Red stuck pixel on camera?

Messiah Khan

Messiah Khan

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Alasdair Fowler
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Can cameras have stuck pixels on the sensor? Ive noticed that whenever I have dark pictures, a bright red pixel is showing up on all the shots. I looks like you'd get with a stuck subpixel on a LCD screen. I know its not on the monitor, as it stays in the same spot in on the pictures as I move them around the screen. anyone else had a problem like this? Is it fixable, or would it require the camera to be returned?:(
 
Some stuck pixels are considered acceptable. I tested my camera when i got it and found a couple. After the initial concern i looked into it a bit more and single pixels are not usually a problem as it is near impossible to see them in anything other than a test shot.

When you get a couple next to each other they are much more obvious and unacceptable. What camera are we talking about?

The test was a 1 second exposure with the lens cap on and noise cancellation turned off. Zoom in on the image to 100% then pan it around the screen. Any hot pixels should be obvious and you can see if it is individuals or groups.

I normally have long exposure noise cancellation turned on and that removes all the hot spots from long exposures... it just take a while.
 
If it's under guarantee send it back.
There shouldnt be any "hot" pixels.

If not and you can live with it then as RP says ... ho hum
 
Its on a D40x. Im fairly sure theres 1, bu being red, it stands out quite a bit on dark shots. I would consider returning it, but I bought it from Jessops, and I actually bought(and payed) for a D40, but they accidentally gave me a D40x instead. So id rather not return it and end up getting back a worse camera if you see what I mean.
 
I have shed loads on a 5D when I'm doing 100 sec plus exposures but I guess that's normal. I don't think there's zero tolerance from manufacturers for this sort of thing.
 
Thats unlucky milou. I guess im just going to have to live with it and clone it out when needed. Shame though, as its going to annoy me from now on.
 
oldgit said:
If it's under guarantee send it back.
There shouldnt be any "hot" pixels.

If not and you can live with it then as RP says ... ho hum
Click to expand...

I'm not going to search again now but when I first got the camera and checked up on it individual hot pixels are normal but clusters are not. Some makes (Oly?) even have a mapping function to map out the hot pixels.

If you don't go out of your way to look for them you may never see them. Have you tested your camera?

Milou - I don't get any on long exposures as the noise cancelling removes them. Never tried 100 seconds though only 30. Does it have a time limit?
 
Not sure if truth be told. I think the NR takes the same amount of time to work as the exposure. Sometimes I'll doing 400 secs. I think I'll have a play to see if it works in excess of 30 secs.
 
I believe that the 'Nikon Capture' software allows you to 'map' sensor dust, and it then clones out the marks automatically.

Could you possibly use it in the same way, identifying the dead pixels as sensor noise?? I can't think of any reason why you shouldn't.
 
thanks for the suggestion dougdarter. I use Lightroom though, and id rather live with the pixel, than change my workflow. I know on stuck pixels on LCD screens you can sometimes 'massage' or flash them out. Wonder if something similar is possible on sensors?
 
Forget it, just clone it out if you see it on an image.
 
milou said:
Not sure if truth be told. I think the NR takes the same amount of time to work as the exposure. Sometimes I'll doing 400 secs. I think I'll have a play to see if it works in excess of 30 secs.
Click to expand...
noise reduction in canons is done by subtraction process, say you took an exposure of 100secs with NR on, first shutter opens for 100secs on your scene and it shuts - noted by the click-chunk of ther mirror/shutter leaves going down. next it takes a 'blank' with the shutter completely shut but again for 100secs. then it takes the blank and takes away the points that light up from the actual capture...hence noise is reduced.
I've yet to fully experiment with this but be aware you need to have a decently recharged battery to do this as - obviously - its taking twice the number of shots. longer exposures again could be problematical...I think if it shuts down mid-process then you've lost the shot as it writes to the card after the subtraction process.

anyone care to correct me?
 
RobertP said:
I'm not going to search again now but when I first got the camera and checked up on it individual hot pixels are normal but clusters are not. Some makes (Oly?) even have a mapping function to map out the hot pixels.
Click to expand...


Yeah i can map out any bad sensors bits if i have too. not seen anything yet though.
 
My 400D has a white spot in the lower left hand corner, it's not very obvious unless the background is black. It only shows up on Jpeg though, not RAW, I would have though it would be the other way round. :s
 
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