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Old December 21st, 2010, 09:20 AM   #16
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Thanks for moving this Chris, I should of had it right the first time sorry.
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Old December 21st, 2010, 09:52 AM   #17
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Sensor damage due to cosmic radiation is quite common. I've seen it many times on my own cameras.
How do you know it was the cosmic radiation that caused the damage?
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Old December 22nd, 2010, 01:40 PM   #18
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When possible, fly at night. Try to put the Earth between you and the sun.
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Old December 23rd, 2010, 04:10 AM   #19
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Originally Posted by Sareesh Sudhakaran View Post
How do you know it was the cosmic radiation that caused the damage?
Because it wasn't there before the flight and they popped up during the shoot, it was a military flight so no x-ray scanners. It's a well documented phenomenon. Take a look at the video cameras used on the shuttle and other space craft if you want proof, hot pixels everywhere.

Flying at night and putting the earth between you and the sun makes no difference as the particles are not from the sun but from supernovas and other cosmic events all over the universe.
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Old December 23rd, 2010, 10:27 PM   #20
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I've never had problems with gear, neither have I seen anybody else have issues with electronic gear that can be attributed to cosmic radiation. The question still stands - How do you know, without calibrated scientific equipment, that 'cosmic radiation' is the cause? Yes, cosmic radiation is well-documented, but its effects on electronic equipment are hard to study because the particles are elusive. Also, its effects on humans are of far more relevance. The person who started this post must be more concerned about the safety of his crew than his camera.

The point is not whether there is radiation or not, but what can be done to protect from it, if it were true. Seemingly, there is no protection from it, yet most people are not even aware of the issue. But everyone knows about lightening! (Sorry, couldn't resist).
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Old December 26th, 2010, 01:31 PM   #21
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Originally Posted by Sareesh Sudhakaran View Post
Yes, cosmic radiation is well-documented, but its effects on electronic equipment are hard to study because the particles are elusive. Also, its effects on humans are of far more relevance.
Mankind has always been exposed to cosmic radiation and pilots and aircrews have been flying all over the world for half a century without any significant harm. It's not until you leave the protection of the earths magnetic field that it really becomes a concern. Indeed Apollo astronauts reported seeing flashes of light when their eyes were closed which may have been caused by cosmic rays. But here on earth I wouldn't worry.

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Originally Posted by Sareesh Sudhakaran View Post
The point is not whether there is radiation or not, but what can be done to protect from it, if it were true. Seemingly, there is no protection from it, yet most people are not even aware of the issue. But everyone knows about lightening! (Sorry, couldn't resist).
A few minutes with google will turn up plenty of research and evidence on the damage that heavy cosmic particles do to electronic equipment where basically the particle punches a hole through the insulating layer in semiconductors, thus allowing current to leak in or out. This isn't speculation or hearsay. There is no "if", it happens day in day out.
Most professional camera crews are aware of this. Certainly Canon and Sony include a note about white flecks caused by cosmic radiation in their stills and video camera manuals. As I said, and if you do your research you will find that there is nothing practical that you can do to protect your equipment from these particles. It's been speculated that if you surround electronic equipment with a large amount of liquid Hydrogen you can reduce the damage, but that's just not practical or sensible.

There's nothing you can do about it, so you have few choices:
1) Don't buy a video or electronic stills camera with a CCD.
2) Minimise exposure by never placing equipment on an aircraft, if you must, avoid polar routes.
3) Don't stress about it, get on with your work/life and just accept that one day you might get a hit that can't be masked in camera.

There are software plugins that can mask hot pixels in post as a last resort.
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Old December 26th, 2010, 09:56 PM   #22
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...and if you do your research you will find that there is nothing practical that you can do to protect your equipment from these particles...
I think we're on the same page here...except -

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Don't buy a video or electronic stills camera with a CCD
What about the ICs and small SM transistors? EVERYTHING gets affected, not just the CCDs. Might as well not buy any electronic equipment at all!
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accept that one day you might get a hit that can't be masked in camera
Except that you'll never really know what hit you!

Anyway, I think we agree on the main issue. On a less serious note, I'll still place by bet on lightning!
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Old December 27th, 2010, 11:36 AM   #23
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While almost any semiconductor can receive cosmic ray damage it is normally of little consequence as the amount of leakage is so small that at the voltages, currents and frequencies that most circuits operate it is inconsequential. It can be a problem with memory devices where a charge has to be stored for an extended period where the leakage becomes a problem. Even with most memory devices the damage is only significant for one refresh cycle, unless your talking of long term storage (does put a question mark on solid state memory for long term video).
With a sensor where the accumulated charge can be measured in terms of a handful of electrons it really doesn't take much of a leak to create a significant problem.
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Old December 30th, 2010, 09:42 AM   #24
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From the Sony EX3 Manual Page 141

"White flecks
Although the CMOS image sensors are produced with high-precision technologies, fine white flecks may be generated on the screen in rare cases, caused by cosmic rays, etc.
This is related to the principle of CMOS image sensors and is not a malfunction.

The white flecks especially tend to be seen in the following cases:
when operating at a high environmental temperature
when you have raised the master gain (sensitivity)
when operating in Slow-Shutter mode"

I thought I had remembered reading something about cosmic rays in the manual.

I guess every cosmic ray doesn't do serious damage. I personally don't think that I have seen this in my video, maybe my thick head shields the sensor.
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Old December 30th, 2010, 07:55 PM   #25
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seriously this has been debated and beaten to death. yes cosmic rays kill pixels, no its not a big deal. cosmic rays kill pixels while your camera is on the ground too; yes polar regions and high altitude will potentially lead to more ruined pixels, but out of MILLIONS, 20-30 is nothing.

ive flown a LOT, and drag the same Nikon D50 (CCD) and D300 (CMOS) and still have a D2Hs (LBCAST) i drug everywhere too; flown many many MANY times, and all of them have roughly the same number of stuck/dead pixels. UNLIKE most camcorders and Canon DSLR's, with Nikons you CANNOT remap the sensor, so you are stuck with dead pixels.

its NOT that big of a deal; heck even cosmonauts take DSLR's up (and out) in space and do not fret over pixel losses.

Russian Cosmonaut shooting Earth with Nikon D3/D3x - Digital Photographer Philippines


Yes a CMOS cam, but still lose pixels. I also have a D300s and D3X, for their age the CMOS cameras have lost more pixels vs the ancient circa 2005/2004 D50. Xrays do nothing to them in my experience (airport had insisted on scanning my D300 3 or 4 times because it looked 'suspicious with no lens, which was RIGHT NEXT TO IT IN THE DAMN BAG).

bottom line, go out and shoot; even astronauts admit the cosmic rays are not a huge concern.
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