# Patent: Variable Diffusion Focusing Screen



## Canon Rumors Guy (Oct 15, 2014)

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<p>A patent for a variable diffusion focusing screen from Canon is out there. The patent shows a focusing screen capable of showing sharp areas as well as giving the shooter a better idea of depth of field. Current DSLRs are quite difficult to manually focus accurately using fast primes with the default focusing screens. There are focusing screens out there you can swap out, but having it all in one screen would be ideal.</p>
<p><a href="http://www.canonrumors.com/wp-content/uploads/2014/10/patentfocusingscreen.jpg"><img class="alignnone size-full wp-image-17597" src="http://www.canonrumors.com/wp-content/uploads/2014/10/patentfocusingscreen.jpg" alt="patentfocusingscreen" width="398" height="140" /></a></p>
<p><strong>Patent Publication No. 2014-191184</strong></p>
<ul>
<li>Published Date 2014.10.6</li>
<li>Filing date 2013.3.27</li>
</ul>
<p><strong>Canon patents</strong></p>
<ul>
<li>Spreading factor variable finder screen</li>
<li>First diffusion rate</li>
<li>Brightness priority</li>
<li>Setting of low diffusivity and high transmittance</li>
<li>Second diffusion rate</li>
<li>Blur priority</li>
<li>Setting of high diffusivity and low transmittance</li>
<li>The partially changed spreading factor according to the focusing range</li>
</ul>
<p>Source: [<a href="http://translate.google.com/translate?sl=auto&tl=en&u=http://egami.blog.so-net.ne.jp/2014-10-15" target="_blank">EG</a>] via [<a href="http://www.northlight-images.co.uk/cameras/Canon_rumours.html" target="_blank">NL</a>]</p>
<p><strong><span style="color: #ff0000;">c</span>r</strong></p>
```


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## neuroanatomist (Oct 15, 2014)

Sweet!


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## Eldar (Oct 15, 2014)

Please make this happen!!!


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## AcutancePhotography (Oct 15, 2014)

Lets just hope this not just a patent that will be buried. 

This is something I think a lot of photographers would like.


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## 2n10 (Oct 15, 2014)

Very cool.


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## Click (Oct 15, 2014)

Very nice.




AcutancePhotography said:


> Lets just hope this not just a patent that will be buried.
> 
> This is something I think a lot of photographers would like.



+1


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## IsaacImage (Oct 15, 2014)

Great idea !
Would love to see it in real life !


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## Maximilian (Oct 15, 2014)

WOW!

I wouldn't have even thought about this beeing possible. 
So if this comes true, then nobody should call Canon "not innovative" again.

Let's hope it will find its way into cameras.


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## Orangutan (Oct 15, 2014)

That kind of detailed focus info would require a lot of data -- wouldn't this make sense only if there are a very large number of focus detection points?


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## Lee Jay (Oct 15, 2014)

I don't care how much diffusion the focusing screen provides, I don't think manual focus is reliable without a split prism.


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## zim (Oct 15, 2014)

Lee Jay said:


> I don't care how much diffusion the focusing screen provides, I don't think manual focus is reliable without a split prism.



+1 split prism option from canon, without it costing the earth please, sorted!


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## Joe M (Oct 15, 2014)

I would pre-order this without hesitation. 

I had to come back and add this....
So often over the years, I've heard Canon say they've added such and such feature to whichever camera because they've spoken with photographers and that's what those photographers wanted. Well, finally, here is something I really want (likely years away if ever) and I'd expect many others want too. Sort it out and hand it over Canon.


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## NancyP (Oct 15, 2014)

If this truly worked as well as a standard screen alternating with a super-fine screen, I would be all over it in a New York minute.


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## Coldhands (Oct 15, 2014)

Orangutan said:


> That kind of detailed focus info would require a lot of data -- wouldn't this make sense only if there are a very large number of focus detection points?



It's not related to the autofocus system - it's just a transparent material whose diffusion can be changed. More diffusion=easier to judge focus, but less bright (and vice-versa). Its technology is probably similar to this: http://www.google.com/patents/WO2013098522A1?cl=en


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## caruser (Oct 15, 2014)

So where when can I buy one?


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## iron-t (Oct 15, 2014)

This is cool, but will it allow accurate enough MF for very thin DOF in critical applications? Not sure.

Wonder if the business people at Canon will put the kibosh on this tech given the very high quality MF-only lenses from Zeiss and the very affordable MF-only lenses from Samyang.


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## Besisika (Oct 15, 2014)

Eldar said:


> Please make this happen!!!


+1 
"Please make this happen!!!" and QUICK. Need it now.


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## 9VIII (Oct 15, 2014)

iron-t said:


> This is cool, but will it allow accurate enough MF for very thin DOF in critical applications? Not sure.
> 
> Wonder if the business people at Canon will put the kibosh on this tech given the very high quality MF-only lenses from Zeiss and the very affordable MF-only lenses from Samyang.



I can barely take a picture of a cat with my 85f1.4 right now, I don't care if isn't good enough for the most critical uses, it'll be a huge improvement.


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## ScottyP (Oct 15, 2014)

Ha. Zeiss should have invented this for Canon years ago so they can sell these to people to whom they sell their Rolls Royce manual fast primes.


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## drmikeinpdx (Oct 15, 2014)

That would be a very nice feature if it worked. I'd have to see some positive reviews before I was convinced.


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## The Bad Duck (Oct 15, 2014)

I like it!


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## Mitch.Conner (Oct 15, 2014)

I was just looking at focusing screens at focusingscreens.com but this is even better.


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## AcutancePhotography (Oct 15, 2014)

Mitch.Conner said:


> I was just looking at focusing screens at focusingscreens.com but this is even better.



The difference is that at FS.com you can buy something today, this variable FS is just a patent. Who knows when or if it will ever be produced.


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## mrsfotografie (Oct 15, 2014)

Totally cool!


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## gbchriste (Oct 15, 2014)

And forgive my ignorance but why aren't modern DSLRs fitted with split prism focusing screens. I shot with a Canon AE-1 and/or A-1 for 20 years and never, ever missed focus on anything. I was 50/50 in focus with the 5DII and 70-200 2.8 Mk I. Now with the 5DIII and 70-200 MkII I'm about 90% in focus but still...


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## jrista (Oct 15, 2014)

Cool stuff! I wonder if this would work in conjunction with Canon's existing transmissive LCD and all the visual cues and feedback available in their current OVFs.


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## Lee Jay (Oct 15, 2014)

gbchriste said:


> And forgive my ignorance but why aren't modern DSLRs fitted with split prism focusing screens. I shot with a Canon AE-1 and/or A-1 for 20 years and never, ever missed focus on anything. I was 50/50 in focus with the 5DII and 70-200 2.8 Mk I. Now with the 5DIII and 70-200 MkII I'm about 90% in focus but still...



As I understand it, there are two reasons - most people use AF and so it's not really needed, and second because the split prism can affect the exposure sensor's reliability in getting the exposure correct.


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## DominoDude (Oct 15, 2014)

This can't be a reality too soon!
I would love for it to come in combination with a split prism moved closer to the dioptre in the viewfinder - well out of the way from any sensors in the path.


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## andrewflo (Oct 15, 2014)

This is absolutely an exciting concept. But to be honest, I feel like the reality is nothing can be assumed from just a patent.

Canon has patents for all kinds of crazy cameras and lenses. They have a patent for a 24-70mm f/2.8 IS but have yet to produce a consumer-ready product following this patent.

Not to say they are 100% not innovative, but I don't think this patent relinquishes them from their recent downfalls until the technology actually comes to fruition.


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## LetTheRightLensIn (Oct 15, 2014)

very cool, assuming it is precise and quick enough to really work well which it might not be, but if it actually somehow is....


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## Good24 (Oct 16, 2014)

This would be great. I assume future cameras would come with it (and/or with more easily swappable screens). It's probably too much to ask that you could send in your 5D or 7D to have it professionally retrofitted with one of these when the day is realized. I've read that replacing the focus screen yourself if you don't know what you're doing can be a dangerous proposition (and I don't know what I'm doing).

I often manual focus with live view. It's good, it works. But I would prefer a better screen, or at least the option.


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## ejenner (Oct 16, 2014)

It would be very cool.

So considering it's Canon, I doubt it will happen until 5 years after Sony has one and 2 years after Nikon has one.


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## Bennymiata (Oct 16, 2014)

A great company is not made from their patents, but from their products.
Come on Canon, get this to market -- ASAP!


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## justaCanonuser (Oct 16, 2014)

This could save DSLRs a bit of a longterm future market... I'd love having this already in my 5D3 and 7D. For my old 7D I am seriously considering to get a split microprism screen but this would be on the cost side of losing LCD enhancement. Could also be sometimes helpful if you want to MA fast Canon primes.


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## Lawliet (Oct 16, 2014)

Maximilian said:


> I wouldn't have even thought about this beeing possible.
> So if this comes true, then nobody should call Canon "not innovative" again.



Its quite common in interior design, make a door or seperation wall transparent/frosted/darkened on the press of a button, or by a slider on your cell phone.
The most public use I can think of would be in the ICE high speed trains - sudden whiteout? Likley a sheep that didn't make it off the track in time? Or something akin.


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## rfdesigner (Oct 16, 2014)

Love the patent idea.. would give precision manual focussing at any point across the screen, unlike a split prism...


Dumb question / suggestion.

Zeiss/anyone else making MF lenses should offer a free/cost-price split prism focusing screen for a DSLR of the purchasers choice when buying a lens.

Given the cost of a Zeiss lens there's got to be financial room in there to do this... they could include a fitting service too.

That would have to increase sales!


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## that1guyy (Oct 16, 2014)

All of this is useless until the image quality itself improves, along with resolution, frame rates, and codecs.


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## Coldhands (Oct 16, 2014)

that1guyy said:


> All of this is useless until the image quality itself improves, along with resolution, frame rates, and codecs.



How do you figure? If this enables you to take that one special photo that would have otherwise been out of focus, then to me that's pretty useful.


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## Maximilian (Oct 16, 2014)

Lawliet said:


> Maximilian said:
> 
> 
> > I wouldn't have even thought about this beeing possible.
> ...


Yeah! But it is much easier to just do this to a wall with the same effect over one whole area.
The smart thing here is, that the camera must know by AF, aperture and much more data, which parts (!) of the area must stay clear (because in focus) and which must be blurred (because oof). 
Even with an EVF or live view screen this is tough. but with an in camera DSLR focussing screen...?
Just WOW!
(please correct me, if I get this patent wrong)


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## Coldhands (Oct 16, 2014)

Maximilian said:


> Lawliet said:
> 
> 
> > Maximilian said:
> ...



Unfortunately, I think you have misunderstood slightly. The screen isn't changing diffusion locally based on where the image is or is not in focus, it's changing the global diffusion. Think of it like the regular focus screen and the Super Precision Matte focus screen. The SPM screen has a higher diffusion, which makes it easier to visually distinguish between areas that are in or out of focus, but with the downside that it doesn't work well with slower lenses because it transmits less light. The tech in this patent essentially emulates the ability to instantaneously choose between a regular and SPM screen (and anything in between).


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## Lawliet (Oct 16, 2014)

Maximilian said:


> Yeah! But it is much easier to just do this to a wall with the same effect over one whole area.


You're not constrained to shade the wall uniformly - the more elaborte ones allow for sectional control, basicly a grayscale matrix display.


> Even with an EVF or live view screen this is tough. but with an in camera DSLR focussing screen...?


Take the focus mask from a Phase One and feed it into the display's control input.


> Just WOW!
> (please correct me, if I get this patent wrong)


Maybe I'd be more impressed hadn't our kindergardeners figured out how to entertain themselves during travel by playing a variation of "magna doodle" or the shadow theatre game on those seperators. ;D

The new part is just the use in the viewfinder, to replicate parts of the functionality an EVF has.


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## neuroanatomist (Oct 16, 2014)

In spite of the naysayers, this will be a very useful technology for anyone shooting with a mix of fast primes and slower lenses, and innovative of Canon to work toward a dSLR implementation of the technology.


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## Sporgon (Oct 16, 2014)

neuroanatomist said:


> In spite of the naysayers, this will be a very useful technology for anyone shooting with a mix of fast primes and slower lenses, and innovative of Canon to work toward a dSLR implementation of the technology.



Yes, photographers like me. I use fast primes but slow ( 24 to 300 range ) zooms, principally because I don't want to weigh myself down with heavy zoom lenses. The different screen characteristics required are a nuisance. It would be pleasing to have both in one.

My only concern is that is is going to be done with activating LCD, which in itself may not give the crisp clear screen view of current S screens when in focus.


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## vscd (Oct 16, 2014)

I use the Canon Ee-S and it's quite good to focus, even on f1.2. The downside is to use lenses with f2.8 or faster, but that's doable in most cases. Is the 5D Mark3 able to change the Focus Screens anyway? I don't think so... ;(


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## Joe M (Oct 16, 2014)

that1guyy said:


> All of this is useless until the image quality itself improves, along with resolution, frame rates, and codecs.


So shooting a fast prime is worthless right now as we don't have resolution, frame rates or codecs? I'm not sure I understand this. Why is being able to manually focus a fast prime of no value right now?


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## Mitch.Conner (Oct 16, 2014)

It just dawned on me, how useful will this be at night without some type of focusing screen illumination?


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## AcutancePhotography (Oct 16, 2014)

Mitch.Conner said:


> It just dawned on me, how useful will this be at night without some type of focusing screen illumination?



Probably no more or less of a problem than with a traditional Manual Focusing camera.


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## Maximilian (Oct 18, 2014)

Coldhands said:


> Maximilian said:
> 
> 
> > (please correct me, if I get this patent wrong)
> ...


Okay! I did (and still) read it a little bit different, but if it is so, it's still very nice but no longer "wow", that's true.
Thanks for giving me your interpretation.


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## Keith_Reeder (Oct 18, 2014)

Joe M said:


> So shooting a fast prime is worthless right now as we don't have resolution, frame rates or codecs? I'm not sure I understand this. Why is being able to manually focus a fast prime of no value right now?



_Don't feed the whiny troll..._

In fact, check out his Flickr stream and then tell me why we'd _give a toss_ about his "opinions":
http://www.flickr.com/photos/sidbphotos/


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## Mt Spokane Photography (Oct 24, 2014)

gbchriste said:


> And forgive my ignorance but why aren't modern DSLRs fitted with split prism focusing screens. I shot with a Canon AE-1 and/or A-1 for 20 years and never, ever missed focus on anything. I was 50/50 in focus with the 5DII and 70-200 2.8 Mk I. Now with the 5DIII and 70-200 MkII I'm about 90% in focus but still...


 
They are optional on 1 series. I bought one for my 1D MK III, but found that it really did not impress me in terms of improving my manual focus ability to the point where the results were as good as autofocus. Just my moving slightly forward or backwards would throw the focus off.

Third party focus screen sellers take the one series screens, and shave off the edges to fit other cameras. Sometimes they even cut down MF screens. Their markup is very high, cutting down a screen that they pay $10 - $15 for and selling it for hundreds of dollars.


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## Eldar (Oct 24, 2014)

Mt Spokane Photography said:


> Third party focus screen sellers take the one series screens, and shave off the edges to fit other cameras. Sometimes they even cut down MF screens. Their markup is very high, cutting down a screen that they pay $10 - $15 for and selling it for hundreds of dollars.


I bought an S-type screen equivalent for my 5DIII from www.focusingscreen.com (Taiwan) and paid less than USD100 for it. Made and delivered to Norway in less than 2 weeks. It is a lot better than the standard screen, for manual focus, but I have more success with the Ec-S mounted in my 1DX. But I believe some of that is due to the exceptional view finder of the 1DX. None of them are supported by the camera though and they both give a slightly unpredictable exposure. No compensation in some cases and -1EV in others, which both should have been +/-0.


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