# Patent: Canon Continues Stacked BSI Sensor Development



## Canon Rumors Guy (Apr 26, 2018)

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Stacked sensor related patents continue to roll out from Canon. <a href="https://www.canonnews.com/canon-continues-to-work-on-stacked-bsi-sensors">Canon News has uncovered</a> the latest in a long list of stacked sensor patents.</p>
<p><strong>Canon News breaks down the patent:</strong></p>
<blockquote><p>In another patent application describing stacked BSI sensors, canon looks to solve problems with high melting point metal is moved from being on the sensor substrate to only on the peripheral circuit substrate.  They are concerned that the high melting point metal will diffuse into the photo diodes collecting image data. <a href="https://www.canonnews.com/canon-continues-to-work-on-stacked-bsi-sensors">Read the full breakdown</a></p></blockquote>
<p>It’s worth noting that this sort of technology is especially important for mirrorless camera applications as it improves performance as well an improved ability to collect light at “high incident angles” says Canon News.</p>
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## Mt Spokane Photography (Apr 26, 2018)

A mirrorless camera does not have the issue by virtue of being mirrorless, the issue applies to cameras with a lens close to the sensor and the resulting high incidence angles. That's one of the reasons I do not want to see a new short flangeback lens for a mirrorless camera. The Image IQ's for such a setup suffers in more than one way.

A Mirrorless using native EF lenses would not have the issue.


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## hmatthes (Apr 26, 2018)

Mt Spokane Photography said:


> A mirrorless camera does not have the issue by virtue of being mirrorless, the issue applies to cameras with a lens close to the sensor and the resulting high incidence angles. That's one of the reasons I do not want to see a new short flangeback lens for a mirrorless camera. The Image IQ's for such a setup suffers in more than one way.
> 
> A Mirrorless using native EF lenses would not have the issue.



I am a bit confused since a "mirrored" camera has a longer flange distance = lower angle of incidence.
Short flange distances, such as mirrorless designs, have the higher angle of incidence. 

This is why Leica M & L mount cameras have sensors with microcells designed for such high angles of incidence. Their R lenses were designed for a higher angle of incidence (The Leicaflex had a mirror and film did not react as much to the angles of incidence).
The designer's dilemma is to design microcells to accept both high and low angle at the outer edges.

As always, lenses perform best on cameras designed by the same engineering teams. Canon "L" glass looks better at the edges on my old 6D than on a Sony E Mount or on a borrowed new Leica SL with mount adapter. Still look great though!


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## canonnews (Apr 26, 2018)

Mt Spokane Photography said:


> A mirrorless camera does not have the issue by virtue of being mirrorless, the issue applies to cameras with a lens close to the sensor and the resulting high incidence angles. That's one of the reasons I do not want to see a new short flangeback lens for a mirrorless camera. The Image IQ's for such a setup suffers in more than one way.
> 
> A Mirrorless using native EF lenses would not have the issue.



yes you are correct. i should have made that distinction. mirrorless in general will benefit from stacked sensors because it allows for faster framerates, electronic shutter with no rolling shutter effect,etc moreso than a single substrate version. these all benefit mirrorless more than DSLR's. BSI allows for short registration distance cameras to improve their response on high incidence angle light at the corners and general overall efficiency.

it's something that Canon needs to catch up with, and fairly quickly if they want some of the higher performance improvements that just about everyone else is coming out with these days.

it's encouraging to see so many patent applications in this area, it's probably one of the highest areas of investigation and application by Canon in the last 6 months or so that i've been looking at the applications.


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## sleepnever (Apr 26, 2018)

Isn't the stacked BSI sensor technology what Nikon is using in their awesome D850? I'm hoping that the reason we're not seeing a 5DSR II this year is that they're trying to get their sh*t together on a BSI sensor to compete in this market of which they're behind.


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## canonnews (Apr 26, 2018)

sleepnever said:


> Isn't the stacked BSI sensor technology what Nikon is using in their awesome D850? I'm hoping that the reason we're not seeing a 5DSR II this year is that they're trying to get their sh*t together on a BSI sensor to compete in this market of which they're behind.



The D850 doesn't use a stacked sensor but don't let that stop you venting


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## jolyonralph (Apr 26, 2018)

Mt Spokane Photography said:


> hat's one of the reasons I do not want to see a new short flangeback lens for a mirrorless camera. The Image IQ's for such a setup suffers in more than one way.



It's perfectly possible to make quality short flangeback lenses for a mirrorless camera. Look at the Sony/Zeiss offerings on FE mount for example.


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## 3kramd5 (Apr 26, 2018)

canonnews said:


> . mirrorless in general will benefit from stacked sensors because it allows for... no rolling shutter effect


Only if there is global readout.


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## maxfactor9933 (Apr 27, 2018)

canon should have done it 7 years ago.. when original 7d came out. from these rumor to actual productions unit takes years


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## Mt Spokane Photography (Apr 28, 2018)

jolyonralph said:


> Mt Spokane Photography said:
> 
> 
> > hat's one of the reasons I do not want to see a new short flangeback lens for a mirrorless camera. The Image IQ's for such a setup suffers in more than one way.
> ...



Its not about the lens, its the camera sensor configuration. The light rays strike the sensor at a sharper angle of incidence and more light is lost. This is a issue even with long flangeback lenses.

Canon also has a patent for dual pixel sensors that configures the outer rows of them to be ngled toward the lens to help overcome the effect. In the patent, they mention some of the drawbacks and issues caused to iq by short flange to sensor distances.


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## 3kramd5 (Apr 29, 2018)

maxfactor9933 said:


> canon should have done it 7 years ago.. when original 7d came out. from these rumor to actual productions unit takes years



This isn’t a rumor, it’s a patent. It could be in production for all anyone knows.


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## woodman411 (Apr 29, 2018)

sleepnever said:


> Isn't the stacked BSI sensor technology what Nikon is using in their awesome D850? I'm hoping that the reason we're not seeing a 5DSR II this year is that they're trying to get their sh*t together on a BSI sensor to compete in this market of which they're behind.



If you're impressed with the d850 sensor, you're impressed with Sony. Nikon has basically become the DSLR arm of Sony. When Nikon releases a FF-mirrorless, it will act as a "satellite team" for Sony, meaning they will not get the latest or best sensors to keep them in their place. So it's really a two-horse sensor race between Sony and Canon, and although I agree that Canon is behind, it is not that far back as DPR has one believe (in fact, Canon sensors have advantages over Sony, including dual-pixel and color science).


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## dak723 (Apr 29, 2018)

Mt Spokane Photography said:


> jolyonralph said:
> 
> 
> > Mt Spokane Photography said:
> ...



And, yes, it is possible to create lenses that do their best to overcome the problems inherent with the short flange distance. Perhaps that is why the Sony/Zeiss offerings mentioned are either or both longer/very expensive. For many of us, those two characteristics will deter us from choosing a short flange distance camera.


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## 3kramd5 (Apr 30, 2018)

woodman411 said:


> sleepnever said:
> 
> 
> > Isn't the stacked BSI sensor technology what Nikon is using in their awesome D850? I'm hoping that the reason we're not seeing a 5DSR II this year is that they're trying to get their sh*t together on a BSI sensor to compete in this market of which they're behind.
> ...



Nikon doesn’t use a Sony sensor in D850.


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## woodman411 (Apr 30, 2018)

3kramd5 said:


> woodman411 said:
> 
> 
> > sleepnever said:
> ...



Officially, they don't. Unofficially: https://www.sonyrumors.co/dpreview-nikon-d850-sensor-is-from-sony

Even if you don't believe that reference, for Nikon to pull out their first BSI FF sensor from scratch and then underprice the 5d4, just makes one wonder. The MP count is also close to the a7r's, another interesting coincidence. Oh, and it has the same green-cast issue as Sony sensors: https://www.dpreview.com/news/7999477966/nikon-d850-firmware-1-01-fixes-long-exposure-green-cast-and-other-minor-bugs


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## 3kramd5 (Apr 30, 2018)

woodman411 said:


> 3kramd5 said:
> 
> 
> > woodman411 said:
> ...



I don’t believe that reference, and I certainly don’t believe Nikon made them. I also don’t believe Sony has production lines for two full frame BSI. Option 3: there are plenty of CMOS fabs out there who are hungry for customers. It may as some rumors suggest be TPSCo.

Indeed it may be fabbed at the sony-owned Toshiba plant. As far as I know no one has torn one apart far enough to know definatively. 

Either way, it’s almost certainly not an off the shelf Sony design.


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