# Patent: EF 400 f/4 DO IS II



## Canon Rumors Guy (Apr 15, 2013)

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<strong>Another DO patent</strong>

We haven’t seen a new DO lens in a long time, but the patents haven’t stopped. It looks like Canon is continuing the R&D, I’d love to see it go somewhere.</p>
<p><strong>Interpretation and self-description of the patent literature</strong></p>
<ul>
<li>Patent Publication No. 2013-64858</li>
<li>2013.4.11 Release Date</li>
<li>Filing date 2011.9.16</li>
</ul>
<p><strong>Example 1</strong></p>
<ul>
<li>Focal length f = 392.12mm</li>
<li>Fno. 4.12</li>
<li>Half angle of ω = 3.16 °</li>
<li>Image height Y = 21.64mm</li>
<li>262.14mm length lens</li>
<li>BF 69.97mm</li>
<li>Two fluorite</li>
<li>Materials and anomalous partial dispersion DOE to use, reduce the chromatic aberration</li>
<li>Refractive power of the diffractive surface</li>
<li>Strong, but can reduce the chromatic aberration of the element itself, flare increases</li>
<li>The weaker, other optical element DOE play a role</li>
<li>Refractive optical unit</li>
<li>DOE anomalous partial dispersion and bonding materials</li>
<li>DOE aspherical surface on the opposite side of the</li>
<li>Vibration control</li>
<li>Inner Focus</li>
</ul>
<p><strong>Source: [<a href="http://egami.blog.so-net.ne.jp/2013-04-14" target="_blank">EG</a>] | <a href="http://www.bhphotovideo.com/c/product/239654-USA/Canon_7034A002_Telephoto_EF_400mm_f_4_0.html/bi/2466/kbid/3296" target="_blank">Canon EF 400 f/4 DO IS</a></strong></p>
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## CrimsonBlue (Apr 15, 2013)

Price it at $2999 and you'll have quite a few takers who can't quite make the financial leap to the f/2.8 version


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## goulab (Apr 15, 2013)

CrimsonBlue said:


> Price it at $2999 and you'll have quite a few takers who can't quite make the financial leap to the f/2.8 version



and those who want to have a 400mm f4 while they do hiking or traveling


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## kubelik (Apr 15, 2013)

Realistically I think we're looking at $7500 to $9000 for this


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## eos650 (Apr 15, 2013)

I would be very interested if Canon made a regular 400mm f4. I would expect the price and size to be in the neighborhood of the 300mm f2.8, but probably a bit longer.

I have no interest in a a 400mm f4 DO lens. I'm not even sure that I would pay $2999 for the f4 DO, but I might be willing to pay $7000 for a regular 400mm f4.

I currently have a 200mm f2 and a 2x teleconverter, but the teleconverter degrades the image and slows focus too much for most applications (action, sports) that I would use it for. Another alternative would be the 300mm f2.8 with the 1.4x teleconverter. I expect that combination would work quite well, but I would love to have a native 400mm f4.


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## Stewbyyy (Apr 15, 2013)

I just want a sub $3000 400mm F/4. Non-IS, non-DO, I don't care.

A 400mm F/5.6 is just too slow, and a 300mm F/4 just doesn't get close enough. A 400mm F/2.8 is just too expensive.

Sigh.


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## dolina (Apr 15, 2013)

kubelik said:


> Realistically I think we're looking at $7500 to $9000 for this


+1,000

DO lenses are more expensive because of the compact and light weight design. I wonder how light this lens will be? I hope it will be at 1+kg. At that weight I would be inclined to take a long hard look at the lens.


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## ddashti (Apr 15, 2013)

How much improvement can Canon actually implement into the DO series?


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## Don Haines (Apr 15, 2013)

CrimsonBlue said:


> Price it at $2999 and you'll have quite a few takers who can't quite make the financial leap to the f/2.8 version


"new and improved" and "less than half the price of the old model" are probably not walking down the aisle hand in hand.....


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## Don Haines (Apr 15, 2013)

Stewbyyy said:


> I just want a sub $3000 400mm F/4. Non-IS, non-DO, I don't care.
> 
> A 400mm F/5.6 is just too slow, and a 300mm F/4 just doesn't get close enough. A 400mm F/2.8 is just too expensive.
> 
> Sigh.


sounds good to me....

I'd even like to see a sharper 400 F5.6 with IS...


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## Mt Spokane Photography (Apr 15, 2013)

This is yet another with their particle in resin technology "DOE anomalous partial dispersion and bonding materials".

They keep churning out patents for lenses using the technology, but have also noted that they can't control the particle dispersion closely enough to make the process practical. The spacing and distribution of the particles is critical to bend the desired wavelengths of light.

Obviously, they believe that they can bring the process to production. If they do, it can reduce the length of lenses by a substantial amount, and potentially improve the IQ of DO lenses.

DO lenses can bend light waves larger amounts than glass and still not be plagued with CA's. The payoff of a successful particle in resin radial dispersion lens elements will be high. And expect the price to be breath taking, at least initially. They might only be able to use one of one hundred or less lens elements produced.


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## CharlieB (Apr 15, 2013)

consider please, that sometimes patents are applied for, and granted, for designs that will never see the light of day, if only to thwart the competition rather than make actual products


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## goulab (Apr 15, 2013)

Just a question, is it the only DO tele patent ? You "heard" something for 300mm, 500, 600... ?


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## TrumpetPower! (Apr 15, 2013)

Canon is in a bit of an awkward position, it seems.

First, I'm sure that, eventually, DO will be everywhere. I can easily imagine even moderate focal length lenses getting the DO treatment to turn them into fast pancakes.

But it's obviously not easy doing it with today's technology.

What's worse...well, anybody willing to blow big bucks on a Great White isn't interested in compromising image quality. The IQ hit the 400 DO takes...well, why bother if the 400 f/5.6 at a stop higher ISO gives better IQ with the same shutter speed for a fraction of the price _and_ the weight?

So, until Canon can get the image quality of a DO lens not only on a par with their other Great Whites but even a step ahead, it's going to continue to be the redheaded stepchild of the imaging world.

But, in the mean time, they've still got to keep making the things and basically not selling them. Doesn't make for a very easy path from here to there.

Cheers,

b&


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## RGF (Apr 15, 2013)

Stewbyyy said:


> I just want a sub $3000 400mm F/4. Non-IS, non-DO, I don't care.
> 
> A 400mm F/5.6 is just too slow, and a 300mm F/4 just doesn't get close enough. A 400mm F/2.8 is just too expensive.
> 
> Sigh.



Well it would most certainly be IS. DO or non-DO?

400 F5.6 IS (new lens) would probably be ~$2000. Add a stop which doubles that amount of glass (gross approximation), the cost gets closer to $5000. Add DO technology to get the lens lighter, 50% premium - close to $8000.

I just don't see Canon coming out with this lens unless the IQ is on par with traditional design.


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## MSP (Apr 15, 2013)

Around $2k more than the current model sounds about right. I think there's a solid market for an updated version with the new 3 mode IS system IF they can improve the IQ, especially the bokeh. The images I've seen from the 400 DO are crisp where they're focused but have a strange, choppy bokeh, kind like the OOF areas when using a 2x extender. A 4lb, 400mm f4 with big white IQ and updated IS would be a sweet lens for a traveling sports/wildlife photographer.


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## Plainsman (Apr 15, 2013)

Why not a scaled down version of the superlative 300/2.8 II with a weight somewhat less due to 100mm aperture as against 107mm? 

The fact that this is another DO patent somehow confirms to me anyway that a new 400/4 is a long way off - maybe never.

Also of course it would impinge on sales of the 300/2.8 It's all to all to do with marketing - not what the lens punter actually desires!!


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## Q8-MC (Apr 15, 2013)

Sorry guys. what does mean DO? and what the difference between DO and IS?


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## BrandonKing96 (Apr 15, 2013)

Q8-MC said:


> Sorry guys. what does mean DO? and what the difference between DO and IS?


DO is Diffractive Optics, and does not replace IS  allows the use of extremely low dispersion glass, which also has a low refractive index. The low dispersion reduces color fringes.


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## ajf (Apr 15, 2013)

I have been unable to find "Patent Publication No. 2013-64858". It doesn't seem to be a US application - US2013064858 relates to a polysaccharide for modulating immune response. Can you tell me where it was published?


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## Q8-MC (Apr 15, 2013)

BrandonKing96 said:


> Q8-MC said:
> 
> 
> > Sorry guys. what does mean DO? and what the difference between DO and IS?
> ...




Big thaaanks bro


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## thebowtie (Apr 15, 2013)

ajf said:


> I have been unable to find "Patent Publication No. 2013-64858". It doesn't seem to be a US application - US2013064858 relates to a polysaccharide for modulating immune response. Can you tell me where it was published?


I would say Japan (considering Canon is a Japanese company - they would file all initial Patent applications in Japan, and use world-wide agreements on IP protection whilst they filed patents elsewhere)


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## ajf (Apr 15, 2013)

thebowtie said:


> ajf said:
> 
> 
> > I have been unable to find "Patent Publication No. 2013-64858". It doesn't seem to be a US application - US2013064858 relates to a polysaccharide for modulating immune response. Can you tell me where it was published?
> ...



Thanks. I have now found it on the Japanese IPO website.


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## jrista (Apr 15, 2013)

dolina said:


> kubelik said:
> 
> 
> > Realistically I think we're looking at $7500 to $9000 for this
> ...



With the fluorite elements added in, I would expect a 400/4 DO to be VERY light weight. Especially if it also uses the new barrel materials found on the 300/2.8 II and its friends.

A lot of the price of these things has to do with the materials costs. It is far from cheap to grow flawless fluorite crystals, or properly etch DO glass elements, or even produce high quality optical glass. The first generation DO lenses lacked IQ a bit as they used a diffraction grating approach. I think new designs have moved towards particle dispersion in optical glass, which should offer significantly superior IQ.

I think the DO game will really get interesting when Canon ANNOUNCES 500, 600, and 800mm DO lenses at half the weight and shorter physical lengths than the current designs. They will probably cost the same, will probably not be quite as good as the non-DO but slightly better than the old generation versions of those lenses. The last generation of Canon supertelephoto lenses offered some of the best IQ you could get your hands on. That kind of IQ in a smaller, lighter, more manageable package that could easily be hand-held for hours...now THAT would be something very interesting.


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## Mt Spokane Photography (Apr 15, 2013)

goulab said:


> Just a question, is it the only DO tele patent ? You "heard" something for 300mm, 500, 600... ?


About a year ago, same DO Material, just a different focal length. Canon is covering them all with patents.

Don't expect to see one soon though.

http://www.canonrumors.com/2012/04/patent-new-diffractive-optic-patents/


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## Mt Spokane Photography (Apr 15, 2013)

jrista said:


> dolina said:
> 
> 
> > kubelik said:
> ...


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## WPJ (Apr 15, 2013)

What about a 100-400do lens.....f2.8


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## jrista (Apr 15, 2013)

WPJ said:


> What about a 100-400do lens.....f2.8



$15,000, anyone? ;P


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## TrumpetPower! (Apr 15, 2013)

jrista said:


> WPJ said:
> 
> 
> > What about a 100-400do lens.....f2.8
> ...



I think you're missing a zero....

b&


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## jrista (Apr 15, 2013)

TrumpetPower! said:


> jrista said:
> 
> 
> > WPJ said:
> ...



$150,000? Nah, I can't imagine even an f/2.8 100-400 zoom costing that much. I do think such a lens would probably cost as much as one of the supertele primes, though.


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## TrumpetPower! (Apr 15, 2013)

jrista said:


> TrumpetPower! said:
> 
> 
> > jrista said:
> ...



Well, the 1200mm f/5.6 is $120,000. Considering that a super lightweight 100-400 f/2.8 with exotic technologies would be at least as much of an engineering feat as the 1200, I'd fully expect a six-figure price tag.

Come back in a decade or two and it might be a different story. But today?

b&


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## jrista (Apr 15, 2013)

TrumpetPower! said:


> jrista said:
> 
> 
> > TrumpetPower! said:
> ...



The cost of the 1200mm, like the cost of all the other supertele primes, is all about the amount of glass. The front element of the 1200mm has to be at least 215mm in diameter! That is 43% larger than the largest currently in Canon's lineup, the f/4 front element of the 600mm supertele. In contrast, a 100-400mm lens would need a front element SMALLER than the 600mm, by about 6%, for an f/2.8 aperture at 400mm. A 100-400mm lens, being a zoom lens, would probably need a little more glass than the 600mm lens, hence my price of $15,000 rather than $13,000. Given that it uses both DO and Fluorite elements, however, it shouldn't be quite the engineering feat the 1200mm lens was a couple of decades ago...it is BECAUSE of the advancements with diffractive optics and fluorite that Canon could make it cheaper to go along with being lighter. 

And note...speaking in an entirely hypothetical context. ;P I don't ever see Canon making such a lens anyway. But if they did.


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## TrumpetPower! (Apr 15, 2013)

jrista said:


> The cost of the 1200mm, like the cost of all the other supertele primes, is all about the amount of glass.



Glass is melted sand. Glass is cheap -- even cheaper than a silicon wafer. Even fluorite is cheap and abundant.

What costs money is first the R&D; even Canon's very intelligent and skilled and very well paid engineers with all the equipment they might want at their disposal haven't yet truly figured out DO in the first place.

And what next costs money is the tooling. So you've got a bag of sand. How are you going to sinter it with the right trace elements into a bubble-free block the size you need? How're you going to grind that into the shape you need to the tolerances you need? How're you going to make however many thousands of these elements you need for the lenses you're going to sell, and where're you going to keep the individual machinery you're going to need for each different element? Or, how're you going to make a general-purpose lens manufacturing machine that can handle a broad range of the very different elements you need?

And let's not forget the housing, autofocus motors, IS gyros, and circuitry / firmware -- very little of which can be reused from lens to lens, especially with the big exotics.

Now, take the cost to make all the machinery -- again, the materials are a rounding error -- and divide by the number of lenses you expect to sell. Add in all the salaries you have to pay, all the taxes, all the shipping, all the environmental cleanup fees, all the rent, and a few pennies for the shareholders.

If you're going to sell lots of these lenses, you can spread that huge cost over all of them and wind up with a rather modest sale price.

But if you're only going to sell a few thousand, as I expect is the case with the Great Whites, then you have to make each buyer pay through the nose to offset all of that.

Think about it for a moment.

Do you _really_ think that a 1200 is as expensive to make on a per-lens basis as an exotic luxury sports sedan? Or that a 400 f/2.8 costs more to make than an econobox?

No -- of course not!

But the sales volume is so low for the lenses....

Cheers,

b&


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## RGF (Apr 16, 2013)

Mt Spokane Photography said:


> goulab said:
> 
> 
> > Just a question, is it the only DO tele patent ? You "heard" something for 300mm, 500, 600... ?
> ...



agree. Protect themselves just in case someone really cracks the code on how to make a DO really sharp.

Defensive patents, hold IP space.


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## GMCPhotographics (Apr 16, 2013)

TrumpetPower! said:


> jrista said:
> 
> 
> > The cost of the 1200mm, like the cost of all the other supertele primes, is all about the amount of glass.
> ...



I love the way so many "lens experts" come out of the woodwork on camera forums...have you hand grinded any of your own optics??? Have you designed your own lenses and popped them on a camera? No...I haven't either. 
According to various websites, the optics for the legendary ef 1200mm f5.6 were taken from the stock of FD 1200mm f5.6 lenses that Canon had. They made a new set of EF lenses, bu the optics were taken out of existing lenses. Canon haven't ground any EF front optics which is bigger than the current range of big whites (400/2.8, 600/f4, 800/5.6). Which leaves one to wonder if they no longer have that capability or they outsourced the original FD lens optics, which would explain why it's so darn expensive! It would also explain why Canon raided their old FD lenses to make only a handfull of the EF variants.


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## Leejo (Apr 16, 2013)

>> I love the way so many "lens experts" come out of the woodwork on camera forums...have you hand 
>> grinded any of your own optics??? Have you designed your own lenses and popped them on a camera? 
>> No...I haven't either. 
But my grandfather did most of his professional life - to military specs...

>> According to various websites, the optics for the legendary ef 1200mm f5.6 were taken from the stock of FD >> 1200mm f5.6 lenses that Canon had. They made a new set of EF lenses, bu the optics were taken out of 
>> existing lenses. Canon haven't ground any EF front optics which is bigger than the current range of big 
>> whites (400/2.8, 600/f4, 800/5.6). Which leaves one to wonder if they no longer have that capability or they
>> outsourced the original FD lens optics, which would explain why it's so darn expensive! 
>> It would also explain why Canon raided their old FD lenses to make only a handfull of the EF variants.
Having created them they are hardly going to throw them away - converting to EF was a good way to push those professionals who used such a lens to digital.
Plus if they had the machine they would have hardly have it sitting around for years totally unused.
On the other hand, what worked then is hardly going to work as well now.
Back then it was hardly likely to be digitally controlled measurement and stepping motors, that they would want to employ now.


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## TrumpetPower! (Apr 16, 2013)

GMCPhotographics said:


> Which leaves one to wonder if they no longer have that capability or they outsourced the original FD lens optics, which would explain why it's so darn expensive!



Had Canon outsourced production of the lens elements, they would have been cheaper, not more expensive. And they'd very likely still be available today, even if not packaged and sold by Canon.

That's because Canon wouldn't have outsourced to somebody smaller or less capable than themselves; they'd have outsourced to somebody who was already making such lenses, somebody who had already sunk the cost in R&D and tooling and what-not. Somebody whose own operation was so big that they had manufacturing capacity to spare for others, enough that they could sell to others for less than what it would cost to start from scratch -- else why buy from them in the first place?

That nobody else is selling camera lenses with >200mm front objectives should also be a pretty big clue that there isn't some secret mystical source of such beasts that Canon went to. By way of comparison, Meade's biggest refractor is comparable to Canon's current Great Whites, and other manufacturers of consumer refractors have similar specs at the top end of their lineups. It's only when you get out of the consumer realm into scientific instruments that you find anything in the range of the Canon 1200...and those, by definition, aren't mass-produced. Indeed, they're made in similar quantities to the Canon 1200, and cost as much...hmmm....

Cheers,

b&


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