First Canon Mirrorless Related Patent?

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Jonathan,

For further reference, in US Patent application 2011/0052185 (in which the figures seem to be identical to that shown for the Japanese application), the text discusses that the difference between the flange back of the "new" body and the flange back of the "current" [EOS] body is equal to the "thickness" of the adapter, "C", of which they then say (with respect to Figure 2):

The thickness is a
distance in the direction of the optical axis from the camera
body side installation surface 31a to the lens side installation
surface 33a

Best regards,

Doug
 
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Hello dougkerr,

I meant that the inner portion ( where the screws are mounted) of the new mount side of the adapter, slightly protudes from the outer portion of the adapter (new mount side) àla or much like the canon FD lenses where the rear element portion of the lenses protudes and goes into the camera body.

http://www.mir.com.my/rb/photography/companies/canon/fdresources/fdlenses/85mm.htm


We don't have many informations about the new camera mount, toward the new camera body female bayonet.


Considering that Canon EOS and Canon FD flange back were expressed in millimeters and were exact numbers, respectively 44mm and 42mm; i guess it will be an exact number for the new mount too.

It means 12mm or 14mm for the adapter length.

* A 12mm adapter means that an APS-C size mirror box could fit, but in a very tight fit.
(I made measurement on my rebel, measuring the distance between the EF mount and the mirror at it uppest possition when it lays flat under the viewfinder with the Bulb mode. I've found a little less than 12mm, in reality something much close to 11.5mm.)
That's why i guessed the adapter could measure 12mm, i thought Canon would keep the mirror but i've realized in the patent that they won't.

So you're right, the most likely adapter length would be 14mm.

* A 14mm adapter means (as expressed in the patent) that an APS-C size mirror box won't fit at all.
=> It's really a mirrorless camera, because they mention the lack of a mirror and its associated Phase Detection AF device in the new mount.
Furthermore, we don't have any specs about sensor size. Without a mirror they would put anything they want. It could be Full Frame 24x36, Canon APS-H, APS-C size or even smaller than APS-C. After all the adapter is made for APS-C EFS lenses...so APS-C is the most likely.

From this point, we can say unanimously that new mount flange back distance will be exactly 30mm (44-14=30).

=> The new camera will NOT BE a kind of fusion between an EOS RT (OVF with fixed pellix mirror) and a small mirrorless camera such as a samsung nx, even with the addition of the OVF.
It could have been interesting for me, but some user at the time of the EOS RT repported the lack of incoming light and flare/ghosting issues due to pellix mirror. EOS RT wasn't a succes. I think that's why Canon doesn't want to do the same mistake again.

In fact, there is only one way to follow for Canon.
The mirrorless offering is already quite huge:
* Olympus/panasonic µ43
* Samsung NX
* Sony Nex
* The future Nikon mirrorless with 16mm diagonal length sensor (x2.7 crop factor)

After the huge enthusiasm around the Fuji X100 and the hard beginning of Sony nex (only 3 lenses available), i bet that Canon will release a RANGEFINDER APS-C based sytem !!!

A 30mm flange back is close to other RF flange back of the past such as Contax G&RF and Nikon RF...

http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

This new canon Digital RF sytems would sit right beetween high end compact camera (Canon G12) and bigger entry level DSLR (canon eos rebel/xxxd) in term of compactness.
For the price this won't be that simple...i let you imagine the price.
This new sytems could be a poor's man leica M RF competitor of the digital era (with liveview and AF). We could expect it would cost something between 1000~2000€.
 
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From the patent:

[0004]In response to the desire to decrease the size and weight of digital single reflex lens cameras, in recent years a new type of single lens reflex camera that differs from the conventional single lens reflex camera has been proposed. The new type of single lens reflex camera is not provided with a quick return mirror for guiding the imaging light flux to a viewfinder, and the flange back is shorter than that of a conventional camera. The new type of interchangeable lenses having a short flange back that is compatible with this new type of camera has been proposed. However, these new type of interchangeable lenses cannot easily handle a variety of photographic conditions because there are few models. Therefore, there are cases in which it is desirable to use in the new type of camera the conventional type of interchangeable lenses that have already been introduced to the market and for which there are ample models and quantities. Thus, a conversion adapter for connecting the conventional type of interchangeable lenses with the new type of camera body is necessary. The functions required of this conversion adapter generally include matching the differing mounting profiles of the lenses and the camera body, matching the differing flange backs of the lenses and the camera body, and not hindering the communication system between the lenses and the camera body.
 
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Not that it matters much, but I have spoken of the flange back for the Micro Four Thirds system as "20 mm", whereas I see it often described as "about 20 mm" (no definitive value being cited).

There is a report from a fellow who, from a a T mount-to-Lumix DMC-G1 adapter, concludes that the Micro Four Thirds flange back is likely about 19.2 mm (recognizing that the adapter might have an offset for "safe infinity focus" built in, so perhaps the actual nominal flange back is a little larger than that).

Thus it might be that the nominal flange back for the Micro Four Thirds system is exactly half that for the Four Thirds system (which has been stated as 38.67 mm), or 19.33 mm.

Best regards,

Doug
 
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Jonathan said:
Hello,
I've found an interesting rumor from June.

http://photorumors.com/2010/06/09/canon-aps-h-1-3x-mirrorless/

Now, it seems pretty plausible after that mirrorless patent came out.
Might make sense.

The EOS line has to date had three nominal frame sizes. It might be that the New Canon Thing (NCT) would also embrace bodies of differing format size, with something like 27 x 18 mm (32.44 mm image circle requirement) being the largest (0.75 of full-frame 35-mm format).

Then the "smaller" bodies might in fact have the rumored 18 x 12 mm format (0.50 of full-frame 35-mm format).

That would be a 3:2 ratio between the format sizes in the family, probably a sensible spread.

I have made no attempt to ascertain the design limits relating image circle to to such things as mount throat and back flange distance, so I'm in no position to opine on the design credibility.

You earlier suggested that you believe the mount implied by the patent would not support a frame size larger than what you call "APS-C" (by which I assume you don't actually mean the APS-C frame size but rather the Canon "1.3x" frame size often spoken of as "APS-C", perhaps nominally 22.3 x 14.9 mm). (The APS-C frame is 23.4 mm x 16.7 mm.)

Best regards,

Doug
 
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dougkerr said:
You earlier suggested that you believe the mount implied by the patent would not support a frame size larger than what you call "APS-C" (by which I assume you don't actually mean the APS-C frame size but rather the Canon "1.3x" frame size often spoken of as "APS-C", perhaps nominally 22.3 x 14.9 mm). (The APS-C frame is 23.4 mm x 16.7 mm.)

Best regards,

Doug

Doug, I think you have a Typo in there, 1.3X crop APS-H is about 27.9 X 18.6 (1D MK IV) while 1.6X crop APS-C runs about 22.3 X 14.9.
 
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scalesusa said:
Doug, I think you have a Typo in there, 1.3X crop APS-H is about 27.9 X 18.6 (1D MK IV) while 1.6X crop APS-C runs about 22.3 X 14.9.
No, I was speaking of the actual APS-C frame size, not the various digital camera frame sizes that are somewhere in that neighborhood and are often spoken of as "APS-C".

The APS taken frame size is 30.2 mm x 16.7 mm.

There are three "delivery crop" frames standardized:

APS-H: 30.2 mm x 16.7 mm (1.808:1) (this is in fact the taken frame size).
APS-C: 23.4 mm x 16.7 mm (1.401:1)
APS-P 30.2 mm x 9.5 mm (3.179:1)

Best regards,

Doug
 
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My apologies. I was in fact in error regarding the APS-C frame size (I picked the numbers up from an old table that I had somehow screwed up, without looking at it).

Here is the correct info:

The APS taken frame size is 30.2 mm x 16.7 mm.

There are three "delivery crop" frames standardized:

APS-H: 30.2 mm x 16.7 mm (1.808:1) (16:9 would be 1.778:1) [this is in fact the taken frame size - it is "full frame"]
APS-C: 25.1 mm x 16.7 mm (1.503:1) (3:2 would be 1.500:1)
APS-P 30.2 mm x 9.5 mm (3.179:1)

Sorry for the error.

Using the "full-frame 35-mm equivalent focal length factor" convention, an actual APS-C frame size (not found, within 5%, in any digital cameras I know of) would be considered "1.44x".

So it's probably not a bad metaphor for such frame sizes as 22.3 x 14.9 mm ("1.61x" - EOS 60D) and 27.9 x 18.6 mm ("1.29x" - EOS 1D Mark IV).

Oh, wait - they call the latter of those sizes "APS-H". Well, that's actually 30.2 x 16.7 mm. So it would better to call the 1D4 size "APS-C".

Glad I don't have to decide that.

Who does get to decide that?

As for me, I use "APS-C" to mean "APS-C".

Best regards,

Doug
 
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Jonathan said:
If you have seen the diagram you would immediately understand that the new mount can only support APS-C format sensor.

This diagram?

No dimensions, and no requirement to draw it to any particular scale.

From this, you can determine the sensor coverage? I see no information about the lenses, they are what determines coverage, nothing else.
 
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scalesusa said:
This diagram?

No dimensions, and no requirement to draw it to any particular scale.

True, but the "front" face exactly matches in proportions every feature of an EOS mount. Thus, if it the rest of it is drawn to the same scale, we can determine that scale to a high precision.

From this, you can determine the sensor coverage? I see no information about the lenses, they are what determines coverage, nothing else.

Yes but there is an interaction with the mount throat diameter.

If in fact the lens design places the exit pupil at the mount throat (hard to do and not necessarily desirable from several standpoints), then the throat does not constrain the image circle. For an exit pupil forward of that, the mount throat does constrain the image circle.

Best regards,

Doug
 
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dougkerr said:
Jonathan said:
Hello,
I've found an interesting rumor from June.

http://photorumors.com/2010/06/09/canon-aps-h-1-3x-mirrorless/

Now, it seems pretty plausible after that mirrorless patent came out.
Might make sense.

The EOS line has to date had three nominal frame sizes. It might be that the New Canon Thing (NCT) would also embrace bodies of differing format size, with something like 27 x 18 mm (32.44 mm image circle requirement) being the largest (0.75 of full-frame 35-mm format).

I have made no attempt to ascertain the design limits relating image circle to to such things as mount throat and back flange distance, so I'm in no position to opine on the design credibility.

Best regards,

Doug

I'm pretty agree with you.
The new "NCT" might be a kind of a new EF-C (compacted or a EF "downsized").

If we look at the proportion, the new flange back distance (30mm) vs EF flange back distance (44mm), is approximately 70 percent of the actual EF flange back (30/44=0.68).

The sensor surface of an APS-C(x1.6) is ALSO 70 percent of an APS-H sensor surface.
APS-H size (in millimeters) : 27.9mm*18.6mm= 518.94 squarred millimeters
Canon APS-C size: 22.3mm*14.9mm=332.27 squarred millimeters

APS-C/APS-H ratio = 332.27/518.94 =0.64

It means, that we can consider these new system as a mirroless EOS sytems in reduction, with a reduction factor of 30%.
It also means, new lenses, design for an APS-H (33.53mm image circle) coverage, smaller than EF Full Frame lenses of at least 30%.
For example can you imagine a 24-70mm F/2.8 L equivalent, that would measure 85mm in length and 58mm in diameter instead of 123.5mm (length) and 86.45mm (diameter) with the same performance and even lighter?? ::)

IMHO the APS-H (x1,3) is the first choice for this new mount, at least for the high-end, RF style (with EVF or hybrid), pro bodies.
Thus EF-S lenses + adapter would work on a cropped mode (~70% of available pixel).
It would give 10.3Mp from the actual 16.1 APS-H sensor of the 1D mk4. It's not the best, but it's quite acceptable (remember that it would be the only solution to recycle EF-S lenses, in the other hand it would not be the optimal use of the new mount abilities and it would help Canon to sell new mounted lenses and existing "FF" L lenses).

At the lower-end, canon has just to keep actual APS-C sensor for this new mount, and make "Samsung NX" alike bodies with built-in EVF or something with pellix.

I don't believe in the introduction of a smaller than APS-C sensor, a 18*12 sensor doesn't make sense at all with such a flange back, unless they keep a mirrorbox, but they won't and it already exists ( Olympus E-volt DSLR series, such as the e-620).
Plus Canon would put some money in R&D for a new type of smaller sensor. They don't need to do this, they already have all the materials and technology to create a new mount almost effortless.
And who cares about the aspect ratio in the entry-level consumer range ?? There's already Samsung nx and nex against 4/3, plus with APS-C (x1.5) (slightly bigger than those of Canon).

Best regards,

Jonathan
 
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Hi, Jonathan,

Interesting observations.

I'm not sure how matters of sensor area fit into the thought process.

It is interesting to note that, among all the existing SLR-based still camera systems (that I have data for), the flange back distance is never less than 0.94 times the diagonal of the maximum system frame size (typically 43.26 mm, based on full-frame 35-mm as the "mother" size), and (if we exclude the "T-mount", not actually a camera system) is never greater than 1.09 times the mother frame diagonal.

If we think of the New Canon Thing having a "mother" frame size of 28 x 18.5 mm ("1.29x"), as some have speculated, then for the 30.0 mm flange back speculated upon here, that ratio would be 0.89.

That would not necessarily rule out a bona fide SLR version of the system, but it might be iffy.

Best regards,

Doug
 
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dougkerr said:
Hi, Jonathan,

Interesting observations.

I'm not sure how matters of sensor area fit into the thought process.

It is interesting to note that, among all the existing SLR-based still camera systems (that I have data for), the flange back distance is never less than 0.94 times the diagonal of the maximum system frame size (typically 43.26 mm, based on full-frame 35-mm as the "mother" size), and (if we exclude the "T-mount", not actually a camera system) is never greater than 1.09 times the mother frame diagonal.

If we think of the New Canon Thing having a "mother" frame size of 28 x 18.5 mm ("1.29x"), as some have speculated, then for the 30.0 mm flange back speculated upon here, that ratio would be 0.89.

That would not necessarily rule out a bona fide SLR version of the system, but it might be iffy.

Best regards,

Doug

Interesting, but those ratios can only be applied to standard SLR (with a mirror-Box). Plus FD flange was 42mm, less than 43.26.
The new system is MIRRORLESS, so this rule doesn't make sense.

And Mirrorless allows optical engineers more freedom in their designs, especially for wide compact prime (the rear element could protudes and goes deeper in the body cavity).

An extrem mounting of a wide lens to give you an example:
http://www.16-9.net/lens_tests/15mm_test1.html
 
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Hi, Jonathan,

Jonathan said:
Interesting, but those ratios can only be applied to standard SLR (with a mirror-Box).

Is there an SLR without a mirror-box?

Plus FD flange was 42mm, less than 43.26.

Yes, a ratio of 0.97 (I said "never less than 0.94").

The new system is MIRRORLESS, so this rule doesn't make sense.

I don't know that the New Canon Thing system will not admit models with a bona-fide SLR viewing mode. (Maybe you do.)

Best regards,

Doug
 
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The new system is MIRRORLESS, so this rule doesn't make sense.

I don't know that the New Canon Thing system will not admit models with a bona-fide SLR viewing mode. (Maybe you do.)

Best regards,

Doug

Maybe there will be models with OVF, but it would be either with the help of a RF style OVF or a traditional OVF via a semi-transparent mirror (like the EOS RT).

Best regards, Jonathan
 
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