I have a EOS 5D MK2. Recently I have been noticing that there are blue, red and white dots on my pictures taken. The dots are represented all over the image regardless of ISO-speed.
Can you esperts have a look at these samples, please?
The RAW-image is at ISO-400. It actually looks worse in this ISO-400 image.
The shop where I bought it says that this isnt covered by te warranty. the camera is about 8 months old now.
Those appear to be "hot pxels".
If they appear in exactly the same color and location every time, they are indeed and you should try this...
1. Take off the lens, put on a body cap.
2. Set up the camera for manual sensor cleaning, BUT DON'T REMOVE THE BODY CAP AND DO ANY CLEANING.
3. Start the manual cleaning process on the camera and allow it sit in the cleaning mode for one minute. Then shut off camera.
4. Turn on the camera, let it cycle through the automatic sensor cleaning.
Remove the body cap, reinstall lens and test by taking a higher ISO shot in low light. You might deliberately underexpose and shoot a dark/black object to be able to better see if there are any remaining hot pixels. Don't mistake image noise for hot pixels... they are two different things.
If the above doesn't do the job, repeat steps 1, 2 and 3, then also do a "reboot" or hard reset of the camera...
4. Remove all batteries, 5D series has two: the main LP-E6 and a little button battery in a drawer by the rubber covered sockets (you need a miniature Phillips screwdriver to remove it)
5. Let the camera sit for one hour with all the batteries out.
6. Re-install batteries and turn on the camera. Automatic sensor cleaning and the hard reset will force the camera's computer to map out the hot/stuck pixels.
Again remove the body cap, reinstall the lens and take a test shot.
It is not uncommon for a camera sensor to have some hot pixels. Over time there can be more get "stuck". They simply need to be "mapped out" occasionally.
Note: the above trick supposedly does not work for video. If shooting video and having this problem, you should probably have the camera serviced. It can be compounded and might be more apparent in Live View, too. The "hot pixels" can get hotter and brighter during continuous usage of the sensor, as with video and Live View. I don't shoot video, so haven't checked this out personally.
Also, if you bought the camera new 8 months ago, it should still be under warranty... But with Canon directly, very possibly not with the retailer who sold it to you. Canon's warranty period on cameras is one year. This assumes you bought through an authorized retailer and not a gray market item, which wouldn't be warranted by Canon.