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#71
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Canned Air (Was One upmanship and Canon's claim)
On Sun, 8 Jul 2007 09:10:22 -0700, "MarkČ" mjmorgan(lowest even number
wrote: : Robert Coe wrote: : On Fri, 6 Jul 2007 23:16:46 -0700, "MarkČ" mjmorgan(lowest even : number wrote: : Peter A. Stavrakoglou wrote: : It's not advisable to use canned air to clear dust out of a DSLR, : especially on the sensor. : : The only problem with canned air is when you tip the can ... : : And so Mark passes up another opportunity to tell us how he made out : with his 1D3 at Canon's Irvine shop last week. I'm encouraged by : that. Mark wasn't at all reticent to say what he thought of the 1D3's : autofocus problem and Canon's initially passive reaction to it. His : silence now suggests to me that the folks at Irvine found a way to : ensure that the AF problem won't spoil his Africa trip. They would : almost certainly have asked him not to advertise it widely, lest all : 1D3 owners start beating down their door. : : Bob : : You'e good. -Except that there are still problems. I've wanted to type it : all out, but it will take some doing... Long story. Very interesting, : though. I'll try to do it today...though I'm REALLY struggling to be ready : in time for my flght tomorrow... Keep your priorities in order. We'll wait 'til you get back. Bob |
#72
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One upmanship and Canon's claim
Wolfgang Weisselberg wrote:
MarkČ mjmorgan@cox wrote: Carrying a handgun would drop me right into an ex-soviet prison... Be secure. Beware of other drivers. Invest into passive security. Never have to worry about bad streets or mud holes or finding no parking space. Never worry about the occasional firefight in the neighbourhood again. Make sure noone will steal your vehicle and escape unnoticed. Sleep asured, knowing that only very professional thieves can enter your vehicle --- and that the police will notice in time. Crush your competition completely. Drive a tank. APDS-ammo optional. -Wolfgang No worries... -This piece of camera gear will protect me... http://www.pbase.com/markuson/image/79464112/original -MarkČ -- Images (Plus Snaps & Grabs) by MarkČ at: www.pbase.com/markuson |
#73
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Canned Air (Was One upmanship and Canon's claim)
Robert Coe wrote:
On Sun, 8 Jul 2007 09:10:22 -0700, "MarkČ" mjmorgan(lowest even number wrote: Robert Coe wrote: On Fri, 6 Jul 2007 23:16:46 -0700, "MarkČ" mjmorgan(lowest even number wrote: Peter A. Stavrakoglou wrote: It's not advisable to use canned air to clear dust out of a DSLR, especially on the sensor. The only problem with canned air is when you tip the can ... And so Mark passes up another opportunity to tell us how he made out with his 1D3 at Canon's Irvine shop last week. I'm encouraged by that. Mark wasn't at all reticent to say what he thought of the 1D3's autofocus problem and Canon's initially passive reaction to it. His silence now suggests to me that the folks at Irvine found a way to ensure that the AF problem won't spoil his Africa trip. They would almost certainly have asked him not to advertise it widely, lest all 1D3 owners start beating down their door. Bob You'e good. -Except that there are still problems. I've wanted to type it all out, but it will take some doing... Long story. Very interesting, though. I'll try to do it today...though I'm REALLY struggling to be ready in time for my flght tomorrow... Keep your priorities in order. We'll wait 'til you get back. Bob Thanks. A good reminder, as I get far too carried away fiddling with doo-dads, etc., while my basics (clothes, etc.) remain un-packed... -- Images (Plus Snaps & Grabs) by MarkČ at: www.pbase.com/markuson |
#74
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One upmanship and Canon's claim
Roger N. Clark (change username to rnclark) wrote:
Alan Browne wrote: (and our cameras will be imaging spectrometers too). Oh, and make read and thermal noise zero. Boltzman says no-can-do. You could always add heat removal but it's unlikely that you can cool an entire portable camera sensor to milli-K levels. It need not violate any physics, I didn't say "violate" just that you need very low temps... and I should have said effectively zero, not absolutely. Read noise in the best consumer cameras is already under 4 electrons at room temperature and reports are reportedly even lower in the 1D Mark III. With more accurate 18-bit converters and on-pixel electronics, 1 electron read noise is possible. I was under the impression that absent very cold temps, that noise (thermal at least) is simply unavoidable. If 18 bits/channel is achieved and you throw away a couple/3 bits per channel for noise, then whatever is left should be quite clean indeed. Thermal noise keeps getting better with each generation sensor. Cooled CCDs reached the level of one electron/hour thermal dark current a long time ago, and DSLR CMOS dark currents are less than a thousand electrons/hour already at ambient temperatures (and noise is square root dark current). These are great values already, even without any improvements! Line and pixel uniformity is improving too with each generation, but is already outstanding. Most digital camera imaging has noise limited by photon noise, not other sources, so even with improvements, most images will see little difference. -- -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm -- [SI] gallery & rulz: http://www.pbase.com/shootin -- e-meil: Remove FreeLunch. |
#75
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Canned Air (Was One upmanship and Canon's claim)
In article ,
Robert Coe wrote: The only problem with canned air is when you tip the can ... No, that is one problem, the others are numerous. They include the fact that canned air can "spit" propellent at any time. Especially as the pressure in the can drops. Other problems include the fact that it is pressurized that is why some countries, like the USA, prohibit shipping it by air. Ground shipping only. Of course TSA does not want pressurized, sometimes flammable, gases on aircraft either. And then you, or others, can inhale the fumes - there have been recorded deaths among kids who do inhale the gas for a high. A good air blower like the Giottos has no pressurized gas in it, work at any angle, never run out of air, can't explode, can be shipped by air, do not proscribe any TSA regulations, have no flammable contents and put out as much pressure on average as a can of air over the can's usable life. And it is far less expensive in the long run since it does not run out of air and need replacement - unless you lose it. -- To reply no_ HPMarketing Corp. |
#76
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One upmanship and Canon's claim
Alan Browne wrote:
Roger N. Clark (change username to rnclark) wrote: Alan Browne wrote: (and our cameras will be imaging spectrometers too). Oh, and make read and thermal noise zero. Boltzman says no-can-do. You could always add heat removal but it's unlikely that you can cool an entire portable camera sensor to milli-K levels. It need not violate any physics, I didn't say "violate" just that you need very low temps... and I should have said effectively zero, not absolutely. Read noise in the best consumer cameras is already under 4 electrons at room temperature and reports are reportedly even lower in the 1D Mark III. With more accurate 18-bit converters and on-pixel electronics, 1 electron read noise is possible. I was under the impression that absent very cold temps, that noise (thermal at least) is simply unavoidable. If 18 bits/channel is achieved and you throw away a couple/3 bits per channel for noise, then whatever is left should be quite clean indeed. The noise is dependent on temperature, as well as capacitance and resistance. So instead of reducing temperature, for example, one could reduce one of the other parameters that determine noise. A good explanation with equations is he Concepts in Digital Imaging Technology CCD Noise Sources and Signal-to-Noise Ratio http://learn.hamamatsu.com/articles/ccdsnr.html (Hamamatsu is a sensor manufacturer.) Of course none of this is easy, as designs are quite mature. But that doesn't mean a new design won't come along that improves things. But since most images have noise dominated by photon noise, most people will see little difference. The main performance factors in digital cameras a pixel size, quantum efficiency (pretty much the same across current digital cameras). So we are down to pixel size as the major factor in performance at present. Of course the camera manufacturers don't want you to hear that. ;-) Roger |
#77
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One upmanship and Canon's claim
RichA wrote:
"Someone" posted that Canon said the new 1DMkIII has the finest images of an DSLR, even better than their current FF models. I do not know if this is true. But if it is, does it matter much? By Sept or so, a new 5D (7D) will be out and it will likely be the number one imager at that time. Then a new 1Ds will come out, and so on. Is there a point in stating something is "the best" only to have it usurped of it's title 4-6 months later? Why not just say that anything beyond 1.5 is going to produce exceptional images and it is the other features of the camera that should determine which one you buy, at least until something really exceptional comes along? So if that's the case why has Canon recalled the product? |
#78
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One upmanship and Canon's claim
On Sun, 08 Jul 2007 18:11:10 -0400, Spam THis dev/null wrote:
: RichA wrote: : "Someone" posted that Canon said the new 1DMkIII has the finest images : of an DSLR, even better than their current FF models. I do not know : if this is true. But if it is, does it matter much? By Sept or so, a : new 5D (7D) will be out and it will likely be the number one imager at : that time. Then a new 1Ds will come out, and so on. Is there a point : in stating something is "the best" only to have it usurped of it's : title 4-6 months later? Why not just say that anything beyond 1.5 is : going to produce exceptional images and it is the other features of : the camera that should determine which one you buy, at least until : something really exceptional comes along? : : So if that's the case why has Canon recalled the product? Have they? I don't see it mentioned on their Web site. There's a "product advisory" for the 1D3, but it has nothing to do with the autofocus problem. Bob |
#79
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One upmanship and Canon's claim
On Jul 8, 10:17 am, "Roger N. Clark (change username to rnclark)"
wrote: Scott W wrote: Roger N. Clark (change username to rnclark) wrote: I agree. I got my 1D Mark II in summer 2004, sometime after it was first introduced. It still works great, and at the moment better then 1D3's, and still has over half its original value, over 3 years later. The market has matured. Roger This is a good news bad news kind of thing. We bought a 20D 2 1/2 years ago and it is still a very capable camera and holds up very well to the 30D. So it is nice that the camera is not totally obsolete. The down side is that I can't buy a FF digital for $1500. In the early years the resolution of the cameras I bought went like this, 0.3 MP 1.2 MP 3.2MP and 8MP. Each time going up by a factor of well over 2, that trend ended in 2004, if it had not I would be shooting with a 24MP full frame camera right now and I would have paid about $1000 for it. I agree. I think there are two things limiting full frame prices: 1)no competition (Canon is it), and 2) cost of a wafer run is still very high. I remember seeing a figure that a 12-inch wafer run costs about $10,000 (if someone knows a better number, please let me know). So how many full-frame sensors fit on a 12-diameter disk (not many). Thus cost per sensor remains high. From one news report I saw, Canon refined the process to get far fewer defects per wafer, thus increasing yield. That allowed the 5D price to be so low. I can believe this, because a really good FF sensor (few flaws) would cost more than a 1DsMkII. As they do in industrial CCD cameras. That Canon is able to churn out working sensors in good numbers is lucky for users. |
#80
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One upmanship and Canon's claim
On Sun, 08 Jul 2007 19:56:18 -0700, RichA wrote:
I agree. I think there are two things limiting full frame prices: 1)no competition (Canon is it), and 2) cost of a wafer run is still very high. I remember seeing a figure that a 12-inch wafer run costs about $10,000 (if someone knows a better number, please let me know). So how many full-frame sensors fit on a 12-diameter disk (not many). Thus cost per sensor remains high. From one news report I saw, Canon refined the process to get far fewer defects per wafer, thus increasing yield. That allowed the 5D price to be so low. I can believe this, because a really good FF sensor (few flaws) would cost more than a 1DsMkII. Then you'll believe anything, but we already know that. Roger's $10,000 estimate is probably ball park accurate, as is Allen's estimate of somewhat less than 50 FF sensors per 12" wafer. If the final yield is only 40 FF sensors per wafer, the cost would be $10,000 / 40, or $250 per sensor. even if you quadruple the cost to take into account additional manufacturing costs and desired profits, you're not going to come close to the cost of a 1DsMkII. Or are you saying that the FF sensors that Canon puts into their cameras are the cheaper ones that have many flaws and that they really aren't very good? |
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