the patent to prevent say Sigma from using it to market a lens that is seen as almost as good as the Canon but lower price.
 
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I have no idea how to read patents so ... can anyone tell if this would still be a push-pull design? rotating zoom would be much preferred ... although frankly, with the 2X on the 70-200 f/2.8, I'm not really in the market for a repeat lens in this range.
 
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smirkypants said:
Can we please just get a 200-400 f/4 zoom? Please?
They announced it a while ago... only a matter of time before it's in production. Someone more geeky than me might be able to say how long a typical delay is between announcement and production release.

kubelik said:
I have no idea how to read patents so ... can anyone tell if this would still be a push-pull design?
I think this is only for the optical formula, and nothing to do with the build.
 
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It doesn't matter if you have the best there is. Someone will still want "better".

Specifically on a hypothetical 100-400L II, I think the most significant changes will be in areas other than the basic optics. The push-pull vs. twist argument will probably go on forever but at the end of the day you get what you're given or look elsewhere. Updated IS would be a given, and I'd expect a weather sealing upgrade too. If the optics are improved on top of that, I don't think there's much to complain about other than the price tag.
 
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I agree with DAVE, there is nothing wrong with the current 100-400mm. I just bought one and the IQ/sharpness is quite amazing. I'd say it's on par with my 400mm f/5.6. The push/pull zoom does require some getting used to, but certainly not a deal breaker.

I've worked filing and defending patents. The big problem is defending patents. These patents were probably filed to protect the design and does not mean that a ver II will come out anytime soon.
 
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kubelik said:
I have no idea how to read patents so ... can anyone tell if this would still be a push-pull design? rotating zoom would be much preferred ... although frankly, with the 2X on the 70-200 f/2.8, I'm not really in the market for a repeat lens in this range.

After reading thru the entire patent, I would say that its probably a push-pull. 5 lens groups move foward while zooming while the 6th and rearmost group moves only with the focus ring to focus. Typically, rotating zoom rings only move some of the elements while others are fixed. You can, of course design it as a rotating zoom ring, bit it doesn't sound practical to move the first 5 lens groups a large distance.
 
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photophreek said:
I agree with DAVE, there is nothing wrong with the current 100-400mm. I just bought one and the IQ/sharpness is quite amazing. I'd say it's on par with my 400mm f/5.6. The push/pull zoom does require some getting used to, but certainly not a deal breaker.

I've worked filing and defending patents. The big problem is defending patents. These patents were probably filed to protect the design and does not mean that a ver II will come out anytime soon.
"won't come out soon" -- definitely agree . . .

But if you read through pretty much every one of "Roger's Take"s on LensRentals.com, you'll see that nothing wrong doesn't mean a better lens won't come out. (Depends on how much you're REALLY trying to avoid actual work). Canon has had some darned good lenses that it released a "II" version of and had marked improvement . . . so it's never say never.

Besides, releasing an even better version of an excellent lens means that the previous version is 'worth less' than it was before, used ;) *IF* Canon ever did release a MkII of the 100-400, I think it would be a home-run . . . it wouldn't be worth it otherwise, no?
 
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