View Full Version : Air Travel, CCD, Dead Pixel prevention


Paul Cronin
December 19th, 2010, 01:28 PM
It has been confirmed to me by a camera tech that you have to be careful of dead pixels from the radiation when flying.

What do most of you do when flying with CCD cameras to protect the sensors?

Allan Black
December 19th, 2010, 02:00 PM
Nothing. The level of radiation needed to cause trouble to cameras would cause serious trouble to you, the crew and all the others in the plane.

Same deal with security xray scanners, be happy don't worry.

Cheers.

Ben Ruffell
December 19th, 2010, 02:01 PM
I usually do a few black balances when I arrive, including the ones where you hold the switch down for ages...

Ben Ruffell (http://www.ruff.co.nz)

Doug Jensen
December 19th, 2010, 09:26 PM
Nothing. The level of radiation needed to cause trouble to cameras would cause serious trouble to you, the crew and all the others in the plane.
Same deal with security xray scanners, be happy don't worry.
Cheers.

Sorry, but you're wrong. It's a known problem and is discussed here by top people in the business:
Pixel Still Stuck (http://www.cinematography.net/edited-pages/PixelStillStuck.htm)

Uli Mors
December 20th, 2010, 01:25 AM
Ever been to a doctor making a Xray picture? Have a look at the plates they use to shield other parts off. Or see the wests they wear to avoid the Xrays impact their own bodies.

Xray and cosmic parts are agressive and small....

Placing the camera in a lead would be a way - but not practical.

The best way is to avoid unnecessary Xrays (usually the security people dont ask you to place the camera in their Xray) and take the camera into the cabin.

ULi

Paul Cronin
December 20th, 2010, 06:49 AM
Thank you Doug,

I knew it was a known problem and was waiting for someone experienced enough to help me out.

Paul Cronin
December 20th, 2010, 07:13 AM
I guess with 10 round trip flights planned in the next four months I will use ground to ship the camera.

There are a few sites that discuss this and of course the skeptics.

It happened to me when I sold my F800 this year. The camera was perfect when sent, Black Balance checked and nice dark screen. When it arrived in CA from RI after being shipped by FedEx air it had 4 white pixels. Sure it could be fixed for $250 and hours with pixel remapping, but why deal with it if you don’t have too. And believe me this is no reason to go CMOS over CCD. CCD is much better for the applications where I use the PMW-500.

Allan Black
December 20th, 2010, 02:19 PM
Guys I stand corrected, in 15yrs on forums first I've ever heard of this.

Uli, my cams are always required to go through airport scanners around the world, so far without trouble.

Cheers.

Paul Cronin
December 20th, 2010, 02:32 PM
Allan,

No worry the fact that you have not had to deal with it is a good thing. I did not know until I had a problem. So I felt it was time to look for solutions and options. And the option I have found are take the risk or ground ship. From what I read even lead will not stop it.

Alister Chapman
December 20th, 2010, 02:43 PM
It's not the X-Ray scanners at the airport that do the damage, it is high energy neutrons from cosmic rays that can lead to bright pixels. It would take something like 200m (600ft) thick concrete or many feet of lead to have any noticeable protective effect. Some of these particles can pass right the way through the earth. So it's not practical to try to shield the sensor. The potential for damage is worst on north polar routes as the earths magnetic field concentrates cosmic rays in the northern polar regions. Transatlantic flights and flights between Europe and Japan use very northerly routes and can be amongst the most likely to incur damage. In this case a single 12 hour flight is the equivalent of around 100 days at sea level in terms of the potential for pixel damage.

Sony now no longer ship cameras or sensors using polar flights. I've experienced hot pixels after transatlantic flights on many occasions, but have always been able to use the cameras masking functions to eliminate them. The same particles can cause problems with memory chips, but in most cases these are not permanent.

The sensor element of a CMOS chip can also be effected by cosmic rays, but they do tend to be a bit more robust and the way a CMOS sensor is read means that any damage may be less apparent.

Paul Cronin
December 20th, 2010, 03:53 PM
Nice summary Alister of the information explained in Doug’s link and a few other sites I have found on the subject.

The high energy neutrons from cosmic rays can pass right through us. They use CCD to count the high energy neutrons from cosmic rays.

Sareesh Sudhakaran
December 20th, 2010, 09:25 PM
It's funny how airplane electronics, mobile phones, laptops and cameras carried by tourists do not suffer the effects of cosmic rays but CCDs do! If a cosmic ray decides to wreck havoc, there's nothing that man has invented that can prevent that. Even power grids and telecommunications go out when that happens. It could affect you even when you're shooting on location. And, lead isn't going to cut it for cosmic rays.

Never had a problem flying with gear and the chances of electronics (including CCDs or CMOS) getting spoiled due to cosmic rays or radiation are far lower than the chances of the car carrying the camera on ground getting totalled by a freight train, or the camera being struck by lightning.

What can one do? Remove the camera battery and always ensure everything is switched off in transit. Use a case with antistatic material. This won't help stop radiation, but it will prevent the camera and case from creating its own magnetic field. A Metal case also helps in keeping the camera electrically isolated.

Alister Chapman
December 21st, 2010, 12:48 AM
Never had a problem flying with gear and the chances of electronics (including CCDs or CMOS) getting spoiled due to cosmic rays or radiation are far lower than the chances of the car carrying the camera on ground getting totalled by a freight train, or the camera being struck by lightning.

What can one do? Remove the camera battery and always ensure everything is switched off in transit. Use a case with antistatic material. This won't help stop radiation, but it will prevent the camera and case from creating its own magnetic field. A Metal case also helps in keeping the camera electrically isolated.

That's not true. Sensor damage due to cosmic radiation is quite common. I've seen it many times on my own cameras. On the ground you can expect a pixel hit between about once a year and once every 100 days. It's just that the cameras pixel masking, some of which is fully automatic will do it's job and hide the damaged pixels. I chase storms driving 40,000 miles a year and I don't get struck by lightning that frequently or get involved in train or car wrecks.

Removing the battery, a metal case, antistatic bag etc make no difference whatsoever.

Paul Cronin
December 21st, 2010, 05:27 AM
I am with Alister, Sareesh you are not correct in your statement. It happens all the time and is a common problem.

Paul Cronin
December 21st, 2010, 05:29 AM
I know what I am going to do to protect my CCD. Take the risk if I need to and if not ship on the ground.

Paul Cronin
December 21st, 2010, 08:20 AM
Thanks for moving this Chris, I should of had it right the first time sorry.

Sareesh Sudhakaran
December 21st, 2010, 08:52 AM
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?

Jason Sovey
December 22nd, 2010, 12:40 PM
When possible, fly at night. Try to put the Earth between you and the sun.

Alister Chapman
December 23rd, 2010, 03:10 AM
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.

Sareesh Sudhakaran
December 23rd, 2010, 09:27 PM
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).

Alister Chapman
December 26th, 2010, 12:31 PM
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.

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.

Sareesh Sudhakaran
December 26th, 2010, 08:56 PM
...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 -


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!

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!

Alister Chapman
December 27th, 2010, 10:36 AM
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.

Kevin Spahr
December 30th, 2010, 08:42 AM
"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.

Panagiotis Raris
December 30th, 2010, 06:55 PM
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 (http://digitalphotographer.com.ph/forum/showthread.php?t=33772)


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.