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Archive 2011 · Canon patent for lens adapter

  
 
LightShow
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p.1 #1 · Canon patent for lens adapter


Canon patent for lens adapter, maybe for an EVIL camera?
you decide.

http://www.canonrumors.com/forum/index.php/topic,734.new.html


2nd diagram with communication contacts in a different location.



Mar 18, 2011 at 01:41 AM
douglasf13
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p.1 #2 · Canon patent for lens adapter


I hope not, because it looks like that'll mean the registration distance is too long for rangefinder lenses.


Mar 18, 2011 at 02:02 AM
edwardkaraa
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p.1 #3 · Canon patent for lens adapter


I guess you're right, Douglas, but what else can it be for? Canon may have adopted a slightly long registration to avoid the bad corners, perhaos it may even be FF?


Mar 18, 2011 at 02:37 AM
staticInc
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p.1 #4 · Canon patent for lens adapter


However, the adapter looks as if it wasn't designed for fast EF lenses. The inner diameter is much too small.


Mar 18, 2011 at 03:18 AM
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p.1 #5 · Canon patent for lens adapter


I agree, how is the 85L going to not vignette unless it's for a crop sensor.
I'm worried Canon's EVIL will be DOA, it may come down to ergonomics and native glass.
Then again, this is only a patent, not a finished product, things change.



Mar 18, 2011 at 09:33 AM
dasrocket
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p.1 #6 · Canon patent for lens adapter


The rear mount is smaller in diameter than the front mount; assuming the front is EF, the rear has to be a smaller format; which negates FF IMO.

One thing that I don't understand though is why there seem to be more contacts in the rear than the front. The new mount has more information IO-puts. 3Dmaybe??



Mar 18, 2011 at 10:20 AM
douglasf13
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p.1 #7 · Canon patent for lens adapter


edwardkaraa wrote:
I guess you're right, Douglas, but what else can it be for? Canon may have adopted a slightly long registration to avoid the bad corners, perhaos it may even be FF?


A long registration distance really doesn't have a corner advantage over a smaller one, like on NEX and m4/3, because you can just make the lenses on NEX and m4/3 as long as needed to improve the edges.

However, this could allow Canon to use a little visual trickery, by making very short, pancake lenses. People may say, "Look how tiny the Canon lenses are," when, in actuality, the registration distance+lens length will be a similar size to NEX. Samsung NX has done this to a lesser extent with their 25.5mm registration distance, so, in effect, they can make their lenses 7.5mm shorter than NEX with similar performance.

With all of the widely varying registration distances, it seems more prudent to take into account the total length of the system, measuring the front of the lens to the rear of the body, rather than just measuring the lenses themselves.



Mar 18, 2011 at 11:00 AM
alundeb
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p.1 #8 · Canon patent for lens adapter


dasrocket wrote:
The rear mount is smaller in diameter than the front mount; assuming the front is EF, the rear has to be a smaller format; which negates FF IMO.

One thing that I don't understand though is why there seem to be more contacts in the rear than the front. The new mount has more information IO-puts. 3Dmaybe??


Based on orientation of the lock pin relative to the contacts, the front is EF.

The rear pin layout is the same as on EF lenses that are compatible with teleconverters.



Mar 18, 2011 at 12:10 PM
JimBuchanan
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p.1 #9 · Canon patent for lens adapter


douglasf13 wrote:
I hope not, because it looks like that'll mean the registration distance is too long for rangefinder lenses.


I hope not, also, for that reason.

If the drawing is in fact an EF lens adapter for a shorter registration Canon body, and the 2 views are to scale with each other, I calculate a registration of 31mm for the new Canon camera.




Mar 18, 2011 at 12:18 PM
dasrocket
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p.1 #10 · Canon patent for lens adapter


alundeb wrote:
The rear pin layout is the same as on EF lenses that are compatible with teleconverters.


What information are the extra pins for since they do not transmit it from the lens?



Mar 18, 2011 at 12:43 PM
kakomu
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p.1 #11 · Canon patent for lens adapter


It looks like something designed for EF-S lenses. Maybe it's to convert EF-S lenses to EF mount?


Mar 18, 2011 at 01:07 PM
carstenw
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p.1 #12 · Canon patent for lens adapter


EF-S and EF lenses have the same register distance.


Mar 18, 2011 at 01:13 PM
alundeb
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p.1 #13 · Canon patent for lens adapter


dasrocket wrote:
What information are the extra pins for since they do not transmit it from the lens?


I am not 100% sure if I understand your question right, but the pins that don't exist on lenses not compatible with teleconverters are used for communication between the teleconverter and the lens. The teleconverter closest to the lens reports it's existence to the lens, and the lens modifies the content in the communication with the camera, the communication that runs over the common pins.

Since those extra pins exist on the rear side of the adapter, it can mean that Canon intend to make smaller and lighter teleconverters that will sit on the camera side of the adapter



Mar 18, 2011 at 01:14 PM
kakomu
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p.1 #14 · Canon patent for lens adapter


carstenw wrote:
EF-S and EF lenses have the same register distance.


EF-S lenses aren't compatible with full frame EF mounts. You have to modify an EF-S lens to fit on to a full frame EF mount.

Nevertheless, the narrow center opening seems to be in line with EF-S lenses. Also, note that side facing the lens has both the circle and square mount markers for EF and EF-S lenses, respectively, but the adapter itself only seems to have the spherical mount marker (EF).

There's no indication on this drawing, but maybe a glass element is meant to be placed in the center to allow EF-S to be focused to infinity on a full frame camera?

Edited on Mar 18, 2011 at 01:37 PM · View previous versions



Mar 18, 2011 at 01:32 PM
carstenw
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p.1 #15 · Canon patent for lens adapter


Yes, that is clear, but they have the same *register distance*, i.e. they need to be at the same distance from the sensor. It makes no sense to convert from one to the other, but have a thickness between lens and camera, because it won't be the right distance from the sensor.

It is almost certainly an EF-S AND EF adapter for some non-EOS camera potentially coming up.



Mar 18, 2011 at 01:36 PM
alundeb
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p.1 #16 · Canon patent for lens adapter


Just to avoid the usual confusion when looking at all those pins in the EF mount on both sides, for those not familiar with the EF mount:

The pins 440, 441 and 442 on the front side are power pins and are connected to the pins 420 and 421 on the rear side.



Mar 18, 2011 at 01:37 PM
alundeb
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p.1 #17 · Canon patent for lens adapter


alundeb wrote:
Just to avoid the usual confusion when looking at all those pins in the EF mount on both sides, for those not familiar with the EF mount:

The pins 440, 441 and 442 on the front side are power pins and are connected to the pins 420 and 421 on the rear side.


And "those" includes myself

Just realized that my previous answer doesn't make sense.



Mar 18, 2011 at 01:40 PM
kakomu
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p.1 #18 · Canon patent for lens adapter


On second look, the mount on the camera side is definitely smaller the EF. I wanted to say that it looks like 4/3, but the red sphere doesn't line up with the pins in the same way.


Mar 18, 2011 at 01:47 PM
dasrocket
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p.1 #19 · Canon patent for lens adapter


kakomu wrote:
EF-S lenses aren't compatible with full frame EF mounts. You have to modify an EF-S lens to fit on to a full frame EF mount.


I thought they were compatible, the problem being that the EFs lenses sit too far into the body to let a FF mirror flip.

While on this topic, am I correct n assuming that EFs lenses have a smaller image circle than FF? If so, they would physically fit but vignette a FF pelicle mirror DSLR??



Mar 18, 2011 at 02:18 PM
kakomu
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p.1 #20 · Canon patent for lens adapter


dasrocket wrote:
I thought they were compatible, the problem being that the EFs lenses sit too far into the body to let a FF mirror flip.


That's one problem. The other is that EF-S lenses are designed to be mechanically incompatible. You can't fit EF-S lenses into EF mounts that weren't designed for EF-S lenses. Note the section of hacking on this link: http://photonotes.org/articles/beginner-faq/lenses.html

The incompatibility with EF-S lenses was a problem with the 10D, D30 and D60 cameras.

dasrocket wrote:
While on this topic, am I correct n assuming that EFs lenses have a smaller image circle than FF? If so, they would physically fit but vignette a FF pelicle mirror DSLR??


It depends on the lens design. For instance, here's a link to hacking and putting a 10-22 lens on to a 1D https://www.fredmiranda.com/forum/topic/609503 Apparently, it fills the frame at 12mm.



Mar 18, 2011 at 02:28 PM
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