Patent: EF 400 f/4 DO IS II

[Canon Rumors]

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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>

 

[CrimsonBlue]

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

 

[goulab]

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

 

[kubelik]

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

 

[eos650]

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.

 

[Stewbyyy]

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.

 

[dolina]

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.

 

[ddashti]

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

 

[Don Haines]

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.....

 

[Don Haines]

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...

 

[Mt Spokane Photography]

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.

 

[CharlieB]

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

 

[goulab]

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

 

[TrumpetPower!]

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&

 

[RGF]

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.

 

[MSP]

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.

 

[Plainsman]

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!!

 

[Q8-MC]

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

 

[BrandonKing96]

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.

 

[ajf]

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?