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Comments

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Can You Tell the Difference? 4K Galaxy Note 3 vs. Canon 5D Mark III Video

asvravi Re:Counter rate (201 comments)

I think he means the photon detector itself, not the actual counter. The detector needs a cool off or reset period before it is ready for the next photon. This can easily be of the order of several 10's of ns.

about 5 months ago
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Can You Tell the Difference? 4K Galaxy Note 3 vs. Canon 5D Mark III Video

asvravi Re:DOF (201 comments)

A whole lot of hogwash in here - wrong units, dimensionally inconsistent equations, plain ridiculous or missing assumptions but still the post gets modded as insightful just because it *sounds* insightful.

- Larger pixels improve dynamic range. DR is defined as max signal before pixel saturation, divided by noise. Noise is limited by shot noise and electronics so does not scale with pixel size. Larger pixels have more signal range. So DR is higher.
- You calculate DR as if there is only one electron noise. Try several magnitudes higher noise! I am not sure DR is what you think it is.
- QE for most sensors is between 20% and 50%. 10% is nonsense.
- ISOCELL improves color rendition, it has nothing to do with sensitivity.

Following from Samsung should help -


According to Samsung, the ISOCELL sensor design achieves better image quality than is normally possible from the very small CMOS sensors used in smartphones and tablets. ISOCELL uses a backside-illuminated (BSI) photodiode that is unique compared to past designs thanks to its integrated barriers between the individual pixels. Compared to conventional BSI sensors, this reduces electrical crosstalk by about 30 percent. Crosstalk - the bleeding of photons and photoelectrons between neighboring pixels - has been a disadvantage of traditional BSI sensor design, one that can reduce image sharpness and color accuracy because light intended for one particular pixel spreads to its neighbors.

Existing BSI designs, with their photodiodes near the front of the sensor, lack any inherent structures that prevent light bleeding between pixels (a role fortuitously played by the circuitry in front of the photodiodes in older, frontside-illuminated chips). The barriers in the ISOCELL design prevent this bleeding.

How do you equate 10% QE to 5pLumens/pix "sensitivity"? I am not sure Sensitivity is what you think it is. Sensitivity is defined as voltage output from the sensor for a given light input. What is the voltage output assumed here? How does it compare to the camera noise?

Given this, rest of your statements do not make any sense either. When you say "generous" assumptions, it turns out they are actually ridiculous assumptions - you have removed the entire point of analysis and pixel size and even ignored reality, which is what the OP is commenting about. You disagreed with his points that are based on solid reality, but then ended up giving a half-baked proof derived from supposedly "fundamental" limits that are nowhere close to reality.

about 5 months ago
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Sony Tape Storage Breakthrough Could Bring Us 185 TB Cartridges

asvravi Re:Nostalgia (208 comments)

Not so fast! They still haven't perfected slipstream of rootkits onto Vinyl.

about 5 months ago
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Sony Tape Storage Breakthrough Could Bring Us 185 TB Cartridges

asvravi Re:But is it even usable? (208 comments)

Periodically you swap over to a new tape.

Every 180 years to be precise. Your bigger problem would be material rot, assuming you would want anything more than a couple of decades worth of backup.

about 5 months ago
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Graphene-Based Image Sensor To Enhance Low-Light Photography

asvravi Re:1000 times better? (103 comments)

First off, if we cut through the usual dismal quality of scientific reporting, what they made is a photodetector, not an image sensor. It detects single events rather than capture an image. The sensitivity of the detector is not the same as quantum efficiency. The sensitivity they mention here includes a "photogain" by virtue of the detector operating more or less as a light-controlled amplifier. It takes electrical input energy and simply amplifies it based on incident light. That can create a flow of many more electrons than incident photons. The same thing can possibly be also done by introducing a gain in the conventional image sensor electronics too, but having this photogain right inside the sensor should theoretically lead to better noise performance. So we would expect the paper to quantify the noise characteristics, but it is woefully sparse on the noise details - which leads me to suspect this is yet another "invention" that is never going to see the light of day.

about a year ago
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Indian Gov't Bans Bulk SMS, Investigating Social Media

asvravi Re:And... (101 comments)

Sanest comment on this post yet! Wonder why it is not marked +5 insightful yet..

more than 2 years ago
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Monsanto May Have To Repay 10 Years of GM Soya Royalties In Brazil

asvravi Re:Remove the yoke of Monsanto! (377 comments)

Wrong on the India farmers bit. Here is an extract from a Wikipedia article -

There have been claims of genetically-modified (GM) seeds (such as Bt cotton) being responsible for the farmer suicides.[25][26][27][28] A short documentary by Frontline (U.S. TV series) suggested that farmers using GM seeds promoted by Cargill and Monsanto have led to rising debts and forced some into the equivalent of indentured servitude to the moneylenders.[29]
A report released by the International Food Policy Research Institute in October 2008 provided evidence that the introduction of Bt cotton was not a major factor in farmer suicides in India.[30] It argues that the suicides predate the introduction of the cotton in 2002 and has been fairly consistent since 1997.[30][31] Other studies also suggest the increase in farmer suicides is due to a combination of various socio-economic factors.[32] These include debt, the difficulty of farming semi-arid regions, poor agricultural income, absence of alternative income opportunities, the downturn in the urban economy forcing non-farmers into farming, and the absence of suitable counseling services.[32][33]

more than 2 years ago
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The Dutch Repair Cafe Versus the Throwaway Society

asvravi Ignore (368 comments)

Posting to remove unintentional mod.

more than 2 years ago
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Ask Slashdot: How to Exploit Post-Cataract Ultraviolet Vision?

asvravi Re:Dangerous (350 comments)

No they aren't safe. In the case of sunlight, eyes see it pretty strongly and the pupils contract to cut down the amount of light that strikes the retina thus protecting it. In case of UV, there is a chance he may not see a part of the spectrum so his pupils remain dilated letting in dangerous amounts of UV light. Same reason it is advised to never look at an eclipse with unprotected eyes.

more than 2 years ago
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Mozilla Lightning Calendar Nears 1.0

asvravi Re:freezes for several seconds (69 comments)

Syncs in background for me, I dont have this issue. If it happens only when you are writing an email, then you probably configured your drafts to be saved to a (slow) IMAP folder?

more than 2 years ago
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Smartphones: the New Home of Crapware

asvravi Re:2 Words (308 comments)

Still waiting for the second word...

about 3 years ago
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Dismantling a Nuclear Reactor

asvravi Re:In this thread... (102 comments)

Why isn't this in Ask Slashdot section??

more than 3 years ago
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Understanding the Payoffs From Investing In Space Flight

asvravi Re:Intel didn't start until 1968 (264 comments)

Space programs do not drive the fundamental tech needed for smartphones - they may contribute to advancing ruggedness and reliability of electronics, but never miniaturization or cost reduction. NASA would prefer to use a tried and tested FPGA that is 20 years old, in a 1um radiation hardened process, rather than the latest 40nm Nvdia/Qualcomm processors, leave alone driving their development.

more than 3 years ago
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Google+ Runs Out of Disk Space, Swamps Users With Notifications

asvravi Re:Google+ (321 comments)

You sure do not have an account, or, what is it that you are smoking? There is a prominent checkbox to opt out of data collection for targeted advertising right on the initial login form, even before starting to signing up for Google+. They also display your profile settings for the first time after signing up, where you get a chance to change anything you want before it goes live.

Somebody please mod this FB shill a troll...

more than 3 years ago
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Ask Slashdot: Open Patent Licenses?

asvravi Publish? (96 comments)

So why not just publish it, making it prior art? Or maybe what you want are Trade Secrets?

more than 3 years ago
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Microsoft Brands WebGL a 'Harmful' Technology

asvravi Re:Microsoft should know... (503 comments)

I agree. MS has become increasingly security savvy to protect their main business - the OS and the Office applications that go on it. The Vista/Win7 permissions model, MS Anti-malware updates, MS Security Essentials, Driver signing, bug bounties, are all examples of MS efforts to up the security. These comments are along expected lines from MS in this age. (And no, I use more Linux than Windows, but credit to be given where credit is due).

more than 3 years ago
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China Building World's Biggest Radio Telescope

asvravi Re:It's been awhile since astro classes, but... (121 comments)

Photons? For a RADIO telescope?? Yes, quite a while since your astro classes.

The SNR you quote, which improves as square root of the collected radiation (radio waves), is voltage SNR. In terms of power, you still get a 9dB SNR improvement for 3 times the collected radio waves, and in these electronics, it is electric power which is the ultimately used. However, the improvement factor should again be raised to power 1/3 to get distance, since the amount of signal power collected by an aperture, after spherical dispersion from a star, drops as the third power of the star's distance. So.. (25/9)^(1/3) = 1.4 times.

more than 3 years ago

Submissions

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Extending human vision range into near-infrared with Vitamin A

asvravi asvravi writes  |  about a month ago

asvravi (1236558) writes "A crowd-funded experiment on experiment.com seeks to extend the color range of human vision into near infra-red by only manipulating the amounts of vitamin A1 and A2 in the diet of subjects.
https://experiment.com/project...
It has now reported initial success with human eye response at 950nm as compared to 850nm before the diet modifications. https://experiment.com/u/aAcR2...
How long until full night vision?"
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Intellectual Ventures LLC wins Lawsuit against Canon; Settles with Xilinx

asvravi asvravi writes  |  about 4 months ago

asvravi (1236558) writes "Reuters has news of Intellectual Ventures' Lawsuits against Xilinx — http://www.reuters.com/article...

Patent owner Intellectual Ventures has settled a lawsuit against one of its own investors, chipmaker Xilinx, a case that had been closely followed by advocates seeking to change the U.S. patent system. ... Chipmaker Xilinx invested in two Intellectual Ventures funds and licensed a portion of IV's patents, but resisted IV's entreaties to license more patents in 2010, court filings show. Xilinx eventually asked a California federal judge to declare those IV patents invalid, while IV countersued in Delaware, accusing Xilinx of infringement.

More details of the Canon case are over a Image Sensors World — http://image-sensors-world.blo... and http://image-sensors-world.blo...

Intellectual Ventures reports that the U.S. District Court for the District of Delaware rendered a verdict finding two Intellectual Ventures’ (IV) image sensor patents valid and infringed by digital camera products of Canon Inc. and Canon USA. Law360.com adds that "the jury held that Canon’s EOS 1DS Mark III, EOS 5D Mark II and Vixia Camcorders infringe at least one claim of U.S. Patent Number 6,023,081, which Canon failed to invalidate for obviousness."

In one account, Intellectual Ventures has been reported to operate out of 3200 shell accounts to either intimidate or protect industry players making use of a broken US patent system. It has raised about $6 Billion and has amassed a vast portfolio of 70,000 patents and counts many of the biggest consumer industry players among its investors and clientele."

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New android trojan horse

asvravi asvravi writes  |  more than 3 years ago

asvravi writes "There has been something of a sting in the tail of the year for lovers of the Android mobile operating system, as researchers (http://blog.mylookout.com/2010/12/geinimi_trojan/) uncovered a new Trojan horse.

The Troj/Geinimi-A malware (also known as "Gemini") has been seen incorporated into repackaged versions of various applications and games. Once the malware is installed on a user’s phone, it has the potential to receive commands from a remote server that allow the owner of that server to control the phone. The affected applications request extensive permissions over and above the set that is requested by their legitimate original versions.

The good news is that it appears not to have made it into the official Android market app store — meaning that you would only have been putting yourself at risk if you installed poisoned software from an unauthorised source."

Link to Original Source
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India SC : Narco test is human rights violation

asvravi asvravi writes  |  more than 4 years ago

asvravi writes "The Indian supreme court banned the use of involuntary Narco tests and Brain mapping techniques as an unjustified intrusion into the mental privacy of an individual and against the evolving norm of international human rights.

In a blow to investigating agencies which routinely use these methods, a three-judge bench of the supreme court held in a 251-page judgment that the involuntary administration of these three investigative tools was in direct conflict with the constitutional right against self-incrimination."

Link to Original Source

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