# Patent: Dual Pixel Phase Detect AF While in AI Servo



## Canon Rumors Guy (Aug 12, 2014)

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<div style="float: right; margin:0 0 76px 0px;"><a href="https://twitter.com/share" class="twitter-share-button" data-count="vertical" data-url="http://www.canonrumors.com/2014/08/patent-dual-pixel-phase-detect-af-while-in-ai-servo/">Tweet</a></div>
<p>A new patent that integrates normal AF with phase detect AF has become public. This sort of technology could very much improve AF tracking in burst mode. Perhaps we’ll see this technology on the upcoming EOS 7D replacement?</p>
<p>If anyone can further clarify this patent, please do.</p>
<div id="attachment_17016" style="width: 411px" class="wp-caption alignnone"><a href="http://www.canonrumors.com/wp-content/uploads/2014/08/2014_142372_fig07.png"><img class="size-full wp-image-17016" src="http://www.canonrumors.com/wp-content/uploads/2014/08/2014_142372_fig07.png" alt="Phase Detect AF w/Normal AF" width="401" height="219" /></a><p class="wp-caption-text">Phase Detect AF w/Normal AF</p></div>
<p>Patent Publication No. 2014-142372</p>
<ul>
<li>Published Date 2014.8.7</li>
<li>Filing date 2012.1.22</li>
</ul>
<p><strong>Source: [<a href="http://egami.blog.so-net.ne.jp/2014-08-12" target="_blank">EG</a>]</strong></p>
<p><strong><span style="color: #ff0000;">c</span>r</strong></p>
```


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## Dylan777 (Aug 12, 2014)

Never enough for af accuracy. 1dx ii perhaps?


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## Mt Spokane Photography (Aug 12, 2014)

I'm expecting something like this. Canon wants to improve the tracking ability of the dual pixel technology to make it suitable for professional level autofocus. I expect some solution to be in all future CanonDSLR's.


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## Orangutan (Aug 12, 2014)

Mt Spokane Photography said:


> I'm expecting something like this. Canon wants to improve the tracking ability of the dual pixel technology to make it suitable for professional level autofocus. I expect some solution to be in all future CanonDSLR's.



And maybe take one more step toward pro-level mirrorless.


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## Mt Spokane Photography (Aug 12, 2014)

Orangutan said:


> Mt Spokane Photography said:
> 
> 
> > I'm expecting something like this. Canon wants to improve the tracking ability of the dual pixel technology to make it suitable for professional level autofocus. I expect some solution to be in all future CanonDSLR's.
> ...



That would be nice, but after getting bit with mirrorless technology 3 times, Canon is pretty shy. The Fiasco with the "M" cost them a bundle. Its nothing to do with the camera, just that the buyers that it targeted wanted nothing to do with it. They dumped them for a big loss.


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## Dylan777 (Aug 12, 2014)

Orangutan said:


> Mt Spokane Photography said:
> 
> 
> > I'm expecting something like this. Canon wants to improve the tracking ability of the dual pixel technology to make it suitable for professional level autofocus. I expect some solution to be in all future CanonDSLR's.
> ...



Makes that FF mirrorless with native pancake prime lenses, I can smell the trouble


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## Dylan777 (Aug 12, 2014)

Mt Spokane Photography said:


> Orangutan said:
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> 
> > Mt Spokane Photography said:
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I got smarter through my own mistakes.


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## Mt Spokane Photography (Aug 12, 2014)

Dylan777 said:


> Orangutan said:
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> > Mt Spokane Photography said:
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Perhaps if they targeted a mirrorless toward enthusiast buyers with a full sized body, it would sell. In a early interview, Canon stated or hinted that the M was targeted at women buyers in Japan. That demographic is apparently a big miss in USA and Europe. It sells in Asia.

I'd certainly welcome the demise of that flapping mirror.


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## Etienne (Aug 12, 2014)

Mt Spokane Photography said:


> Orangutan said:
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> 
> > Mt Spokane Photography said:
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It had everything to do with the camera. The EOS-M was woefully far behind the competition. The EOS-M is a good value at $300, but Canon has to do a lot better to compete with Sony, Fujifilm, Panasonic GH4 etc.

Canon can do it, and I think they will. The next EOS-M will be a killer because it has to be in order to compete. They have dual pixel AF, which is revolutionary and incredibly beneficial to a mirrorless cam. It's only a matter of time before Canon takes the lead on mirrorless I think.


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## RGF (Aug 12, 2014)

will dual pixel improve DR? or only AF? It would be nice if it would


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## Etienne (Aug 12, 2014)

RGF said:


> will dual pixel improve DR? or only AF? It would be nice if it would



I have no idea, but you can bet Canon is not sitting on their asses. They can see the danger of Sony, Panasonic, Fujifilm. It's been a game of leapfrog for a long time, and Canon will leap ahead soon. That's just my guess.


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## Lee Jay (Aug 12, 2014)

Mt Spokane Photography said:


> I'd certainly welcome the demise of that flapping mirror.



So would I, except for the fact that all the alternatives are dramatically worse.


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## weixing (Aug 12, 2014)

Hi,
I personally won't get a DSLR with EVF for birding/wildlife... it'll "eat" the battery very fast. If it's a hybrid (with option of using either optical or EVF), then I don't mind.

Anyway, may be the Dual Pixel Phase Detect AF is use to do fine adjustment to the AF when the mirror is up during the image capture phase... 

Have a nice day.


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## Dylan777 (Aug 12, 2014)

Mt Spokane Photography said:


> Dylan777 said:
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> 
> > Orangutan said:
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Sounds like they need to run new mirrorless campaign. This might help reversing that philosophy. And I *HOPE&WISH* for same type camera body that he's holding


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## PhotoCat (Aug 12, 2014)

Wow, this is really happening! 
AFMA hopefully will be eliminated altogether, now Canon can compare the results between
dual pixel sensor and normal phase-det sensor!!


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## mackguyver (Aug 12, 2014)

Soon we'll be able to shoot sports with our phones! If Canon licenses this to them, they can do Ai Servo and maybe we'll see the momtogs ditch their Rebels for their phone!

Okay, just being silly, but this makes sense as the "big" thing for the 7DII announcement.

P.S. Dylan, nice Arnold photo!


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## dgatwood (Aug 12, 2014)

The problem with mirrorless is that it has few real advantages and lots of disadvantages.

Its main advantage is the ability to make non-retrofocal wide angle lenses in the range from 22mm to about 40mm. So lenses within that tiny, narrow range get smaller. Your smallest lenses (the ones that were already light enough to not be a big deal) get smaller and lighter.

Unfortunately, because lenses longer than 40mm are already non-retrofocal, they don't benefit. Thus, most of your lenses stay the same size, but now require an adapter that reduces IQ subtly by adding another flex point, and adds another piece of hardware that you have to manage when out in the field. That's barely even an advantage, and for many people, is a disadvantage.

And the body gets thinner. Whee. That's such an advantage that I can hardly contain my giddiness. No, wait. The other thing. Boredom. If you use this to make the camera lighter, it becomes unwieldy because of the weight imbalance between the camera and the lens. And if you don't, then what's the point?

I suppose you can also do things like focus peaking through the viewfinder instead of having to do them on the live view display, though that's a pretty small benefit, IMO.

On the disadvantage side, you have much shorter battery life (no OVF), mandatory adapters on many lenses, and loss of night accommodation when shooting at night.

When you add all those things together, IMO most folks would be better off with a DSLR, using live view for those rare occasions when an EVF provides an advantage. And IMO most of the folks who are really better off with mirrorless (the folks who only use short lenses) would do just as well with a fixed-lens point-and-shoot.


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## Marauder (Aug 12, 2014)

weixing said:


> Hi,
> I personally won't get a DSLR with EVF for birding/wildlife... it'll "eat" the battery very fast. If it's a hybrid (with option of using either optical or EVF), then I don't mind.
> 
> Anyway, may be the Dual Pixel Phase Detect AF is use to do fine adjustment to the AF when the mirror is up during the image capture phase...
> ...



I concur. I want/need an OVF. Don't mind a hybrid that I can use or turn off as needed. I also agree that the DPAF may allow continual AF with the mirror down, handing off the AF information between the two systems, depending on which one has a view at a given instant. It may even be able to AF based on shape and colour of object, which would be very cool if it can be made to work reliably! I also think the idea that it may eliminate the need to calibrate lenses, which would be a HUGE benefit!

As to the mirrorless, I'm not particularly interested, but I agree that DPAF could be the way forward for Canon to compete in that marketplace. Still, I see mirrorless as an alternative to an SLR, rather than a replacement for it. 

My two cents worth...but pennies have been taken out of circulation here in Canada!


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## AvTvM (Aug 12, 2014)

1. I see a mirror flapping in that patent. 
2. To me it looks like a feedback loop for automatic, in-camera "AF-Micro-Adjustment". 

I do not se anything directly linked to dual-pixel AF [automatic AFMA for DSLR-phase-detect AF-unit could be achieved with any sort of additional in-sensor plane AF ... CD-AF and/or PD-AF] nor to improved Servo-Tracking performance. And I also fail to see how this patent might improve AF-capabilities of *mirrorless* cameras. 

As much as I am looking forward to the demise of the flapping mirror, too. ;D


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## RGomezPhotos (Aug 12, 2014)

It will be in the 1DX MKII and 5D MKIV. It might be a dumbed-down version in the 7D replacement. With tracking like that in the 7D replacement, it could eat sales of the 1DX.


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## LetTheRightLensIn (Aug 12, 2014)

Etienne said:


> RGF said:
> 
> 
> > will dual pixel improve DR? or only AF? It would be nice if it would
> ...



Perhaps, but it almost seem like they put their money on all sorts of dual pixel AF type stuff instead of improving low ISO image quality. It also probably costs less money to do with stuff than make the fancy new assemblies required to improve image quality.


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## 3kramd5 (Aug 12, 2014)

Lee Jay said:


> Mt Spokane Photography said:
> 
> 
> > I'd certainly welcome the demise of that flapping mirror.
> ...



For the time being, yes. But display and battery technologies march forward. Eventually, EVF may come without a significant penalty, and when that happens, I'll sign up for sure.


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## Mt Spokane Photography (Aug 12, 2014)

After reading thru the patent, which is one of those that tries to explain the operation of the camera starting with the creation of the galaxy and each step after that, here is my understanding. I can be wrong.

Simply put, when taking a photo using this invention:

1. the camera does a conventional phase detect and the lens focuses as directed

2. The mirror raises and the camera does a fast comparison of the live autofocus and the phase detect AF

3. The accuracy of the first measurement is compared and the focus may be slightly adjusted if necessary.


Then, there is the part explaining how phase detect accuracy can be affected by mirror bounce, sub mirror bending, humidity, and temperature. Apparently, a temperature / humidity detector is used to provide correction to the phase detect AF but not the live AF. That's something I did not know.


From this, I gather that the live AF can operate very quickly if its only looking for tiny corrections in the focus, and since focus has been carried out first by the conventional phase detect system, the invention will further tweak focus accuracy.

The outcome is that focus errors caused by the high speed of the flapping mirror, and submirror while trying to capture images with a high FPS will be corrected. There is not time enough to allow those moving parts to stabilize when shooting at 12 fps, and AF accuracy suffers. 

Will it happen in a 7D MK II? My opinion is that we will see it because its consistent with earlier rumors.


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## Steve (Aug 12, 2014)

dgatwood said:


> Unfortunately, because lenses longer than 40mm are already non-retrofocal, they don't benefit. Thus, most of your lenses stay the same size, but now require an adapter that reduces IQ subtly by adding another flex point, and adds another piece of hardware that you have to manage when out in the field. That's barely even an advantage, and for many people, is a disadvantage.



Where exactly are you getting the idea that lenses longer than 40mm for mirrorless cameras require mandatory adapters?


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## lol (Aug 12, 2014)

Marauder said:


> It may even be able to AF based on shape and colour of object, which would be very cool if it can be made to work reliably!


I believe such a thing already exists in the 1D X as well as many higher end Nikon bodies. They use the metering sensor to provide that info. Bit disappointed to see this got cut out when they made the 5D3. Really hope it makes the 7D2.


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## Marauder (Aug 12, 2014)

lol said:


> Marauder said:
> 
> 
> > It may even be able to AF based on shape and colour of object, which would be very cool if it can be made to work reliably!
> ...



Yes, something like this does exist for the 1DX. I'm just wondering if this patent possibly represents a new way of implementing this by using the image sensor. The 7D II, being designed as a wildlife/action camera would be a very logical product for such a technological innovation.


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## LetTheRightLensIn (Aug 12, 2014)

Mt Spokane Photography said:


> After reading thru the patent, which is one of those that tries to explain the operation of the camera starting with the creation of the galaxy and each step after that, here is my understanding. I can be wrong.
> 
> Simply put, when taking a photo using this invention:
> 
> ...



Could be super awesome for the action shooters.   (maybe for video too )

I just hope they manage to be able to catch up for landscape stuff. :-\

I just hope they manage to be able to catch up for landscape stuff. :-\ I guess, if they don't mess up the video, one could sell off all Canon FF bodies, buy 7D2 for action and Sony A7R for landscapes??


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## LetTheRightLensIn (Aug 12, 2014)

lol said:


> Marauder said:
> 
> 
> > It may even be able to AF based on shape and colour of object, which would be very cool if it can be made to work reliably!
> ...



I wonder how well the Canon implementation of color tracking works though. When was the last time you heard someone with a 1DX even bother to mention it? It also requires that all AF points be used for tracking at once with the Canon at least.


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## Dylan777 (Aug 12, 2014)

Marauder said:


> lol said:
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> > Marauder said:
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It calls EOS iTR AF. I have this feature turned off when shooting bird in flight. It works well on kids with colorful clothes.


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## scottkinfw (Aug 13, 2014)

The prospect of improved AF is exciting no matter what the technology. I can't wait to see what comes and how it actually performs in the field. I also can't wait to see what bodies it comes it. Hopefully the new sensors won't be hampered by the new technology.

sek


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## dgatwood (Aug 13, 2014)

Steve said:


> dgatwood said:
> 
> 
> > Unfortunately, because lenses longer than 40mm are already non-retrofocal, they don't benefit. Thus, most of your lenses stay the same size, but now require an adapter that reduces IQ subtly by adding another flex point, and adds another piece of hardware that you have to manage when out in the field. That's barely even an advantage, and for many people, is a disadvantage.
> ...



You're subtly misinterpreting what I said. What I said was that there's no benefit to the shorter flange distance for lenses longer than 40mm, and as a result, most Canon lenses (particularly longer lenses) are built exclusively in EF or EF-S format, and require an adapter to use them on an EF-M camera.

I would note, however, that Canon just released a 55–200 in EF-M format. That at least makes EF-M a little bit less absurdly broken as a platform. Up until last month, EF-M was pretty much a sad joke....


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## jrista (Aug 13, 2014)

Lee Jay said:


> Mt Spokane Photography said:
> 
> 
> > I'd certainly welcome the demise of that flapping mirror.
> ...



Agreed. A viable alternative hasn't presented itself yet.


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## wickidwombat (Aug 13, 2014)

dgatwood said:


> I would note, however, that Canon just released a 55–200 in EF-M format. That at least makes EF-M a little bit less absurdly broken as a platform. Up until last month, EF-M was pretty much a sad joke....



damn mine must not have got the memo that it was a sad joke as it still takes great photos...
so does my IR converted one 

but then i use the 11-22 90% of the time and occassionally my rokinon 8mm on it


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## vscd (Aug 13, 2014)

> When you add all those things together, IMO most folks would be better off with a DSLR, using live view for those rare occasions when an EVF provides an advantage. And IMO most of the folks who are really better off with mirrorless (the folks who only use short lenses) would do just as well with a fixed-lens point-and-shoot.



Wise words, spoken calmly. That's exactly my point of view, but try to have a chit chat with a recent fuji-fanboy. Useless... ;D


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## Sabaki (Aug 13, 2014)

Marauder said:


> lol said:
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> > Marauder said:
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Certainly seems like something Canon should put into the 7Dii. It's in the D810 for crying out loud and that's not an action type body.


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## lw (Aug 13, 2014)

Would be nice if this could be applied via a firmware update to the 70D.

If it is all in the algorithms, and not new hardware components, perhaps that is possible.


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## 2n10 (Aug 13, 2014)

lw said:


> Would be nice if this could be applied via a firmware update to the 70D.
> 
> If it is all in the algorithms, and not new hardware components, perhaps that is possible.



If it is algorithms then yes a firmware update would work. If there are hardware differences it may take a little time to get it right.


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## Steve (Aug 13, 2014)

dgatwood said:


> You're subtly misinterpreting what I said. What I said was that there's no benefit to the shorter flange distance for lenses longer than 40mm, and as a result, most Canon lenses (particularly longer lenses) are built exclusively in EF or EF-S format, and require an adapter to use them on an EF-M camera.



So your post was only outlining the problems of the EOS M system and not mirrorless technology in general?


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## Marauder (Aug 13, 2014)

Sabaki said:


> Marauder said:
> 
> 
> > lol said:
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Yeah, if they can get it to work well with fast moving subjects, especially birds, it would be a big benefit! If!!


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## dgatwood (Aug 13, 2014)

Steve said:


> dgatwood said:
> 
> 
> > You're subtly misinterpreting what I said. What I said was that there's no benefit to the shorter flange distance for lenses longer than 40mm, and as a result, most Canon lenses (particularly longer lenses) are built exclusively in EF or EF-S format, and require an adapter to use them on an EF-M camera.
> ...



That part was, anyway.


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