Experience with sensor dust

borrel

borrel

Børre Ludvigsen
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Experience with sensor dust

After owning a few digital cameras with interchangeable lenses it's
time to share some experience of sensor dust. I own or have owned the
first Canon D30, then a D60, the 5D, Epson R-D1 and now the Leica
M8. It was only with the R-D1 and the M8 that sensor dust really
became a severe problem. Not that it wasn't present in the dSLRs, they
just seem to be so much easier to keep clean. Most of the time a
couple of blows with a pneumatic duster and it's gone. It's with the
rangefinders that the real problems arose. Both cameras came with dust
as a feature. Or at least they generated dust very quickly after the
first few shots. The R-D1 was the absolute worst. Suddenly there would
be dust, large and small all over the sensor. With a magnifying glass
it could be seen clearly spread all over the sensor. The M8 hasn't
been very much better.

It would appear that the all-metal construction of the range-finder
cameras create greater problems with differences in static charge than
the SLR's which have more plastic parts. I also suspect that there is
a difference in the amount and type of lubricants used resulting in
fewer lubricant coated particles flying about in the chamber when the
shutter is released on a dSLR. The mirror may also contribute by
catching particles falling out of the lens assembly.

I have tried everything. Read up on just about every web page I could
find. Taking out the memory chip to prevent static charging of the
sensor, blowing, vacuum, pointing the lens mount down when changing
lenses, etc., etc.. I've also finally found out how to clean the
sensor properly and seem to understand where most of the dust comes
from and what makes it stick so obstinately. There's a whole
combination of factors that generates dust and some points that make
digital dust problems quite different from analog film dust. With
film, there is only the little dust that might accumulate on one frame
before it is moved away from the film gate. There is very little or no
static charge to attract it too. The sensor that remains permanently
in place is a very different proposition.

Sources of sensor "dust":

- External, air-borne pollen, fiber and other floating
particles. These are most often attracted by a sensor or shutter
chamber which is somehow charged with static electricity of
opposite polarity.

- Internal particles from the shutter mechanism and lens
assembly. The most obstinate and potentially damaging, these are
the particles that appear to come out of "nowhere" in a new
camera. Often coated with some form of lubricant, they stick to the
sensor filter and cannot be removed by blowing or brushing.

Removing "dust":

- Forced air, either in the form of a blower or vacuum will remove
dry, air-borne particles. Removing static charge from the camera
and sensor by turning off the sensor (either using the camera's
"sensor cleaning" option or taking out the memory card) and
grounding the camera and hands will help. First blow into the
shutter chamber with shutter closed to remove dust outside the
shutter curtain, then trip the shutter and blow clean the
sensor. Keep in mind however, that both blowing and vacuum will
force air from the external environment into the camera replacing
the moved air and bringing with it potentially dust-laden air. Try
to hold the front of the camera pointing down when blowing so that
air-borne particles don't fall into the lens opening.

DO NOT blow into the camera with your breath. Moisture and or
spittle particles will only make matters worse either soiling the
sensor or helping dust stick to it.

DO NOT use compressed air cannisters. The wrong type or holding
them in the wrong position may force lubricants or water onto the
sensor. When compressed air is release from a container the air
temperature drops dramatically sometimes to the point of freezing
carrying ice particles with it that melt on hitting warm surfaces.

Keep in mind that excessive blowing will force dust into cracks and
crevices from which it will be almost impossible to remove, but
where it will also be waiting for a jolt or vibration to float onto
the sensor.

- Brushing the sensor with a CLEAN brush. There are several types of
special brush available for the purpose, but a soft, CLEAN sable
hair artist's brush will also do. The idea is to shift the dust off
the sensor and have it stick to the hairs of the brush. Clean the
brush between strokes by flicking it lightly with something CLEAN
or rotating it rapidly. (Some brushes have a built-in motor for the
purpose, but an artist's brush can be rotated between the palms of
the hands.) The key words are DRY and CLEAN. You don't want to
smear oil coated tiny metal particles from the shutter or lens
assemblies along the glass surface of the sensor filter. Nor do you
want to deposit natural acids and oils from your fingers on the
sensor glass.

- Dry swabs. These basically act just like a brush, attracting dust
which hopefully sticks to the swab which is then discarded. All
things considered, chances are the dust will just be moved around
on the filter to pile up at or just outside the edges where it will
be waiting for static and vibrations to redistribute it. Not
recommended.

- Wet swabs. Use CLEAN swab material and CLEAN industrial alcohol
for cleaning optics. Use no more liquid than the swab will retain
when pressed against the filter glass covering the sensor. There
are various suppliers of these materials including those who have
been in the business of supplying cleaning materials for fine
optics before imaging sensors came along, so it doesn't have to
cost enormous amounts. The purpose made equipment is however,
easier to use. The whole point of the exercise is like washing the
floor with soap and water. A couple of drops of liquid on the swab
and stroke the sensor with moderate pressure. The process will
remove all loose dust and most greasy particles including grease
smudges. The dried liquid may or may not itself leave faint
smudges, but using swabs that match the sensor size helps.

Tips:

- Keep the shutter chamber clean. Notice how dust collects around the
controls on the top of your camera even with daily use. The same
dust is itching to get into the shutter chamber. Some of it will
surely get in there by itself unless you have a dust sealed camera
like the Canon 1D's. The rest will try to get in when you change
lenses and average range-finder user probably changes more
often. Try to ground yourself and hold the camera pointing down when
changing lenses. Clean the shutter chamber from time to time with a
simple air-blowing brush. Blow clean the back of your lenses
occasionally keeping in mind not to pick up grease if using a
brush blower.

- The filter covering the image sensor is a pretty robust piece of
glass. Don't be afraid to clean it when necessary. Providing you
are using CLEAN materials meant for cleaning optical surfaces,
applying moderate pressure and cleaning repeatedly will remove the
more obstinate particles.

- Do your sensor cleaning in a reasonably dust free environment. Use
good light and a strong magnifying lens or glasses that focus on
the surface of the sensor so that you actually see the dust you're
trying to remove. It really helps to see what you're doing. (Watch
out for dandruff!)

- Control your results by taking a picture of a uniformly light
surface with the smallest aperture. Then review the image on the
camera LCD at increasing levels of magnification scanning the image
row by row. Make a note of any remaining dust and locate it
visually on the sensor for re-cleaning.

- Thoroughly clean all external surfaces of the camera with a good
microfibre dust cloth. Clean the shutter chamber - with shutter
closed- and lens rear assemblies with air and brushes. (Separate
brush for each part to avoid transporting grease.) Then clean the
sensor with wet swabs until no dust is visible in
pictures. Thereafter the occasional blow or brushing should be
sufficient until the shutter decides to spit on the sensor or a
rear helical on a lens feels its time to drop a nice, fat glob of
grease with a particle of brass milling in it when you put your
camera down lens up!

Finally - don't be afraid to clean the sensor in your (interchangeable
lens) camera. The designer knew it would attract dust and designed
it to be cleaned. Use the right cleaning material and don't blame me
if you do anything wrong.

- Børre Ludvigsen (August 2007)
 
Great information. My observations are that my M8 has the least amount of dust problems. My Nikon fair next to the M8 and my Canons are the WORST!

I have had very little problems with dust with the M8 and air has taken care of the little I did have!
 
Does the absence of an anti-aliasing filter on the M8 make the sensor more sensitive to scratching when being cleaned?
 
Tuolumne said:
Does the absence of an anti-aliasing filter on the M8 make the sensor more sensitive to scratching when being cleaned?
Click to expand...

I shouldn't think it matters. The designers must have known that the sensor would need cleaning and chosen material accordingly.

- Børre
 
Bought my M8 last November and haven't cleaned it yet. (Yes, it flew to Solms last December for the "fix" too.)

I'll clean the sensor sometime soon. Thanks for taking the time to post this very helpful guide. I'll print this out and keep it with the M8's instruction book.

-g
 
I work in a professional Camera Rental Dept. The method we use for identifying whther or not we need to clean a sensor is as follows.

-Set up an evenly lit white piece of clean fresh printer paper/photo paper.
-Use a normal focal length lens and open up to around F22 or smaller.
-Make an exposure not worrying about focus.
-Upload image into photoshop.
-Use the 'Equalize' function to balance the image.

You will immediately be able to see where on your sensor has dust. Grey blobs appear where their is dust.

-Next we use a clean compressed air system (you can use a clean air bulb, etc.)
-Repeat test shot to determine if dust is mearly surface or requires a cleaning swab.

If we can't remove the dust we send our cameras either back to the manufacturer for cleaning or to a few professional repair stores.

I hope this helps anyone wanting to know how to discover if their sensors are dirty to be able to pin point and then tell how clean you have it.

Remember you will probably be able to see much more dirt than will ACTUALLY affect your image. The photos you will be taking will hopefully be a bit more exciting than a flat white surface! Tonal and Contrast changes will hide most dirt even from someone looking for it. So a bit of dirt can sometimes be acceptible. It will have to be since there aren't readily availible sensor cleaning devices except in a few of the newest models. This test will work with all interchangable lens digitcal cameras, slr's and rf's.

Thanks Borrel for your detailed sensor cleaning list! Very helpful.
 
Last edited:
My first experience with sensor dust occurred last week after a trip to a Northern California beach. This is after having the camera for two years.

Now I have to deal with cleaning it.
 
I've had Fuji S1, Canon 1D (briefly), D30, D60, now 20D, RD-1 and now M8. Contrary to Greg's experience, I found the Fuji, Canon 1D (original, 4MP) and RD-1 worse by far than the 1.6x Canon's, which to tell the truth I never had to clean. That would correspond to what I've read that CMOS sensors attract less static dust than CCD's (the original 1D is a CCD). Too soon to tell about the M8, but it's a CCD. Also, when you change lenses on an SLR the mirror is up front and glass tends to attract dust and hold it, whereas with the rangefinder any dust entering the chamber lands right on the shutter blades.
 
Re: Sensor damage and hesitation. Here is a bit of what Leica say about sensor cleaning:

"Another good idea is to make a habit out of cleaning the camera interior using a lens blower, as provided for this purpose by camera stores; alternatively you can use an enema syringe, which will be available at the local pharmacy. Dust particles are hygroscopic; they tend to attract the humidity of the environment and stick to the sensor. If used in time, the blower tool will blow away any loose particles in the camera or on the sensor. Cleaning the R9 and R8 is especially easy, as the digital module can be removed and the sensor cleaned either with the blower or, in more difficult cases, with an optical cloth. In the case of the M8, the sensor has to be made accessible by activating ‘sensor cleaning’ in the menu, which opens the shutter. Both cameras benefit from Leica’s solid sensor coating, making mechanical damage highly unlikely.The lens blower is a gentle approach, and sometimes you will need to try something else. However, brushes will often only introduce additional dust into the camera, while compressed air from spray cans or carbon dioxide bottles can damage camera components through pressure and cold. You can make a simple tool yourself by twisting a sheet of lens paper to a point, holding it with a pair of tweezers and using the paper tip to pick particles off the sensor. Alternatively you can draw upon tools such as ....."

(http://www.lfi-online.de/ceemes/page/show/questions_and_answers/#question1)

- Børre
 
Thardy said:
My first experience with sensor dust occurred last week after a trip to a Northern California beach. This is after having the camera for two years.

Now I have to deal with cleaning it.
Click to expand...

:confused: :confused: The first M8-s were delivered in November last year....
 
Just to report. The M8 I got in November was rather dusty in the beginng and had to be swabbed on several occasions for oil splatters and stuck dust. Now it has settled down to just a blow with the Rocket blower from time to time, about the same as my Canons needed. The second body from January is following the same pattern. So - everybody, don't despair. It turns out to be not too much of a problem.
 
I will have to say that dust is not that big of a problem. Most is not even seen at normal f-stops in normal images. The few spots that may show up are cloned out with no problem.

It is important that one not let dust or the fear of dust ruin your digital photography experience. I am also a firm believer in cleaning your own sensor, yet if you feel uncomfortable do it, send it out! I did at first, long ago. After waiting for my new Nikon D1 to return in 3 weeks, the sensor had more dust on it than it left with! That is when I decided to do it for now on.

It is a good feeling to know you can clean your own sensor. I suggest the air bulb, then sensor brush if reuqired and last resort, wet cleaning! The sensor brush cut my wet cleans down to about 10% of what they used to be
 
So maybe the cameras with built-in ultrasonic cleaners are the way to go. Cameras like the Panasonic DMC-L1 or the Leica Digilux 3 equivalent. Or, the Canon DSLR that has this feature--can't think of the model. But then, Gregg Ebhardt says Canons are the worst--while jaapv finds the issue not as simple as all that.

Maybe film is still the answer. You get a fresh sensor with every shot!
 
Rob-F said:
So maybe the cameras with built-in ultrasonic cleaners are the way to go. Cameras like the Panasonic DMC-L1 or the Leica Digilux 3 equivalent. Or, the Canon DSLR that has this feature--can't think of the model. But then, Gregg Ebhardt says Canons are the worst--while jaapv finds the issue not as simple as all that.

Maybe film is still the answer. You get a fresh sensor with every shot!
Click to expand...

Canon sensor shaker = Canon 400D or xTi
 
Best thing of all, of course, is to prevent dust from getting on the sensor. I found that in my case, the main reason for dust on the sensor was the rear lens caps. When the lens is on the camera, the caps sits in the cupboard collecting dust. Dust that inevatbly works its way onto the rear of the lens. And what's worse, putting those caps on and off the lens means that the metal bayonet scrapes bits of plastic loose, which also inevitably end up on the back of the lens.

Mount a polluted lens, click the shutter, and all that stuff gets electrostatically attracted to the sensor..

Since I've started putting effort in keeping the rear lens caps clean, the amount and frequency of dust bunnies has dropped to almost nil.
 
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