Cleaning Your SLR

Sensor Versus Mirror

I’ve written several times on the blog about cameras, sensor dust, and cleaning your SLR.  You can review those here, here, and here (5 Ways to Clean, 5 Times to Clean, and 5 Ways to Avoid Dust).  I’ve also elaborated a bit on the various options for cleaning your SLR from the no-contact to the wet and dry methods, but I’ve never really addressed the fundamentals behind camera dust in question.  So, when someone asked recently on Quora about the Self-Cleaning Mechanisms in SLR’s, I figured a more complete write-up might help.  This was posed on Quora recently, and in the interests of sharing the points I made there to any of the reading audience here, figured it’d be worth inclusion.  So, without further ado – here’s the full skinny on SLR’s and self-cleaning:

The Self-Cleaning Mechanism

Dust Delete

The self-cleaning mechanism of SLR’s has many larger concepts that need to be addressed to fully understand what is happening, but in basic principle, a camera will use the battery to either shake or vibrate the dust off, or, it will negatively charge air particles that will attract the dust off the sensor and let the now airborne dust fall down to the dust trap at the bottom of the sensor.  Having said that, there’s a couple additional points to make in this question that can help:

Sensor Cleaning Versus Mirror Cleaning

Sensor Versus Mirror

The internal self-cleaning addresses the sensor itself, whereas DIY cleaning methods really are addressing the mirror that reflects an image onto the actual sensor.  Unless you want to lock the mirror up (such as on older cameras) and clean the actual sensor, any cleaning efforts you do on newer cameras is really only addressing the mirror.  Because of that, the internal sensor cleaning will address the sensor cleaning adequately, but does not address the mirror in the SLR  (until of course the dust trap fills up and needs to be emptied by an authorized professional from Canon, Nikon, or other third party).  When it comes to cleaning the mirror, you will have to do that yourself.

Is the dust really being removed?

While the self-cleaning function does “remove” dust from the sensor, through either vibration (or shaking), it’s not really removing the dust from the camera.  Here is where the larger question of “where does it go” remains unanswered for the most part, and also where the usefulness of the feature sort of falls flat.  Inside cameras that have this feature, there is a dust trap at the bottom of the sensor that catches dust when it is shaken off the sensor and/or sensor mirror.  Simple laws of physics suggest that eventually this trap will get filled, which means it needs to be emptied, or you need to send a camera in for cleaning.

Preventive Maintenance

While I have personally found that the self-cleaning feature is useful to a degree, the fact that dust is not being removed entirely from the camera detracts from its value, as well as the consideration that difficult or stubborn dust is not removed sort of devalues the benefits in the long term.  Instead, incorporate a system when using your camera to avoid introducing dust in the first place, such as some of those mentioned already, including, but not limited to:

1.  Keeping the camera pointed down when changing lenses
2.  Using a changing bag
3.  Turn the camera off before removing a lens
4.  Change a lens as quickly as you’re able – the longer the face is open the more chance of additional dust being introduced.
5.  Keep your camera clean and try to change lenses in less dusty situations (i.e. not in the middle of a sandstorm)

DIY Mirror Cleaning

There are several methods of dust removal you can use such as the use of a Rocket Blower (also use with the camera pointed down), mirror wipes, lens pens, and other similar products.  These are often categorized as no-contact and contact cleaners.  Within the contact cleaners, there are also sub-categories:  wet and dry cleaners.

No Contact Cleaners
No contact cleaners (blowers) use a puff of air to dislodge dust from the mirror and when used properly, the dust will fall out of the camera entirely. A great product in this category is the Giottos Rocket Blower.

Giottos Rocket Blower

Contact Cleaners – Wet Versus Dry
Dry cleaners generally refer to the brushes like Lens Pens that act like a paintbrush of sorts that sweeps dust off the mirror.  Conversely, the wet cleaners use a pad and a liquid that is swiped across the mirror to swab the dust off with a quick drying agent (usually some form of an alcohol) – the one I’ve used is a combo of Eclipse solution and PecPads.  Both of these often come with increased risk of damaging your camera, so I would only recommend these for those comfortable with the mechanics of cameras in general.  The dry cleaners are less likely to damage, but still carry some risk, so keep these in mind in your cleaning approaches.


I’d also be interested in hearing what others think of the “Self-Cleaning” SLR’s…do you use this feature?  Do you find it useful? Do you clean your own camera, and if So, how often? Feel free to sound off in the comments below!

Friday Frenzy

Just a quick wrap up here for the week as the day is getting late, and I’ve got miles to go before I sleep.  Um…yeah, okay, that came from a poem somewhere but I forget who wrote it or the title, so no credit line on that.

As we all know by now (unless you are in a cave somewhere in the Congo), Canon has released the 5D Mark II and the specs were posted here a few days ago.  Forums and the blogosphere have poked and prodded at just about everything they can until the camera itself comes to stores in October.  So, for the time being we will likely see just more pontificating.  As for the content here at CB, I am probably gonna draw back a little and let others wax on about it.

In more current events, Adobe released the Camera Raw update for all your product needs.  It’s now at version 4.5, and is available for Mac and Windows download free here:  Camera Raw 4.5

What the Duck had a great week from the comedic standpoint, and I really can’t pick a favorite, so just go there and read through them all!  Great stuff!

Nominations are now open for the Podcast Awards for 2008.  They close at the end of the month, so be sure to stop in and let them know who you think is deserving of the awards for this year.  I’ve also got a link to them on the sidebar with a suggestion for CB (hint hint:  Education).  There’s 22 different categories so be sure you’ve got the URL’s for all your favorites handy to plug in the appropriate content areas.  Others that I would recommend for nominations include:

The list goes on and on, but there’s only one tech category and most of the blogs I visit fit that area.  Although there is a People’s Choice category too.  As for CB, I’ll stick with the educational theme.  So, if you think I’ve helped with education in photography and photoshop at all, then add a kudo in there.  Who knows – maybe I’ll actually make the top ten in that category! 🙂 (I doubt it though…but it never hurts to self promote, so there it is!)

Also, I’ve got a new poll up on the sidebar.  After posting the features about the 5D Mark II, I thought it might be interesting to see what features people would like to see in their camera gear.  You can pick any three, so let’s Rock the Vote (so to speak), and get those opinions in.  I wanna hear from YOU!

Finally, I thought I’d share a shot I did kind of by accident.  I was trying to do some night photography with HDR in mind.  Nothing came out all that well so I just started trying all sorts of things.  Came up with this:

3 of Me
3 of Me

Do you like it?  Too much?  Not enough?  Is it too processed?  I’m kind of biased, so rather than reveal my own thoughts on this, I’ll leave it to the readership to decide if this works at all.  Please share your thoughts in the comments!

Okay,  so much for a quickie!  I’ll just leave it at that, and wish you all an excellent weekend filled with productive and creative results.  Happy Shooting!