# Patent: Improved Flare Control For DO Elements



## Canon Rumors Guy (Feb 15, 2018)

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A <a href="http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20180045975">patent showing how to improved flare control with DO elements</a> has appeared. This goes along with some of the recent flare control patents we’ve seen for standard supertelephoto lenses.</p>
<p>This patent notes continued flare improvement for a 70-300 DO lens according to <a href="https://www.canonnews.com/canon-patent-application-for-improved-flare-control-for-do-elements">Canon News</a></p>
<p><strong><a href="http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20180045975">From US Patent 20180045975:</a></strong></p>
<blockquote><p>An image pickup apparatus for the long wavelength band of 8~14μm uses light (hereinafter, the far referred to as long wavelength infrared region). Therefore, if the diffraction efficiency of the diffractive optical element with respect to a specific diffraction order is low in a part of the far-infrared region, diffracted light having a diffraction order unnecessary for imaging can be generated. This is not preferable because it causes flare.</p></blockquote>
<p>While we don’t believe we’ll get an EF 60mm f/4 DO IS announcement in 2018, it’s always possible another DO lens could be on the way.</p>
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## tron (Feb 15, 2018)

Canon Rumors said:


> A <a href="http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20180045975">patent showing how to improved flare control with DO elements</a> has appeared. This goes along with some of the recent flare control patents we’ve seen for standard supertelephoto lenses.</p>
> <p>This patent notes continued flare improvement for a 70-300 DO lens according to <a href="https://www.canonnews.com/canon-patent-application-for-improved-flare-control-for-do-elements">Canon News</a></p>
> <p><strong><a href="http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20180045975">From US Patent 20180045975:</a></strong></p>
> <blockquote><p>An image pickup apparatus for the long wavelength band of 8~14μm uses light (hereinafter, the far referred to as long wavelength infrared region). Therefore, if the diffraction efficiency of the diffractive optical element with respect to a specific diffraction order is low in a part of the far-infrared region, diffracted light having a diffraction order unnecessary for imaging can be generated. This is not preferable because it causes flare.</p></blockquote>
> ...


You are right you don't believe you will get an EF 60mm f/4 DO IS announcement in 2018. I am certan that neither Canon does ;D ;D ;D

Now an EF600 f/4 DO IS is another matter ;D ;D ;D


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## Jack Douglas (Feb 16, 2018)

Well, no one else has a 60, do they.

Jack


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## Mt Spokane Photography (Feb 16, 2018)

I skimmed thru the patent, and saw that it covered the use of four different materials, but did not see any reference to a lens design or focal length, except that it applies to a DO lens.


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