View Full Version : Filthy sensor !

16-06-2006, 12:02 AM
Digital SLR cameras have a bit of an issue with dust. Because the sensor never moves (like a roll of film does) dust can build up on the sensor when changing lenses, especially in the sort of photography I do.

The dust is more evident at small apertures with a noise-free background (like a sky) especially if the focus is off making everything (but the dust) blurry.

My Nikon never had any real issues with dust on the sensor, its never intruded on the photos so theres no need to clean it even after 2 years track side.
My Canon on the other hand has had less than 6 months and its got progressively worse and worse, some of the recent photos have had to have some photoshop touchup to just get rid of the dust artifacts.

This is what it looks like: (contrast is adjusted to make the dust show up more)


That photo is taken at a SMALL aperture, F9, the smaller the aperture (bigger number) the more the dust is evident.

Cleaing the sensor is a bit of a tricky thing to do, one false move and you can damage it and ruin the camera. Blowing or brushing doesn't do much other than add more dust and make things worse.

This is the gear required to clean the sensor:
Special pads which are wrapped around the swab stick and taped on, a couple of drops of juice (Eclipse) are applied, and the completed swab is ready for 1 pass on the sensor.
Because the sensor on my Canon is quite big it needs 2 passes so I do the top left to right, and the bottom right to left.
The rubber gloves just stop any grease from my hands getting on the swipe and getting onto the sensor.

This is a photo of a white wall AFTER 3 cycles of cleaning, there is still a couple of specs of dust on the left - mainly at the bottom.. but since they are small and at the edges I'll leave it for now and see if they are evident on the action photos - no point cleaning it unless its absolutely needed in my opinion.
(contrast is adjusted to make the dust show up more)


Above photo is at F22 (smallest aperture) and is about 10 second BULB exposure waving the camera around to make the entire image blurry to make the dust show up better. The white lines and dark areas are just the lighting / blur.

Might interest someone :)

16-06-2006, 06:13 AM
cool, you say I wont have to do that when II buy my Nikon D50? What lens did you have on your d50 btw?

16-06-2006, 06:52 AM
Thats me in the picture! :o


16-06-2006, 07:09 AM
My friends D70 needed cleaning not long after he got his camera, not sure why. My D70 has never really needed it, it does have dust on the sensor but until I see it in the photos I take then It's not worth worrying about.

16-06-2006, 08:12 AM
With all that gear it looks like you're about to stick yah hand up a cows bum!

Still, interesting none the less.

16-06-2006, 11:32 AM
jimmy are all your lenses L lenses? These are typically better at avoiding dust. When I change lens I do it in my car when trackside.

Great tutorial though.

Its also worth getting your camera serviced every year.


16-06-2006, 11:40 AM
I only use the 70-200 L and the 50mm prime (for reviews only). The 70-200 stays on the camera almost all the time.
The D70 however, I have changed inches away from racing cars many many times, still ok. :o

16-06-2006, 11:47 AM
which 70-200 is it? I thought that the 2.8L and te 2.8L IS where weather proofed....

it is a major issue and I spend sunday night cleaning everything after race day. Last race day (see other thread) and the dust was hurrendous.

16-06-2006, 03:44 PM
J, whats the chance of you bringing your cleaning stuff to the batley national - I'm sure you can guess what I'm after...............

I have used a brand new eye shadow brush that the wife had to shify a bit of dirt but it's not perfect.

16-06-2006, 05:30 PM
Is that the only time you borrow the wifes eye shadow brush?? ;)

16-06-2006, 09:11 PM
The 70-200 is the IS L lens, fully weather proofed. Not sure if the Canon is more attractive to dust or what, but it certainly has more than my Nikon.
I dont usually clean my cameras much, I dont clean the front glass unless it really is bad, a bit of dust or something doesnt bother me (cant be seen in the photos).

Is your sensor dusty Stu ? I dont mind cleaning it for you if you want ? Either way I can bring it to the next meeting for ya. bit of care and time is all thats needed.

16-06-2006, 09:24 PM
I'm more of a blusher man.

Looking at he sensor you can't see much. I can see some marks on pics where the aperture is small (look like small curly hairs - no I've not been taking that sort of pics), the eye-shadow brush seems to move them about.


To be honest Jimmy I'm interesterd in seeing the ceaning in action. Some of the stuff would be useful to Me & my brother (20D) and a lad at work who has another 350D.

16-06-2006, 09:31 PM
No worries mate, best way to see your dust btw is to stick it into F22 (or whatever) and set it to manual and do like a 10 second exposure (depending on light vary the exposure time, thats for indoors really)

then wave the camera about like a maniac.. youll get a really blurry photo with sharp dust / hairs - all being well.

16-06-2006, 09:51 PM
http://northernracer.com/2.jpgMy short & curly seems to have migrated to the top left-ish.

Looking at it its not that bad, I'll see you at the meeting.

16-06-2006, 10:35 PM
Might be able to blow that off with my blower, but that could stir up other dust so maybe not worth it. The swipe method takes it out not just moves it.

10-07-2007, 07:18 PM


I made a 'swipe' tool out of some thin bendy plastic. It took me a while to hunt about for something that had enough strength to apply some uniform pressure but was bendy enough to make sure it was delicate. I could also cut this to the exact right size for the sensor. I bent it double to make sure there was a nice radius over the end.
The wipes are www.whatman.com (http://www.whatman.com/products/?pageID=7.29.142) and the cleaning fluid is pure isopropanol alcohol. I was VERY careful to just dampen the wipe with cleaning fluid to avoid dirty fluid bleeding up the back of the sensor.

10-07-2007, 08:16 PM
Looking at he sensor you can't see much. I can see some marks on pics where the aperture is small (look like small curly hairs - no I've not been taking that sort of pics), the eye-shadow brush seems to move them about.


Tell you what Stu, you want to get rid of those hairs.....they look like birds!:rolleyes:

10-07-2007, 08:32 PM
That was taken quite a while ago when it was still fairly clean, it was certainly clean compared to how dirty it did get.