Hot Pixel? at DVinfo.net

James Jackson · January 13th, 2007, 09:46 AM

What does it look like?

Matthew Nayman · January 13th, 2007, 09:59 AM

A hot pixel is a little white or discoloured pixel that can appear and slower shutterspeeds or higher gain settings.

Matthew Wilson · January 13th, 2007, 05:11 PM

Best way to check for one is to simply put the lens cap on and turn the gain all the way up. You will see general random noise, but if there is a stuck pixel, it will usually show up as a much brighter dot. Turn the gain down and you should see it get less bright. Temperature can affect them as well. The warmer the camera is, the more visible they can become. If you suspect one, record some footage with the cap on and double check what you see goes to tape. I've had bad pixels in viewfinders that can sometimes look as if they are in the chip block, but of course those do not show up on tape. But rest easy if you have one in your Canon. I've had to deal with them on several occasions including bad pixels and they were fantastic to deal with. Absolutely no hassle (except of course that you miss your camera for a few days).

Bill Busby · January 13th, 2007, 05:51 PM

Quote:

Originally Posted by Matthew Wilson

I've had to deal with them on several occasions including bad pixels and they were fantastic to deal with. Absolutely no hassle (except of course that you miss your camera for a few days).

Obviously, the only way to truly get rid of a bad pixel is to have the ccd block replaced. Of course then there's a pixel masking technique that's usually in broadcast cameras to "fake" it that is firmware driven & can be done on a user level. Too bad the A1 doesn't have this end user remedy.

Just curious Matthew, when you speak of Canon being easy to deal with regarding a bad pixel issue in the past, was that on a warranty basis (which would be a freebie), or was it out of warranty & if so, did they change the optical block, or did they use the pixel masking process & what was the charge to do either?

Bill

Matthew Wilson · January 13th, 2007, 06:09 PM

Good questions Bill,
They mask the pixels and for free under warranty. Fortunately, I have not had the issue come up with a camera that was out of warranty; however, I did have an occasion where there was something like dust or who knows what on the block of an XL2 that was out of warranty and Canon cleaned it for free.

You are right about the only way to "really" fix the bad pixel is change the block, but I've had several broadcast cameras over the years and have had pixels masked and you could never tell.

Matthew Nayman · January 13th, 2007, 06:21 PM

I would settle for masking, but I am disappointed that Canon is saying I don't have a problem. They said they couldn't see the pixel when reviewing the footage, which makes me suspect of the vision of the tech who reviewed it....

Matthew Wilson · January 13th, 2007, 06:36 PM

Yeah, that sounds strange Matthew. Is that from New Jersey or California? I've only dealt with the California folks and have usually hand carried items into them.

Bill Busby · January 13th, 2007, 06:45 PM

I just realized there's 2 Matthews, now known as MW & MN, heheh.

MW, thanks for the info. I can remember even before this masking technology was available the only way WAS to replace the ccd block, which was & still is expensive.

MN, send Canon another piece of footage, but this time process it beforehand with a brightness filter that can be cropped just over the pixel :) OK, I'm kidding... well kinda sorta. Who knows what kind of monitor they're using & how it's set up. It's obvious it's there. I don't get them either :-\

Bill

Matthew Nayman · January 13th, 2007, 08:12 PM

It's actually Toronto... well, Canon in Missisauga...

Matthew Wilson · January 14th, 2007, 06:44 PM

Matthew,
I just took a look at your latest video showing and I would agree , that looks like a bad pixel. I know from speaking with Canon in California that they just run a software diagnostic on the cameras and it will find and fix any pixels. So, maybe if you can just convince them to do that, it will solve the problem.

Matthew Nayman · January 15th, 2007, 12:33 AM

Sounds good. I'll certainly give it a shot.

Mateus Guerra · January 29th, 2007, 09:25 AM

I just received my A1 and notice bright white pixels in lower shutter speeds. They are fixed, but I´ve noticed that when I turn the camera off and give a break using it, later turning it on those pixels appear in different position. The manual says that it might happens with the camera in apperture priority mode ("artifacts (white dots...)". Maybe Canon feels like it is normal this "white dots". If it´s a malfunction, too bad for me, I live in Brazil and received an e-mail from Canon that says that I cant use the camera warranty here.

Another shutter speed problem that I noticed is when I´m in a low light situation with shutter at 1/3, 1/6, gain 0 / 3 db and the iris about to close (F. 8.0+) and a subitle red vertical "footer" (about 10px high) shows up.

Piotr Wozniacki · January 29th, 2007, 09:27 AM

Hey guys, aren't you taking the white noise, introduced by peaking, for dead pixels?

January 13th, 2007, 09:46 AM	#1
James Jackson Regular Crew Join Date: Nov 2006 Location: Leesburg Florida Posts: 65	Hot Pixel? What does it look like?

January 13th, 2007, 05:11 PM	#3
Matthew Wilson Major Player Join Date: Dec 2004 Location: Los Angeles Posts: 259	Best way to check for one is to simply put the lens cap on and turn the gain all the way up. You will see general random noise, but if there is a stuck pixel, it will usually show up as a much brighter dot. Turn the gain down and you should see it get less bright. Temperature can affect them as well. The warmer the camera is, the more visible they can become. If you suspect one, record some footage with the cap on and double check what you see goes to tape. I've had bad pixels in viewfinders that can sometimes look as if they are in the chip block, but of course those do not show up on tape. But rest easy if you have one in your Canon. I've had to deal with them on several occasions including bad pixels and they were fantastic to deal with. Absolutely no hassle (except of course that you miss your camera for a few days). __________________ MW

January 13th, 2007, 06:09 PM	#5
Matthew Wilson Major Player Join Date: Dec 2004 Location: Los Angeles Posts: 259	Good questions Bill, They mask the pixels and for free under warranty. Fortunately, I have not had the issue come up with a camera that was out of warranty; however, I did have an occasion where there was something like dust or who knows what on the block of an XL2 that was out of warranty and Canon cleaned it for free. You are right about the only way to "really" fix the bad pixel is change the block, but I've had several broadcast cameras over the years and have had pixels masked and you could never tell. __________________ MW

January 13th, 2007, 06:36 PM	#7
Matthew Wilson Major Player Join Date: Dec 2004 Location: Los Angeles Posts: 259	Yeah, that sounds strange Matthew. Is that from New Jersey or California? I've only dealt with the California folks and have usually hand carried items into them. __________________ MW

January 14th, 2007, 06:44 PM	#10
Matthew Wilson Major Player Join Date: Dec 2004 Location: Los Angeles Posts: 259	Matthew, I just took a look at your latest video showing and I would agree , that looks like a bad pixel. I know from speaking with Canon in California that they just run a software diagnostic on the cameras and it will find and fix any pixels. So, maybe if you can just convince them to do that, it will solve the problem. __________________ MW

January 13th, 2007, 09:59 AM	#2
Matthew Nayman Major Player Join Date: Feb 2005 Location: Toronto Posts: 917	A hot pixel is a little white or discoloured pixel that can appear and slower shutterspeeds or higher gain settings.

January 13th, 2007, 06:21 PM	#6
Matthew Nayman Major Player Join Date: Feb 2005 Location: Toronto Posts: 917	I would settle for masking, but I am disappointed that Canon is saying I don't have a problem. They said they couldn't see the pixel when reviewing the footage, which makes me suspect of the vision of the tech who reviewed it....

January 13th, 2007, 06:45 PM	#8
Bill Busby Major Player Join Date: Dec 2006 Location: Los Angeles, CA Posts: 959	I just realized there's 2 Matthews, now known as MW & MN, heheh. MW, thanks for the info. I can remember even before this masking technology was available the only way WAS to replace the ccd block, which was & still is expensive. MN, send Canon another piece of footage, but this time process it beforehand with a brightness filter that can be cropped just over the pixel :) OK, I'm kidding... well kinda sorta. Who knows what kind of monitor they're using & how it's set up. It's obvious it's there. I don't get them either :-\ Bill

January 13th, 2007, 08:12 PM	#9
Matthew Nayman Major Player Join Date: Feb 2005 Location: Toronto Posts: 917	It's actually Toronto... well, Canon in Missisauga...

January 15th, 2007, 12:33 AM	#11
Matthew Nayman Major Player Join Date: Feb 2005 Location: Toronto Posts: 917	Sounds good. I'll certainly give it a shot.

January 29th, 2007, 09:25 AM	#12
Mateus Guerra Tourist Join Date: Jan 2007 Location: BRAZIL Posts: 1	I just received my A1 and notice bright white pixels in lower shutter speeds. They are fixed, but I´ve noticed that when I turn the camera off and give a break using it, later turning it on those pixels appear in different position. The manual says that it might happens with the camera in apperture priority mode ("artifacts (white dots...)". Maybe Canon feels like it is normal this "white dots". If it´s a malfunction, too bad for me, I live in Brazil and received an e-mail from Canon that says that I cant use the camera warranty here. Another shutter speed problem that I noticed is when I´m in a low light situation with shutter at 1/3, 1/6, gain 0 / 3 db and the iris about to close (F. 8.0+) and a subitle red vertical "footer" (about 10px high) shows up.

January 29th, 2007, 09:27 AM	#13
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Hey guys, aren't you taking the white noise, introduced by peaking, for dead pixels?