Steve's Digicams Forums

Steve's Digicams Forums (
-   General Discussion (
-   -   Do pixels go bad, or... (

jms Aug 29, 2002 7:44 PM

Do pixels go bad, or...
Do pixels go bad, or do they come from the factory that way? I've read several posts about people who have dead or hot pixels, but am wondering if this is something that develops over time, or just the luck of the draw when you buy the camera.

Jaseball Aug 29, 2002 10:31 PM

Both. I have seen devices arrive bad, develop a fault in a short time, or break later on after a few months. Mainly in LCD screens on laptops.

What is interesting is where the problem in digicams is centered. Is it the CCD, so that the pic comes out with the flaw or on the LCD display? I guess either or both could go and you could find out by taking a quick pic.

whittonj Aug 30, 2002 11:13 AM

Do a search for dead pixel test-- it's a freeware program that lets you test your camera as soon as it comes out of the box. Dead/hot/stuck pixels exist on the ccd and every camera probably has at least one from the factory.

What you want to be really concerned about it something that shows up in the center of the frame and in every-day shots or if you have an abundance of them.

Robert Eastburg Aug 30, 2002 11:38 AM

What does a dead or hot pixel look like? I have a small, round, hardly noticeable dot at the top of my D-60 images.

I haven't learned enough to post a sample yet.

Thanks for any info.


jms Aug 30, 2002 10:18 PM

I'm not sure which is which, but some of the pixels may show up as a green dot instead of the correct color.
The reason I asked this question to begin with is because I just purchased an Olympus C2100UZ. The CCD doesn't appear to have any bad pixels in normal shots, but the EVF has one green pixel. The LCD doesn't show any bad pixels and obviously the pictures I take don't exhibit any bad pixels because the CCD doesn't.
I also did some looking at sample pictures here at Steve's. The review of the Nikon CoolPix 5700 had some samples that showed at least 2 bad (green) pixels in the photographs. That means this fairly high-end camera must have come from the factory that way. And since the bad pixels are on the CCD, they'll always show up in the shots. Not too "cool".:(

whittonj Aug 30, 2002 10:41 PM

I'll post the link as soon as I'm back at my computer at work. The dead pixel test site has an explanation. I'll try to remember...

Go in a dark room, put the lens cap on and shoot a TIFF at 2 or 3 seconds. Open picture in photoshop or some software- white dots that show up are Hot. Zoom in 200% at it will appear as a + of pixels- white, red, blue, green- whatever. These aren't TOO bad if they're not too close- but they will affect night shots.

If the same happens in all your shots whether its completely dark or not- they're stuck. Very bad- they can ruin your shots. You figure in a 6MP image- it probably won't be noticable until you get to 16x20" prints, but...

Take a picture of a white sheet of paper-- look arounf for black pixels-- any black ones- and they're dead.

The problem is they exist in all cameras, all makes and models and you take the chance of getting a camera that is worse if you send it back. If you bought a Canon D60 though I'd expect some serious quality control and wouldn't accept a dslr with bad pixels in every shot.

The lcd having bad pixels isn't a huge deal. Really the LCD is a $25 part of the camera- not the central piece like the ccd.

Robert Eastburg Aug 31, 2002 11:55 PM

Thank you, thank you. It's late now, but I'll try it tomorrow. I have only noticed mine in my skies. There is a small, round dot that is just slightly darker than the surrounding area. It is the same color. That sounds different that what jms is talking about.


All times are GMT -5. The time now is 2:29 PM.