October 23, 2014, 04:40:25 AM

Author Topic: First Canon Mirrorless Related Patent?  (Read 18671 times)

CR Backup Admin

  • Administrator
  • 1D Mark IV
  • *****
  • Posts: 797
    • View Profile
Re: First Canon Mirrorless Related Patent?
« Reply #30 on: March 22, 2011, 08:02:36 PM »
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.

canon rumors FORUM

Re: First Canon Mirrorless Related Patent?
« Reply #30 on: March 22, 2011, 08:02:36 PM »

dougkerr

  • Rebel SL1
  • ***
  • Posts: 85
    • View Profile
    • The Pumpkin
Re: First Canon Mirrorless Related Patent?
« Reply #31 on: March 22, 2011, 10:42:48 PM »
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.

Quote
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

Jonathan

  • Guest
Re: First Canon Mirrorless Related Patent?
« Reply #32 on: March 23, 2011, 12:31:51 PM »
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
« Last Edit: March 23, 2011, 12:37:29 PM by Jonathan »

dougkerr

  • Rebel SL1
  • ***
  • Posts: 85
    • View Profile
    • The Pumpkin
Re: First Canon Mirrorless Related Patent?
« Reply #33 on: March 23, 2011, 01:03:03 PM »
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

Jonathan

  • Guest
Re: First Canon Mirrorless Related Patent?
« Reply #34 on: March 23, 2011, 01:29:12 PM »
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

dougkerr

  • Rebel SL1
  • ***
  • Posts: 85
    • View Profile
    • The Pumpkin
Re: First Canon Mirrorless Related Patent?
« Reply #35 on: March 23, 2011, 01:31:42 PM »
Hi, Jonathan,

Thus EF-S lenses + adapter would work on a cropped mode. . .
Always nice to see "cropped" used correctly (not to mean "smaller than something else we often think about").

Thanks.

Best regards,

Doug

dougkerr

  • Rebel SL1
  • ***
  • Posts: 85
    • View Profile
    • The Pumpkin
Re: First Canon Mirrorless Related Patent?
« Reply #36 on: March 23, 2011, 01:37:04 PM »
Hi, Jonathan,


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

Is there an SLR without a mirror-box?

Quote
Plus FD flange was 42mm, less than 43.26.

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

Quote
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
« Last Edit: March 23, 2011, 01:51:38 PM by dougkerr »

canon rumors FORUM

Re: First Canon Mirrorless Related Patent?
« Reply #36 on: March 23, 2011, 01:37:04 PM »

Jonathan

  • Guest
Re: First Canon Mirrorless Related Patent?
« Reply #37 on: March 23, 2011, 01:46:25 PM »
If you'll want a bona-fide SLR viewing mode, i'm pretty sure that the EOS System will continue to exist, at least for Pro's so you know what to do.   ;)

Jonathan

  • Guest
Re: First Canon Mirrorless Related Patent?
« Reply #38 on: March 23, 2011, 01:50:02 PM »
Quote
Quote
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
« Last Edit: March 23, 2011, 02:09:07 PM by Jonathan »

dougkerr

  • Rebel SL1
  • ***
  • Posts: 85
    • View Profile
    • The Pumpkin
Re: First Canon Mirrorless Related Patent?
« Reply #39 on: March 23, 2011, 01:55:01 PM »
Hi, Jonathan,

... or a traditional EVF via a pellix mirror.

What would that mean?

In any case, you perhaps speak of a pellicle mirror ("Pellix" is the name of a camera model)..

Best regards,

Doug

Jonathan

  • Guest
Re: First Canon Mirrorless Related Patent?
« Reply #40 on: March 23, 2011, 02:09:47 PM »
Sorry it was a mistake in typography.  ;)
Best regards.

Jonathan

  • Guest
Re: First Canon Mirrorless Related Patent?
« Reply #41 on: March 23, 2011, 02:36:17 PM »
 For me MIRRORLESS means every camera without slapping, full reflective mirror.

Fixed Semi-reflective mirror camera still have a mirror,  so it could be named SLR, but it is more an hybrid construction between mirrorless and conventional SLR with a quick return mirror.

Plus the patent clearly shows (in section 0015) that "a quick return mirror and a dedicated focal point detection unit are not provided in the camera body."

=> No mirror at all
or
=> Fixed pellicle mirror with either an OVF (like eos RT) or with an EVF (like Sony Translucent, SLT slr)

Best regards,

Jonathan

canon rumors FORUM

Re: First Canon Mirrorless Related Patent?
« Reply #41 on: March 23, 2011, 02:36:17 PM »