Making Sense of Sensor* Cleaning – Part 1

Disclaimer: I am recounting only my experience and not endorsing any form of sensor cleaning through this posting. You take full responsibility for any actions you take as a result of reading my ramblings…

One of the great things about using ILC cameras, like my trusty Panasonic micro four-thirds, and also DSLRs, is the ability to swap lenses for different situations; a prime lens for street work and landscapes, or a telephoto for wildlife perhaps. This comes at a price though; namely that there is always a risk in getting the sensitive camera sensor contaminated with dust, fibers, and other extraneous crud when changing lenses.

I have been relatively successful over the last few years due to a pathological obsession with how I change the lens (ALWAYS facing downwards) and also because the GX1 and GX8 have automatic sensor cleaning on startup so generally will shake off any dust themselves. However, as is the norm, all good things must come to an end, or the honeymoon period was over, or some such other relevant idiom applied…

I first noticed an “artifact” as it is called, a few weeks back and assumed it was dust or, hopefully not, a scratch on the lens. This was easily disproved by cleaning the lens and then swapping it with another. The artifact was still there indicating something on the sensor. My initial joy at having not damaged a lens was quickly replaced by trepidation though as this meant the sensor needed cleaning.

Having never had to deal with this before this sent me into a bit of a panic, and started off a trail of research on the web to find out what to do next.  

Next step, a cup of tea and a few quiet (and ultimately frustrating) hours on the laptop. Between google, youtube, discussion boards on dpreview, fineartamerica, and other blogs I learned only one definitive thing, namely:

There is absolutely, definitively, no agreed way to clean a camera sensor “properly”. Period. For every expert that says you should do it one way there is another opining why you should not. The information is almost as useless as arguing the merits of Nikon vs. Canon, or DSLR vs m4/3 format.

There is not even agreement whether this should be done by an individual or a professional. Some (usually camera stores) say to send it to a camera store, others say return it to the manufacturer, others complain that the manufacturers make it worse. Some say it’s easy and others, even professionals, seem scared to do the job.

In fact, the only thing that does seem to garner consensus is the first part of the cleaning process, as outlined here:

1. Confirm that the sensor is contaminated. This is done by taking a shot of a neutral object at the smallest aperture available, with the lens defocused (use manual focus). Most like to say f/22 but the lens I had on only stopped down to f/16 but was still good enough to see.  For a neutral object I used the cloudless sky as it was available that day!
2. Use a hand air blower, such as the Giotto Rocket to clean dust off the camera body and lens. DO NOT use compressed air as it contains propellants that can contaminate the optics
3. Expose the sensor (remove lens and lock up mirror for a DSLR, or simply remove the lens on a mirrorless ILC.)
4. With the sensor facing downwards blow air over the sensor to dislodge particles and let gravity take them away. DO NOT touch the sensor!
5. Re-check your sensor by repeating step 1.
6. If you are lucky then the artifact is gone and congratulations to you on a job well done!

For me though, this was not the case, so over to stage 2 cleaning, as I shall call it, and this is where it gets interesting, and confusing, very quickly.

Several photographers state you should start with a statically charged brush such as the VisibleDust Arctic Butterfly and, if that doesn’t work, move on to dry swabbing and then wet swabbing with a solvent. Others state that dry cleaning is wrong as this could scratch the sensor. Yet others preach that chemicals should not be used but rather your breath or a light steam from holding the camera over a cup of warm water!  Some say use proprietary swabs and cleaners such as Eclipse or VDust, others say use simple lens cleaning fluid, or a highly volatile organic such as methanol and swabs made of Pec Pads. The possibilities go on and on and on, each one with its evangelizing defender expounding how they have “done this for years successfully”.

The only take home message that I could really get is that should be possible to clean the sensor using a variety of methods as long as you are careful and methodical, are scrupulously clean, and do not apply too much pressure to the sensor surface when using some form of lint-free applicator!

So, like everyone else who simply uses their own experiences, I will share mine, to date:

I had begrudgingly purchased a kit from Amazon, specific to my m4/3 sensor size and I was amazed at the cost of four lint-free swabs on sticks and a tiny bottle of solvent. It really it quite staggering how this price is maintained in a free market economy. I guess we photographers are saps for this type of thing!

I followed the sparse pictorial instruction, added solvent to the pad and then attempted to wipe the sensor from left to right, hitting my first snag. Although the kit was labelled as being specifically for micro four third sensors the swab was too wide! So, with solvent rapidly evaporating I do the only thing I could do and wipe the sensor from top from top to bottom. Using my handy illuminated head magnifier (see, I knew this would be handy one day!) I could see that the mark had not been removed from the sensor. Drat! So I repeat the process with a new swab with the same result. That means I have used half my swabs and not achieved anything…

… so ends Part 1 of this saga as I consider what else to do. 😦

~Richard

* Of course for the pedants out there we’re not actually cleaning the sensor in reality, but the anti-alias layer that covers it, but what the heck, it’s all the same in the end as it degrades the image