46
Canon General / Re: APS-C 11mm f/2 Patent
« on: April 06, 2011, 03:43:39 PM »thank you for hitting my typo…..Le crayon rouge ne dort jamais!
Best regards,
Doug
May 25, 2013, 07:35:56 AM
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Best regards,
Doug
47
Canon General / Re: APS-C 11mm f/2 Patent
« on: April 06, 2011, 03:39:15 PM »
This patent is for a projection lens for an LCD-based video projector.
The corresponding US patent application is 2011/0038054.
Thanks to my colleague Hans Jørgensgaard for making the connection on this (he is my "go-to guy" on Canon patents)..
Best regards,
Doug
The corresponding US patent application is 2011/0038054.
Thanks to my colleague Hans Jørgensgaard for making the connection on this (he is my "go-to guy" on Canon patents)..
Best regards,
Doug
49
Software & Accessories / Re: Thoughts on 430EX
« on: March 25, 2011, 11:53:55 AM »Thanks for dropping all this knowledge on us. You are a true asset to the CR forum community.Thank you so much. I find this forum very useful to my own interests.
Best regards,
Doug
50
Software & Accessories / Re: Thoughts on 430EX
« on: March 25, 2011, 11:23:02 AM »
Chuck Westfall of Canon USA has recently advised of a correction to his original summary of the circumstances in which the Speedlite 430EX (and 430EX II) flash units may operate in the multi-flash ("stroboscopic") mode.
He had originally said that the units could operate in that mode only when operating as a slave and the master is a Speedlite 550EX, 580EX, or 580EX II or the onboard flash unit of an EOS 7D.
He now advises that he has determined that in fact the multi-flash mode cannot be utilized by way of the onboard flash unit of an EOS 7D as a master. When that facility is set to the multi-flash mode, its operation as a master is disabled.
Thus, the Speedlite 430EX (or 430EX II) can only operate in the multi-flash mode when operating as a slave and the master is a Speedlite 550EX, 580EX, or 580EX II.
Again, to avert any misunderstanding, the 430EX (or 430EX II) apparently cannot provide the multi-flash mode when being directly operated from any camera, whether or not that camera provides for setting the associated flash.
Chuck's recent notice is here:
http://www.prophotohome.com/forum/canon-1-series-digital-slr-eos-5d/96337-speedlite-430ex-multi-flash-mode-chuck-2.html#post488749
Best regards,
Doug
He had originally said that the units could operate in that mode only when operating as a slave and the master is a Speedlite 550EX, 580EX, or 580EX II or the onboard flash unit of an EOS 7D.
He now advises that he has determined that in fact the multi-flash mode cannot be utilized by way of the onboard flash unit of an EOS 7D as a master. When that facility is set to the multi-flash mode, its operation as a master is disabled.
Thus, the Speedlite 430EX (or 430EX II) can only operate in the multi-flash mode when operating as a slave and the master is a Speedlite 550EX, 580EX, or 580EX II.
Again, to avert any misunderstanding, the 430EX (or 430EX II) apparently cannot provide the multi-flash mode when being directly operated from any camera, whether or not that camera provides for setting the associated flash.
Chuck's recent notice is here:
http://www.prophotohome.com/forum/canon-1-series-digital-slr-eos-5d/96337-speedlite-430ex-multi-flash-mode-chuck-2.html#post488749
Best regards,
Doug
51
EOS Bodies / Re: First Canon Mirrorless Related Patent?
« on: March 23, 2011, 01:55:01 PM »
Hi, Jonathan,
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
... 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
52
EOS Bodies / Re: First Canon Mirrorless Related Patent?
« on: March 23, 2011, 01:37:04 PM »
Hi, Jonathan,
Is there an SLR without a mirror-box?
Yes, a ratio of 0.97 (I said "never less than 0.94").
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
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
53
EOS Bodies / Re: First Canon Mirrorless Related Patent?
« on: March 23, 2011, 01:31:42 PM »
Hi, Jonathan,
Thanks.
Best regards,
Doug
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
54
EOS Bodies / Re: First Canon Mirrorless Related Patent?
« 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
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
55
United States / Re: 7d
« on: March 23, 2011, 12:50:48 PM »Given the same focusing distance, depth-of-field will not change.That's not necessarily true. The reckoning of depth of field is based, among other things, on an arbitrary criterion we choose, the circle of confusion diameter limit (COCDL). This is the largest diameter of the blur circle resulting from imperfect focus of objects not at the ideal focus distance that we, based on some outlook, are willing to consider "acceptable".
We may use many premises to choose a value of that. One traditional premise is as a certain fraction of the frame diagonal size. The concept behind this a fixed angular size of the "blur circle" when the image itself is viewed with a consistent angular size, for example, printed to a certain size and viewed from a certain distance.
If we follow that premise, then for a camera with a "smaller format", with a certain focal length lens, a certain f-number, and a certain distance to the subject, the calculated DoF will be smaller than for the larger-format camera - not because anything has changed in the optical physics but rather because our criterion of acceptable blur is changed for the new format size.
Quote
Given the same framing, depth-of-field will be greater on the 7D because your focusing distance will be greater (due to the crop factor, you'll have to back up)Indeed.
But it is interesting to see how that happens. Two factors are at work.
Firstly, if we indeed hold to the choice of a COCDL that is a fixed fraction of the fame size, then, for a "smaller" frame size, that factor of itself will decrease the calculated DoF.
However, as you point out, to maintain the original framing, the needed distance to the subject will increase. This increases the calculated DoF, and by a greater ratio than it is diminished by the adoption of a smaller COCDL. Thus, the net effect is indeed an increase in the DoF.
Best regards,
Doug
56
EOS Bodies / Re: First Canon Mirrorless Related Patent?
« 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
57
EOS Bodies / Re: First Canon Mirrorless Related Patent?
« on: March 22, 2011, 05:14:41 PM »
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
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
58
EOS Bodies / Re: First Canon Mirrorless Related Patent?
« on: March 22, 2011, 04:19:36 PM »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".
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.
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
59
Canon General / Re: Canon falling behind in sensor performance
« on: March 22, 2011, 03:32:22 PM »Sony has developed and implemented complex algorithms into their latest Exmor sensor.
I'm not sure what kind of algorithms there are in sensors. Sensor systems, maybe.
Best regards,
Doug
60
EOS Bodies / Re: First Canon Mirrorless Related Patent?
« on: March 22, 2011, 01:19:14 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).
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