The following is my personal experience with the Canon EOS 5D and dust particles that seem to be drawn to the sensor like flies are drawn to road kill.
The problem has been well documented on various forums on the internet and my experience has been that the 5D does seem to collect more dust than the other EOS cameras. Not sure why - Is it a design flaw or simply the result of the much larger (Full Frame) sensor?
After shooting several macro shots, I noticed the dust particles showing up when using f/11 - f/32. These aperture settings make dust particles stand out much more than when your lens is opened up. In fact if you shoot at f/3.5 you will likely not even see these particles on your photos.
Here is what I did to clean the sensor: But first, I need to say that this procedure has not been documented or tested further for effectiveness. It is simply another way to clean a sensor. Seems simple but it also seems to be working for me.
After reading MANY posts on some of the internet forums that deal with sensor cleaning, it struck me that no one had tried to simulate the conditions that the camera was assembled in (clean room). Are people introducing MORE dust/dirt particles when they clean their sensors? I think that possibility is VERY likely. Most people don't have clean rooms in their homes so what do they do? Lay the camera down on the bed, remove the lens and clean their sensor! Well, the bedroom is carpeted.... You think there MIGHT be some loose dust particles flying around??? Not a good place to work.
Now, if the bedroom is not a good place, where IS??? How about that tiny bathroom/powder room??? That's better, no carpet, tiled floors - just a few throw rugs maybe. Ok, do a quick cleanup of that bathroom/powder room and read on...
First take anything that collects dust OUT! This would include toilet seat covers, throw rugs, and that furry thing on the toilet tank! (dust magnets)!!!
Now clean/mop the floor.. Don't go overboard with this, but we're trying to make a clean room here. You can ask your wife to clean it like I did :)
Next thing you need (want), is an air purifier with a HEPA filter. I happen to have a Hamilton beach TRUE AIR model number 04161. You can pick one up here: Allergybegone Alternately check out eBay. Your air purifier does not have to be the same model as mine but I would suggest you get one that uses HEPA filters. They are the best for cleaning air. I don't have a whole lot of confidence in the "Ionic" type purifiers. They just don't move enough air.
So, put that air purifier in your "clean Room" and let it run for ½ hour or so. After that you have a pretty good clean room. Not professional by any means but close enough! The HEPA filter cleans the air GREAT!
Next step: Pick up an air blower of some kind. (DON'T use canned air or the sensor cleaning gurus will KILL you)! Propellants splashing all over the place! Just look it up... (Google). I use Giotto’s "Rocket Air".. Get one on eBay or here: Rocket Air
Now take your camera body (with a FULLY charged battery), your tripod and your air blower into your clean room. Set the tripod up. Fully extend the legs and turn the head so the camera faces DOWN! Why? because dust particles naturally float DOWN (it's called gravity - remember Sir Isaac Newton)? You don't want dust to fall INTO the camera, you want it to fall OUT of the camera. DUH! Ok, once you are all set up, blow it!
Turn the camera on and push the "menu" button. Then use the wheel to scroll down to "Sensor Cleaning" and push the "Set" button. Another window will pop up where you should use the wheel to select "Yes" (I'm explaining this procedure for newbies) then press "Set" again. At that time you should hear a "click" when your mirror flips out of the way for cleaning. Now use the "Rocket Air" to blow up into the camera. As the Canon manual says, don't put the tip of the blower into the camera past the lens mount (you don't need to get too close to the sensor). After squeezing the blower 20-30 times, you are done. Turn the camera off.
See samples of my cleaning below. The photos are of my powder room door. Ignore the dark vertical line, it's the molding around the door. Also, there are other tiny specks but I figured they were small enough to consider insignificant.