Canon 60D Red Pixels

[moellera]

I have a Canon 60D camera.  I have noticed that when I take longer exposure photos, I have a number of pixels in each image that are red.  There are at least 6 different pixels that consistently only register red.  Is this a warranty item?  How do I get this fixed?

[Skirball]

You can send it in to the service center and they’ll decide if it’s covered or not.  But if it is all they do is remap it to ignore those pixels and use the data from the surrounding pixels.  If it’s only happening on long exposures I suggest just using long exposure noise reduction, it will factor out the hot/stuck pixels – of course, it takes twice as long to take the shot.

[TCampbell]

If it ONLY happens on long exposures then it's probably not a defect.

All sensors generate image "noise" as a result of heat -- typical of long exposures.  You can activate your camera's "Long Exposure Noise Reduction" (this is in C.Fn II: Image and it's #1 in that category).  

This causes the camera to take a 2nd image immediately following your long exposure.  The second image will be taken using the same ISO and exposure time as the first, EXCEPT... the shutter will never open.  The camera is deliberately taking a "dark frame".  Any pixels appear on the dark frame represent noise and will be subtracted from the first frame.

While this works, it is not perfect... some pixels tend to be more consist and so you can get one type of noise which shows up consistently at the same pixels if the camra's sensor temperture was the same and the exposure settings are the same.  HOWEVER... some noise really is just random.

Astronomers take mulitple images and use "stacking" because consistent points of light (no matter how faint) that appear in every frame, probably really are stars (just an example).  But pixels which vary randomly frame frame to frame probably represent noise (the stacking software automatically cleans those out).  Pixels with consistent noise will still appear in every frame (and in the same spot) so "dark frames" and a technique called "dithering" (we _very_ slightly move the scope by just a few pixels) will reveal those pixels making it possible to eliminate them as well.

Incredibly high-end imaging cameras use special chillers to keep the sensor temperature WELL below ambient (often these can have their temperature reduced 40 to 60 degrees C below ambient temps) to keep noise levels down.  But cooling systems are normal for those cameras (and not for DSLRs) because those cameras are primarily designed knowing that it'll be imaging for hours on end and heat would be a real problem.