The Canon’s 1DX self-cleaning sensor unit is actually attached to the low pass filter mounted over the image sensor. It is rigged to vibrate and shake dust off. Typically, dust enters the SLR mirror and sensor chamber when lenses are removed and attached, but a certain amount of dust can be expected from normal wear. Additionally, oil from internal components can become dislodged from internal components and stick to the sensor. This is supposedly rare. I sure hope it is…. However, if for some reason the dust doesn’t shake off, remaining dust spots can be dealt with programmatically until such time as you can get it cleaned. Which will of course means that you have to go without your camera for a few days.
When the self-cleaning sensor is enabled, it will engage every time you turn the camera off, or turn it on. I got to thinking that I really only needed it to work every now and then, so I disabled it. Then I went down the rabbit hole. I began to wonder why the feature would be there if it wasn’t useful. Naturally, I then wanted to turn it back on, but I had forgotten how to do it. As I do with all things I think I will forget, I decided to make this little video here that will remind me how to do it.
After watching this video, you may now find yourself wondering about my earlier statement, “remaining dust spots can be dealt with programatically until such time as you can get it cleaned.” I haven’t tried this out yet, but apparently you can, using a single, white card or placard or anything pure white, take a photo and then use the dust in the photo to automatically auto-correct the dust in post. This process is called “Auto Append Dust Delete Data.” Well, a better title would have been “Auto Append Dust Data” because you can’t really delete dust 😉
To do this, (and this is something you may want to do before every important shoot)(I know! All you need is more crap to do, right?) mount the camera to a tripod, make some nice uniform lighting (hey, use spot metering on the camera to check!) on a big card of white paper. Set the tripod mounted camera about 1 foot (30 cm) away from the card. Then:
- go into manual mode.
- use a 50mm or longer lens
- focus to infinity and beyond
- Shoo Buzz Lightyear out of your picture
- Depress the Menu button
- Then, under the third context menu under the camera icon, select “Dust Delete Data” and hit (SET)
- This will touch off a sensor cleaning.
- Now, you need to take a picture. Press the shutter button. the picture is not saved, but the information is collected at f/22.
Once this information has been collected, it will be appended as metadata to all RAW and JPG files. Digital Photo Professional can make use of this data to remove dust. And don’t worry, according to the manual, the amount of data actually attached to the files is trivial, and you won’t notice a significant increase in size.
My camera is new, so I don’t have any dust to report yet. As soon as it does, though, I will come back and try this out, and I will post a How To on using Digital Photo Professional to leverage the Delete Dust Data. Hopefully this works better than making AF microadjustments to my every faithful 2.8 L 24-70mm lens. To be fair to Canon, I did that completely wrong, but more on that, later.