How to Add Cleaning Instructions to Images with a Canon Rebel T3i
You’ve no doubt noticed that your Canon Rebel T3i displays a Sensor Cleaning message every time you turn off the camera. When you turn on the camera, a little cleaning icon flickers in the lower-right corner of the Shooting Settings display. These alerts tell you that the camera is automatically performing a maintenance step that's designed to remove from the sensor any dust particles that may have made their way into the camera interior.
If you don’t see these alerts, open Setup Menu 2, choose the Sensor Cleaning option, and then press Set. Next, set the Auto Cleaning option to Enable.
The automated sensor cleaning normally is all that’s necessary to keep the sensor dust-free. But if you notice that small spots are appearing consistently on your images, you may need to step in and take action on your own. The best solution, of course, is to take your camera to a good repair shop and have the sensor professionally cleaned.
Until you can have the camera cleaned, however, you can use a feature on Shooting Menu 3 to create a custom dust-removal filter that you can apply in Digital Photo Professional, which is one of the free programs that ships with your camera.
The first step in creating the filter is to record a data file that maps the location of the dust spots on the sensor. To do this, you need a white piece of paper or another white surface and a lens that can achieve a focal length of 55mm or greater. (The kit lens sold with your camera qualifies.) Then take these steps:
Set the lens focal length at 55mm or longer.
Switch the camera to manual focusing.
Set focus at infinity.
Some lenses have a marking that indicates the infinity position. If your lens doesn’t have the marking, hold the camera so that the lens is facing you and then turn the lens focusing ring clockwise until it stops.
Set the camera to one of the advanced exposure modes (P, Tv, Av, M, or A-DEP).
Display Shooting Menu 3 and highlight Dust Delete Data.
Press the Set button.
Press the right cross key to highlight OK and then press Set.
Position the camera so that it’s about 8 to 12 inches from your white card or piece of paper.
The card or paper needs to be large enough to completely fill the viewfinder at this distance.
Press the shutter button all the way to record the Dust Delete Data.
No picture is taken; the camera just records the Dust Delete Data in its internal memory.
If the camera tells you that it couldn’t record the data, the lighting conditions are likely to blame. Make sure that the lighting is even across the entire surface of your white card or paper and that the paper is sufficiently illuminated and then try again.
Press the Set button.
The current date now appears on the initial Dust Delete Data screen.
After you create your Dust Delete Data file, the camera attaches the data to every subsequent image, regardless of whether you shoot in the fully automatic or advanced exposure modes.
To clean a photo, open it in Digital Photo Professional and choose Tools→Start Stamp Tool. Your photo then appears in an editing window; click the Apply Dust Delete Data button to start the automated dust-busting feature. The program’s manual, provided on one of the two CDs that ship with your camera, offers details about this process; look for the Help entry related to using the Copy Stamp tool.