Digital SLR Camera Sensor Cleaning
The Truth : Does your sensor need an Arctic Butterfly and VSwab cleaning?
DSLR Camera sensor cleaning, for most of us, has always been something of a mystery. One might often feel it necessary to clean one’s sensor, but on the whole, we are all told it isn’t sensible. A ‘don’t-try-this-at-home’ act, if you will.
Through this article I plan to dispel some myths about sensor cleaning in the hope that you will feel more comfortable about obtaining Visible Dust Arctic Butterfly and swabs and removing sensor dust.
This article may appear lengthy, but I urge you, if you are attempting to remove sensor dust, this guide will help you to avoid some of the disastrous mistakes I have seen photographers make on their own equipment in the past.
If you are not confident or do not posess the correct equipment such as the Visible Dust Arctic Butterfly, the Fluids or the swab size for your camera, I strongly advise passing your camera(s) to a professional sensor cleaning service such as Park Cameras who offer both a cropped frame sensor cleaning service and a more difficult and time consuming full frame sensor cleaning service.
I have been conducting professional sensor cleaning for several years, everything from (the rather impudent) Fuji S2 Pros and EOS 30Ds right the way through to D3xs and 1DS MkIII’s. I don’t think it’s a stretch to say that I’ve cleaned hundreds of sensors over this time. From all this I have drawn one solid conclusion: it is difficult to damage a sensor. Provided you take care and treat the sensor like the delicate instrument of precision that it is, you will find it quite hard to damage it.
Truthfully, this is because sensor cleaning does not involve the sensor itself, but a thin plate of glass in front of the sensor, called the low-pass filter. This can be compared to the filter placed over an SLR lens, in that it not only serves the function of filtration but also a measure of protection, and this is what you work with when cleaning your camera’s sensor. That said, it is still very delicate and you should always take extreme care, as damage to the sensor can render the camera beyond repair, especially if your camera is a few years old.
How to tell if Sensor Cleaning is necessary.
The first and foremost point to address is diagnosis. This may seem strange but it could be considered the most important part of the process. Sensor dust gathers at different rates and I’m sure you’ll know if you have a large quantity of sensor dust..
Sensor dust, however, is not the only substance that appears on sensors. Sand, flecks of mud and hairs or fibers are also commonplace. Each of these substances require a different method to remove them, and it’s often difficult to tell simply through diagnosis which it is.
In order to diagnose whether the sensor requires cleaning your best option is to take a picture of a bright, plain object, e.g. the sky, or a sheet of white paper, at a low aperture. The lower the aperture, the more evident the dirt will become. Choosing which aperture to use for diagnosis depends on the aperture you most commonly shoot with, for example if you normally take shots at high apertures, such as f1.8 or f2.8, then using f8 or f11 will be sufficient to diagnose the state of the sensor. If you often shoot in bright environments at low apertures, such as f7.1 or f11, then f22 is your best bet for diagnosis. The reason for this is that it is possible to over-clean a sensor.
Once you have this test photograph, take it to a computer and zoom in to 100%. To zoom closer into the image than this is unnecessary for the purpose of finding sensor dust and other objects which need removing.
From here, you will be able to see any grey or black areas on the image that shouldn’t appear normally. These are your specks of dirt. If grey, then it is most likely dust, if black, then something a little denser. Hairs will appear as a thin line across the image.
Once you have established you need to carry out a sensor cleaning the next step is to access the sensor.
Note: The DSLR Sensor Loupe.
A useful tool to avoid having to always take test shots while cleaning, is a sensor loupe (7x magnification or greater is recommended). Once you know how to get to the sensor (see part II) When using a loupe, move yourself in and out from the loupe. The dirt will often be more visible when you are looking through the loupe from about 4-6 inches away.
The Sensor Cleaning Process : the swabs and the three techniques of sensor cleaning.
Getting to the DSLR Sensor
To do this, take the lens off the camera, put in a fully charged battery, and access the menu option for sensor cleaning (many modern cameras have an automatic and manual option; manual is what we require here) to lock the mirror up and expose the sensor (Nikons generally have the option “mirror lock-up”. If you are unsure, please refer to your camera’s instruction manual).
Air cleaning a DSLR Sensor
The one tool all photographers should have in their kit is the hurricane blower for air cleaning of your DSLR sensor and chamber. The Hurricane Blower is inexpensive and invaluable for the purposes of cleaning a sensor. Before making any contact with the sensor, use the hurricane blower vigorously.
You do this by pointing the camera toward the ground so any dirt being removed is assisted by gravity. Now point the hurricane blower up into the sensor chamber, but keeping the nozzle at least one inch from the surface of the sensor, and squeezing it roughly. Show the hurricane blower no mercy and you will be showing your sensor affection. Repeatedly squeeze the hurricane blower at least 10 times, more if there’s plenty of dirt on the sensor.
Now you should repeat the diagnosis to see how successful you have been. If dirt has been removed, repeat the clean with the hurricane blower 3, 4 or even 5 times to get as much off as you can.
If you have repeated this step 2 or 3 times and have found little or no success, then you should move on to the next steps techniques of brushing and wet cleaning. If you have removed the worst, there is very little dirt left, or if your sensor is now completely clean, lucky you. You have done the job and can go back to taking pictures. For the rest of us, the next step is cleaning with contact.
Brushing a DSLR sensor with a Visible Dust Arctic Butterfly
There are various sensor cleaning instruments that allow us to contact clean the sensor. Some are more effective at certain things than others but our recommendation for this step is to use a static-charged brush called a Visible Dust Arctic Butterfly.
This is used by charging the brush (see instructions provided with the unit) and sweeping it across the sensor gently and slowly, just using the very tip of the brush to contact the sensor (the tip is where the charge is stored). It is advisable to place the camera on a work surface at this point so you can hold it securely in place whilst cleaning. I should note here also that any grease on the brush will more-than-likely be transferred to the sensor, so resist the temptation to touch the brush, and don’t place it down without putting the cap back on. Several sweeps with the brush should lift off any dirt that hasn’t rooted itself to the sensor.
Once again, after cleaning, take another test shot to see if it’s been effective. If so, repeat, if hardly or not at all, then further cleaning is required. This is when we move to the wet clean.
Wet cleaning an SLR sensor with Vswabs
It is important to note, before reading any further, that wet cleaning should be considered the most extreme measure of sensor cleaning, and as such the most hazardous.
It is not complex, but if you are not confident with contacting the sensor by now, I would suggest passing the camera to a professional sensor cleaning service, such as that provided by Park Cameras. It’s fair to note at this point that they clean many sensors most days and remove some quite surprising marks from some very expensive camera’s sensors.
Sensor Cleaning Fluid and Swabs
There are many swab and liquid combinations out there, and most are quite effective. There are surely many I haven’t tried, but from those I have, the most effective and easiest to use I have come across is the Visible Dust Green swabs and the standard Sensor Clean fluid.
As a combination, I have found this to be very good to use, almost never leaving streaks (a characteristic of some of the poorer quality wet clean systems) and removing almost all types of dirt.
Some types of dirt however, no matter which system you use, will smear the sensor after performing a wet clean. This is to be expected, and is part and parcel of the process (in fact, I have on occasion felt relieved when seeing the dirt smear as it can be the first step in removing a stubborn fleck).
Make sure you have the correct sized swab for your sensor. Full Frame sensors are referred to as 1.0, 1.6 cropped sensors such as canon 50D use 1.6 etc. - this is crucial.
Starting the wet clean
I recommend using the hurricane blower on the tip of the swab to remove any dirt or lint that may be there. Next, place small droplets of your chosen fluid across the tip the swab. 2 or 3 droplets should be more than sufficient to cover the whole tip, no matter which swab size you have.
Be very careful to make sure you do not over-moisten the swab. Too much fluid on the swab can cause fluid to leak into unseen areas of the sensor chamber and cause the camera irrevocable damage.
If accidentally over-moistened, throw the swab away and use another. You may be tempted to touch the tip to check its dampness, but this is ill-advised as grease may once again be placed on the sensor by doing so.
To efficiently swab the sensor, hold the swab like a pen, place it on one side of the sensor and move the swab from one side to the other in a single, continuous, firm and slow motion.
Do not put too much pressure on the swab against the sensor; remember, the glass is very thin. Allow the sensor a moment to dry and repeat this, but starting on the other side this time. Two sweeps should be enough to remove the vast majority of the dirt. If you can see a smear on the sensor, a third pass is sensible, but be sure to turn the swab over so as you move across, the cause of the smear no longer presents an issue.
Check your sensor again.
To check, put your lens back on and take another test shot or just look through your sensor loupe if you have one.
If after the wet clean there is still dirt on the sensor, repeat the process, however this time use a new swab, remembering once again to blow on the tip with the hurricane blower before wetting the swab.
At this point you should hopefully have a clean sensor. It is rare, assuming the above steps have been completed properly, that you will still have enough dirt on the sensor to be considered an issue.
If you can still see dirt on the test shot, I would recommend repeating the hurricane blower and dry contact clean steps, but not the wet clean stage. You should bear in mind that the mirror moving during your test shots can re-introduce dust particles back onto your sensor, most likely loosened during air cleaning. This is normal and only requires to be blown away by the hurricane again.
If you are not finding success I would strongly recommend passing the camera to a professional sensor cleaning servicefor either cropped frame sensor cleaning or full frame sensor cleaning.
I hope that you have found this guide useful, that you have been successful and are now ready to take your camera out again to photograph the world.
Happy sensor cleaning and remember, if anything in this guide is unclear, or you simply wish for further advise, please call Park Cameras’ Contact Centre on 01444 23 70 70, where someone should be available to help.
*This article is meant for information purposes only. Park Cameras takes no responsibility for any damage that may be incurred to a camera during the course of following this guide.