Cleaning your DSLR sensor & viewfinder
The two things that frustrate me the most about DSLRs is caused by the same culprit… dust!! I really hate it when dust gets into my viewfinder & when it gets on the DSLR sensor & leaves those ugly looking dust blobs on my photos.
This is an example of dust on the sensor. You will normally only encounter it when you shoot very small apertures. Contrary to what some people think, dust blobs like this doesn’t happen if you have dust on your lens or your filters. They need to be really big blobs to effect the image like this. Usually the culprit is dust on the camera’s sensor.
Here is the lower left corner section blown up so you can see it better.
Dust in your viewfinder
My advice is, if you can live with it, don’t bother with the dust that is caught inside your viewfinder. It doesn’t affect the photo that you are taking, it only irritates the user that’s all. But if you are fussy like me, I hate it when there is dust on my viewfinder so someone like me would want to get rid of it!
Before I continue, I’d like to make a DISCLAIMER. What I am about to share is something which works for me & by all means I will not be responsible for any of the methods & techniques suggested in this article. I will share my experience in terms of do’s & don’ts but will not accept any liability should you mess up your camera in any way. Many people have a fear of anything done on the focus screens or DSLR sensors but I feel that fear is not necessary if you are patient & careful… and if you have someone like me who have messed up many times before & is able to share with you the pit falls & risks involved lol! Also this guide is based on my experience with the Canon EOS 5DmkII & the Canon EOS 60D.
Equipment, What you will need…
Your camera – Technically this procedure only works on models which allow the focusing screen to be removed or replaced like the 5DmkII or 60D. The focusing screen on a 7D cannot be removed so forget it. Check your camera manual if in doubt.
Clean table with lots of light – Make sure your room ceiling fan or any table top fans are turned off. It’s ok to be in an air-conditioned room but make sure it’s on low. Light can be artificial however I found that natural light near the window is the best.
A dust blower – I recommend a Giottos rocket air blower.
A Canon Eg-A Focusing Screen for your camera – I use a 5DmkII, so I got myself the p/n #CN-SCRN-EGA. Reason for this is because it comes with a little plastic tweezer which I will need to remove the focusing screen. You can use any small plastic tweezer, you just need to be careful that it doesn’t have sharp edges & that it doesn’t scratch.
A Sensor Sweep – I use the ones made by Copper Hill Images. It’s basically a static brush which you charge up by blowing it with your dust blower. It will then attract all tiny particles of dust when you sweep it on a surface you are trying to clean. Although this is optional, I highly recommend this over using only the dust blower because extensive use of the dust blower will cause the surface that you are trying to clean, charge up with static which will attract more dust.
Removing dust from the viewfinder
You’ll need to check three parts from inside the camera to see where the dust is. It can be located on the mirror, the focusing screen or the Superimposed Display. The Superimposed Display is the clear plastic area from behind the focusing screen which has the AF rectangles.
Here is where the mirror is. Very simple here, if you see dust on it, use the dust blower. You can also use the sensor sweep but it’s not really necessary. If cleaning this part doesn’t help, then go to the next part, which is removing & cleaning the focusing screen.
Place the camera on your table with the lens mount facing upward & lift the area I circled in the photo upwards. It will unlatch the focusing screen holder & it should pop downwards at a 45 degree angle.
Grab the little protrusion as shown in the photo using the ‘special tool’ which comes as part of the Eg-A Focusing Screen. You can use a blunt plastic tweezer also but I don’t recommend it.
Here is an image of how the focusing screen “package” comes in.
Here is how the ‘special tool’ looks like holding onto the focusing screen.
Once you latched on to the focusing screen, remove it from the body without touching any part of the focusing screen. This little plastic focusing screen is very sensitive to smudge, finger prints, dust & scratches. DO NOT TOUCH OR DROP IT! You can hold on to it at the edges but make sure your fingers are wash & cleaned before doing so. If you have oily fingers or sweaty palms, beware!
Now it’s time to use the blower on the focusing screen… however DO NOT BLOW DIRECTLY AT IT AT FULL FORCE! The tiny clamps on the special tool will not hold it if you subject it to a hurricane… lol! So please becareful here.
You can also use the sensor sweep to gently sweep both sides of the focusing screen but as mentioned, please be gentle.
Gently reinsert the focusing screen back into it’s holder by means of the special tool & lift the screen holder back into its original position until the latch clicks into position. DO NOT FORCE IT! If the focusing screen is place back correctly, it should be quite effortless to push the screen holder back into position. If it doesn’t, means that you may have positioned the focusing screen incorrectly in the holder. Gently remove it again with the special tool & place it back into position.
Sometimes even after cleaning the mirror & the focusing screen, there is still dust when you look through the viewfinder. If this is the case, then it is likely the dust is on the Superimposed Display I mentioned earlier. Go through the same procedure as before removing the focusing screen, but this time use the rocket air blower on the Superimposed Display. Be careful not to blow too hard as this part of the camera is not entirely sealed so it is possible to blow dust into the underside of the Superimposed Display. I would not recommend to touch the Superimposed Display at all, should the dust cannot be removed then DO NOT CONTINUE! If indeed the dust is bothering you, then it’s time to call on the professionals & get your camera to the Canon service center to clean this part.
Removing dust from the DSLR sensor
What you will need…
A Sensor Sweep – This is all you’ll need 90% of the time.
A dust blower – This will only be used for the Sensor Sweep. Not to blow directly at the sensor. I do not recommend trying to blow the dust off the sensor as you’ll only be blowing the dust around inside the camera & is sometimes really pointless.
A Lenspen SensorKlear – Preferably the version 2 of this product with the articulated tip.
A Lenspen SensorKlear Loupe – This is basically a battery-powered magnifying glass to see the dust on the sensor with. Sold with the Lenspen SensorKlear II, it’s a bargain really.
Cleaning the sensor with the Sensor Sweep
Mount your camera on a tripod with the lens mount facing downward. Charge the sensor sweep with a few bursts of air using your rocket blower. While the camera shutter is in an open positioned from inside the menu option Manually Clean Sensor, using the sensor sweep, perform two gentle sweeps of the sensor forward & backwards with the bristles of the sweep just gently touching the sensor surface. DO NOT PRESS THE BRUSH ON THE SENSOR SURFACE! The brush works on a static principle so just a light touch will pull any dust from the sensor to it.
Turn off the camera & mount a lens… a 50mm will suffice. Set it to f/22 & shoot while on manual focus in an out of focus position on a white surface. Shooting up into the sky will also work. Preview the shot & zoom in to about 100% crop to check if there are any more dust blobs in the photo. If dust still persists, then repeat the procedure in the last paragraph.
Cleaning the sensor with the Lenspen SensorKlear Loupe & SensorKlear II
I only use this method if what I have attempted using the Sensor Sweep fails to remove all dust from the sensor. Failure using the Sensor Sweep usually means that the dust could be sticky or oily & cannot be removed merely by a static brush.
Place the camera on a flat surface with the lens mount facing upward. While the camera shutter is open, place the Lenspen SensorKlear Loupe on top of the lens mount with the power switch turned on. You can look through the eyepiece & inspect the sensor surface. When you find the dust particle, use the SensorKlear II through the access window at the side of the SensorKlear Loupe. It’s easy & quick.
You can view the demonstration from the video below.
Remember that there is nothing to be afraid of when cleaning your sensor or focusing screen on your DSLR. Just use a little bit of common sense, care & patience. If you feel that you are not up to this & you’re not confident, then DON’T! It’s better to be safe than sorry!!