Do you have a stuck, dead or hot pixel in your picture from your Canon? Of course you have. All sensors have defective pixels.
Different types of defect pixels
What are dead, stuck and hot pixels? Well, a dead pixel is a pixel that doesn´t receive any power. It will look darker than the pixels around it. Stuck pixels always receive power and will look like a bright pixel. Hot pixels are visible at high ISO, long exposures or if the sensor is warm.
Methods to remove defective pixels
Long exposure noise reduction
Easy but slow. This feature is available from the menu in your camera. It removes defective pixels in raw and in jpg. You can choose between off, on and auto. When the camera uses Long exposure noise reduction the camera will take a second frame, called dark frame. The shutter speed of the second frame will be the same as for the first frame which means that if you take 1 minute exposure the second frame will also take 1 minute and your camera will be locked during that time.
In camera sensor mapping
The inofficial way to remove hot pixels is to do a manual sensor cleaning. If it works for you it will remove defective pixels in raw, jpg and in video.
Keep the lens cap on the lens and cover the viewfinder. In the menu, start Clean manually and wait for one minute until you turn off the camera. Repeat two or three times if first time doesn’t work.
Easy and fast. It removes defective pixels in raw. Raw converters like darktable and RawTherapee have a one click module that removes all defective pixels in one strike. Lightroom does it automatically but you can’t increase or decrease the strengh of it.