Noticing a dead pixel in my video. Camera, or Lens? at DVinfo.net

Cole Seidl · January 21st, 2011, 12:49 PM

Hi.
I recently completed a short film. I shot with the T2i, and Canon 50mm 1.8.

When the screen is dark enough, I'm noticing a very small, purple, dead pixel. I'm hoping this is a lens issue, as the lens is much cheaper than the camera.

Anyone have an idea what this is, how to repair it, or why this may have happened. I've had the camera and lens just about 6 months, but neither have been used heavily.

Thanks in advance.

Matt Thomas · January 21st, 2011, 05:16 PM

Is it on the footage?

I've got a dead pixel on my LCD screen but that doesn't show up on the footage obviously.

Cole Seidl · January 21st, 2011, 11:13 PM

Yeah, Mine's on the footage. Uploaded to vimeo, on several different computers.. anywhere.

John Wiley · January 23rd, 2011, 06:29 AM

Well it's hard for us to diagnose the problem without seeing any images of it, but dead pixels on DSLR's are not altogether uncommon.

A simple way to test if it is the camera of the lens is to change lenses. If you don't have any other lenses, then I'm sure you can find a friend who'll lend you one to test out.

It doesn't sound like a lens issue because dust/scratches on the lens would not be purple (even if it is purple dust, because it will be backlit the whole time) and it would change sharpness and appearance as you change aperture or adjust focus.

Is the camera still under warranty?

Keith Forman · January 23rd, 2011, 10:27 AM

I thought I had a dead pixel when I first got my 550. It turned out to be a dust particle that couldn't be cleaned with the built-in sensor cleaner. I just lifted the mirror and blew it out.

Khoi Pham · January 23rd, 2011, 11:59 AM

I can't remember if the T2i has manual cleaning or not, if it does, follow the instructions on the manual cleaning and it should fix it for you.

Greg Fiske · January 24th, 2011, 10:44 AM

If it is a dead pixel, go to manual cleaning, put the lens cap on and let it reset for a minute. You can also send it into Canon and they have tools to reset the sensor. I use cc wireremoval in after effects to get rid of the dead pixel.

Cole Seidl · January 24th, 2011, 08:09 PM

I took some video with the lens cap on, as it's more noticeable the darker the screen is. Here is the screen shot.

To my horror, I discovered not only the original culprit, but also many many others... not as luminous, some more purples and a few faded reds.

I tried the "clean now" setting. It said it was cleaning the sensor, then took me back to the menu. I'm having card issues now... I will inspect the footage as soon as possible.

Thane Silliker · January 24th, 2011, 08:13 PM

Looks like you didn't post the screenshot. Been a long day? :)

Dylan Morgan · January 24th, 2011, 08:19 PM

Correct me if I'm wrong, but isn't that just noise that you're seeing in that picture?. Canon 7D ISO versus noise test images Marvelsfilm’s Blog

Cole Seidl · January 24th, 2011, 08:47 PM

Well, I'd feel mighty foolish if that were the case. But I don't believe it is. There is some noise in the image as well, but I am concerned about the small bright purple square in the bottom of the frame, near the center but slightly to the left. I called Canon with the issue, they're recommending that I ship to them for repair.

Greg Fiske · January 25th, 2011, 10:05 AM

I think you ran the auto cleaning. Look in the menu and you should see "manual sensor cleaning", third option down. The camera will not send you back to the menu. You will have to do a hard reboot.

Cole Seidl · January 26th, 2011, 03:29 PM

Ah, that is what I did indeed. Thanks for the clarification!

Paul Cook · February 11th, 2011, 06:55 AM

I just noticed what appeared to be a white dead pixel in some footage I shot using a few different lenses. I did the manual sensor clean from the menu and it seems to have gotten rid of it. I just assumed the sensor cleaned itself after every shut down but perhaps this is a more robust / aggressive clean?

Just in case anyone else finds themselves in panicville :-)

James Binder · February 28th, 2011, 12:28 PM

Cole --

I had the same thing (dead/red pixel) -- in almost the exact same spot. I returned the camera to the shop I from which I bought it (within the store's return time policy) and received a new camera. All is well with the new one.

Return it if you can!

January 21st, 2011, 12:49 PM	#1
Cole Seidl Regular Crew Join Date: Dec 2009 Location: Minneapolis, MN Posts: 126	Noticing a dead pixel in my video. Camera, or Lens? Hi. I recently completed a short film. I shot with the T2i, and Canon 50mm 1.8. When the screen is dark enough, I'm noticing a very small, purple, dead pixel. I'm hoping this is a lens issue, as the lens is much cheaper than the camera. Anyone have an idea what this is, how to repair it, or why this may have happened. I've had the camera and lens just about 6 months, but neither have been used heavily. Thanks in advance.

January 23rd, 2011, 10:27 AM	#5
Keith Forman Regular Crew Join Date: Mar 2008 Location: Williamstown Mass Posts: 192	I thought I had a dead pixel when I first got my 550. It turned out to be a dust particle that couldn't be cleaned with the built-in sensor cleaner. I just lifted the mirror and blew it out. __________________ http://www.vimeo.com/keithforman/videos http://www.keithforman.com

January 23rd, 2011, 11:59 AM	#6
Khoi Pham Major Player Join Date: Nov 2004 Location: Dallas Posts: 747	I can't remember if the T2i has manual cleaning or not, if it does, follow the instructions on the manual cleaning and it should fix it for you. __________________ Khoi Pham www.proeditproductions.com

January 24th, 2011, 08:09 PM	#8
Cole Seidl Regular Crew Join Date: Dec 2009 Location: Minneapolis, MN Posts: 126	I took some video with the lens cap on, as it's more noticeable the darker the screen is. Here is the screen shot. To my horror, I discovered not only the original culprit, but also many many others... not as luminous, some more purples and a few faded reds. I tried the "clean now" setting. It said it was cleaning the sensor, then took me back to the menu. I'm having card issues now... I will inspect the footage as soon as possible. Attached Thumbnails

January 24th, 2011, 08:13 PM	#9
Thane Silliker Regular Crew Join Date: Sep 2009 Location: London Ontario Posts: 94	Looks like you didn't post the screenshot. Been a long day? :) __________________ Regards, Thane Silliker, London, Ontario

January 21st, 2011, 05:16 PM	#2
Matt Thomas Major Player Join Date: Jun 2010 Location: UK Posts: 232	Is it on the footage? I've got a dead pixel on my LCD screen but that doesn't show up on the footage obviously.

January 21st, 2011, 11:13 PM	#3
Cole Seidl Regular Crew Join Date: Dec 2009 Location: Minneapolis, MN Posts: 126	Yeah, Mine's on the footage. Uploaded to vimeo, on several different computers.. anywhere.

January 23rd, 2011, 06:29 AM	#4
John Wiley Trustee Join Date: Oct 2008 Location: Byron Bay, Australia Posts: 1,155	Well it's hard for us to diagnose the problem without seeing any images of it, but dead pixels on DSLR's are not altogether uncommon. A simple way to test if it is the camera of the lens is to change lenses. If you don't have any other lenses, then I'm sure you can find a friend who'll lend you one to test out. It doesn't sound like a lens issue because dust/scratches on the lens would not be purple (even if it is purple dust, because it will be backlit the whole time) and it would change sharpness and appearance as you change aperture or adjust focus. Is the camera still under warranty?

January 24th, 2011, 10:44 AM	#7
Greg Fiske Major Player Join Date: Nov 2010 Location: Santa Ana, CA Posts: 499	If it is a dead pixel, go to manual cleaning, put the lens cap on and let it reset for a minute. You can also send it into Canon and they have tools to reset the sensor. I use cc wireremoval in after effects to get rid of the dead pixel.

January 24th, 2011, 08:19 PM	#10
Dylan Morgan Regular Crew Join Date: Feb 2009 Location: Portland OR Posts: 70	Correct me if I'm wrong, but isn't that just noise that you're seeing in that picture?. Canon 7D ISO versus noise test images Marvelsfilm’s Blog

January 24th, 2011, 08:47 PM	#11
Cole Seidl Regular Crew Join Date: Dec 2009 Location: Minneapolis, MN Posts: 126	Well, I'd feel mighty foolish if that were the case. But I don't believe it is. There is some noise in the image as well, but I am concerned about the small bright purple square in the bottom of the frame, near the center but slightly to the left. I called Canon with the issue, they're recommending that I ship to them for repair.

January 25th, 2011, 10:05 AM	#12
Greg Fiske Major Player Join Date: Nov 2010 Location: Santa Ana, CA Posts: 499	I think you ran the auto cleaning. Look in the menu and you should see "manual sensor cleaning", third option down. The camera will not send you back to the menu. You will have to do a hard reboot.

January 26th, 2011, 03:29 PM	#13
Cole Seidl Regular Crew Join Date: Dec 2009 Location: Minneapolis, MN Posts: 126	Ah, that is what I did indeed. Thanks for the clarification!

February 11th, 2011, 06:55 AM	#14
Paul Cook Regular Crew Join Date: Nov 2007 Location: Sydney, Australia Posts: 174	I just noticed what appeared to be a white dead pixel in some footage I shot using a few different lenses. I did the manual sensor clean from the menu and it seems to have gotten rid of it. I just assumed the sensor cleaned itself after every shut down but perhaps this is a more robust / aggressive clean? Just in case anyone else finds themselves in panicville :-)

February 28th, 2011, 12:28 PM	#15
James Binder Major Player Join Date: Jan 2005 Location: NY, NYC Posts: 367	Re: Noticing a dead pixel in my video. Camera, or Lens? Cole -- I had the same thing (dead/red pixel) -- in almost the exact same spot. I returned the camera to the shop I from which I bought it (within the store's return time policy) and received a new camera. All is well with the new one. Return it if you can!