Topic: Dust Bunnies (Read 7326 times)

dbarthel · « **on:** January 07, 2003, 12:46:11 pm »

Well, the micro vac came, uses 4-AA batteries. Has micro suction unfortunately. It did suck up the noseeum, but a hair fell off the vac which was too much for it. So back to the blower brush to get rid of the hair. Save your $12.00

SteveS · « **Reply #1 on:** February 09, 2003, 04:20:12 am »

Quote

The only thing that's "safe" is to use a rubber bulb type blower. Activate the camera's "cleaning mode" and with a flashlight in one hand and the bulb in another blow short hard bursts of air at any visible dust spots.

If this doesn't work there are special sensor cleaning swabs available from dealers. Calumet has them, as well as a residue free fluid called Eclipse. Do NOT use canned air. It contains a propellant that can leave residue and also can be too powerful if not used with extreeme care. Whatever you do, don't touch the sensor with anyhting other than a special swab.

Michael

I recently purchased a 1Ds and it came with a significant dust problem. I tried the bulb with no luck. After dicussing the problem with Canon, I have found that other new owners have experienced the problem too.

It seems that Canon should publish an alternative method for removing dust. My guess is that they do not want to sanction the use of anything that could damage the sensor, but the current method just doesn't work...

I will give Michael's method a try - should the swabs be used dry or wet? Dab at the dust or wipe it? Any other hints?...I don't want to make a fatal error!

Steve

Guenter · « **Reply #2 on:** February 15, 2003, 09:56:18 am »

Dear Michael,

I would like to refer to your Luminous Landscape article on digital sensor cleaning.

First, one thing has to be considered when using compressed CO2 or other compressed gas for sensor cleaning: during spraying the compressed gas cools down due to expansion. Anyone can make this experience with cleaning sprays. One can even produce dry ice (temperature_ roughly -110 deg, i.e. -78 deg. C) simply by expanding CO2 from bigger, high-pressure bottles. Chip cleaning by spraying too long may cool down the chip cover material severely and, by generating stress therein, may cause damage. This is the hour of the good old hand squeezed blower bulb.

Second, besides a possible contribution of electrical charge, the higher sensitiy of your D1 to dust particles may be related to two parameters: To the distance of the dust-covered chip-protecting surface to the light-sensitive surface, as well as to the angle of the light cones contributing to individual pixel illumination on the sensor. These two parameters contribute to the "sharpness" of the dust signal, very like the type of illumination and the film holders' glass did in the old days of darkroom enlargers: diffuse, indirect illumination vs. direct illumination (condenser or even spot illumination), the latter producing sharper images, but generating sharp, nasty dust signals on conventional prints.

As a consequence, dust will be more pronounced with a lens producing narrower light cones by design, and if one closes the field stop. This enables the dust particles to absorb or scatter a higher fraction of the light on its way to the target pixels. Likewise, thinner protection covers on the chip's sensitive surface will enhance (sharpen) signals caused by dust. Do you have informations on the chips regarding cover thickness?

One could imagine to take a real unsharp image under identical imaging conditions (at least at the same f stop) if the dust cannot be removed. A neutral diffusor in front of the lens may help to produce such a "background" image. This image, additionally corrected to represent only the dust signals, could be digitally subtracted later on from the orginal image. Such "mottle" removal is common practice in video enhanced contrast microscopy, although probably easier to achieve there (monochrome cameras, constant background etc.). it may be worth a test with digital cameras, if not already done.

Best regards,

Guenter

Nicholas · « **Reply #3 on:** March 09, 2003, 06:10:23 pm »

Hey Michael,
This is my first visit here and I'd like to compliment you on the structure and content of the site.
Your dust maintenance tips are right on the money. I would like to contribute to the discussion a view of my web-site which addresses this topic.
It's quite unbelievable how far ranging the opinions and approaches to CCD/CMOS dust accumulation are. Some people say it is no problem whatsoever and don't care to discuss it. Others, myself included, appreciate the necessity of having NO SPOTS to worry about in post-processing workflow.
My dust maintenance method works great for me and for a growing number of Nikon and Canon users.

CCD/CMOS Cleaning

Again, maybe you'll pick up a tip or two, or, possibly, you'll stick with your own method. Whichever works is fine.
Nicholas

jengwen · « **Reply #4 on:** December 19, 2002, 03:12:38 pm »

[font color=\'#000000\']From 1700 Frames:

Quote

Dust Bunnies
In some 2 years of working with the Canon D30 and D60 dust was seldom a problem. I think that during that time between the two cameras I had to use a blower to remove dust less than a half dozen times. In two weeks of using the 1Ds though I have had to remove dust at least every other day.

I was surprised at this since I was under the impression that CMOS-based chips were less prone to dust than CCDs. This may not be the case, and another factor (or factors) may be at work. Fortunately, and unlike with the D30 and D60, one doesn't need to use AC power while cleaning the chip. Simply set the camera to cleaning mode and press the shutter release. A few squirts with a blower bulb and they're gone. One of the members of the workshop though who was also using a 1Ds ended up with one dust blob that refused to come off and he was going to have to wait till he got back home to use a swab to remove it.

Of greater interest is what I've seen in reviewing the 1,700 odd files. Some show a lot of dust while others seem to be dust free. And this is without cleaning between these frames! I have the impression that the chip becomes charged under some circumstances and attracts dust, and then when conditions change the dust drops off — something like the attraction of static electricity. On the other hand this could be due to the frequent use of high-speed mode when shooting birds. The mirror flying up and down in rapid succession may be causing dust to fly around inside the mirror box, and then it settles down afterwards. I'll be looking into this in the days ahead and will report on what I discover.

One closing thought on the topic of sensor dust. Many newcomers to photography see this as a bigger problem than it really is. In the traditional darkroom "spotting" was (is) a fact of life. Printers would spend hours spotting prints to remove dust and scratches. Those who scan film are well aware that no matter how fastidious one is, dust is an ever-present problem, and one has to become proficient with the cloning tool in Photoshop pretty quickly. The problem of dust on the sensor of a digital SLR is, if anything, much less of a problem than either of these, and with some attention in the field can be minimized.

I have been confused by a small dot that seems to appear and disappear for no apparent reason on some of my D60 shots. I had pretty much decided it was dust, but couldn't figure out why it would not be on every frame. The explanation above makes sense.

I was wondering what the best way is to clean the sensor? I have not had to do it before and am a little nervous about it.[/font]

dbarthel · « **Reply #5 on:** January 02, 2003, 02:49:48 pm »

[font color=\'#000000\']I've just ordered a tiny vacuum cleaner with a brush head like the ruber bulb blowers. I'll post results next week when it arrives. Right now, I have a "bug" on my D60 ground glass screen (a Florida noseeum). Imagine my suprise when the spot moved around in the view finder[/font]

Jonathan Wienke · « **Reply #6 on:** January 12, 2003, 10:30:52 pm »

I am thinking about getting a Nikon D100, (the 1Ds is nice, but way out of my price range) and mid-range zoom lens like the 24-120mm f/3.5-5.6D AF Zoom-Nikkor. If the lens always stays on the camera, shouldn't dust be more or less a non-issue? It would seem to me that most dust contamination would occur while changing lenses. Or am I smoking crack?

max · « **Reply #7 on:** January 14, 2003, 04:51:42 am »

Jengwen,

In response to your main question about the dust spots appearing, disappearing, and appearing again, I believe I may have the answer. I have just recently borrowed a friends D60 for 10 days and shot quite a few frames. In a lot of them there is one annoying "hair" in each shot. But this appears and disappears in different shots. A couple of days ago I was shooting with a Sigma 17-35mm at 17mm with the aperture at 45. When I got home I realized that many shots from the day had a TON of spots on them. After some angry moments, (the next day) I remembered reading somewhere that shooting with a tiny aperture really brought out the spots and shooting "wide open" made them disappear!! It's all dependent on the depth of field. Try shooting with a wide ap. and see what happens...then clean that sensor!

Hank · « **Reply #8 on:** February 09, 2003, 01:43:11 pm »

This may be too obvious, but we have discovered that dust problems go up in direct proportion to the amount of "nooks and crannies" available for it to be trapped in on various models. In essence, using a blower conventionally simply stirs the dust into a new hiding place until it is again dislodged to land on the sensor. On all our DSLR's we have the best luck if we clean them while lying on our backs, usually on a couch, using the blower bulb while holding the body above us with the lens mount pointing straight down. You will be amazed how much more dust comes out when gravity helps, compared to that when the camera is cleaned in a horizontal position. This small change has dramatically cut the frequency of cleaning on all our DSLRs.

JamesMor · « **Reply #9 on:** February 12, 2003, 09:28:03 pm »

When I spoke with a Canon rep at Photo Expo East, he reported to me that the 1Ds has greater dust issues because of the location of the Anti Alias Filter. The fact that the camera has a CMOS chip means nothing.

-JM

JamesMor · « **Reply #10 on:** February 13, 2003, 12:03:00 am »

Hello,

I am not sure. My guess is that the anti-alias filter on the 1Ds is closer - and at the same time is not as strong as the AA on the D60.

-James

Robert Roaldi · « **Reply #11 on:** February 16, 2003, 12:36:19 pm »

Perhaps this is slightly off topic but I noted in MR's original article that Dust Stop used liquid propellents. Somehow, I never knew this. Is there then a reason to avoid its use with lenses as well as digital sensors?

Am I being paranoid?

bill.cb · « **Reply #12 on:** February 16, 2003, 03:13:49 pm »

In addition to the items Michael has written about and which I have been using myself, there is a small vacuum you can buy called Datavac PC. Originally designed for cleaning computers, it is used by museum archivists for delicate work. It has quite a gentle "suck" and I find it better than blowing dust around. It comes with brush tips but I choose not to use them - I'd rather not touch the sensor unless I absolutely have to.
The vac is quite cheap - $20-25 or so, and its only drawback is the need for 120V power.

aatos · « **Reply #13 on:** July 02, 2003, 02:20:35 am »

C0-2 Duster. (from: http://www.americanrecorder.com/catalog/de...t.php?cPath=10)
don't use it, i tried to clean the sensor with it in my Canon EOS-1Ds. first time it was OK,but on second cleaning there came some moisture or oil on the sensor. it was clearly seen by eye and it showed on all pictures like small dark rings with light inside. now the camera is on its way to canon for reparation - i hope that they can clean the sensor, or it will be a new one for 3000 EUR. what a shit luck i had - and the cleaning in canon would be only 38,50 EUR. - bad-luck-
aatos

« **Reply #14 on:** December 19, 2002, 06:13:12 pm »

[font color=\'#000000\']The only thing that's "safe" is to use a rubber bulb type blower. Activate the camera's "cleaning mode" and with a flashlight in one hand and the bulb in another blow short hard bursts of air at any visible dust spots.

If this doesn't work there are special sensor cleaning swabs available from dealers. Calumet has them, as well as a residue free fluid called Eclipse. Do NOT use canned air. It contains a propellant that can leave residue and also can be too powerful if not used with extreeme care. Whatever you do, don't touch the sensor with anyhting other than a special swab.

Michael[/font]

« **Reply #15 on:** January 13, 2003, 05:01:42 am »

Of you never remove the lens then you won't have dust issues. But I have to say that this would be like never shifting out of first gear.

A selection of focal lengths is what most photography is about.

Michael

Peter McLennan · « **Reply #16 on:** February 12, 2003, 11:31:32 pm »

the "location of the anti-alias filter" being what? Closer to the sensor's surface? Hence more in focus?

Peter

Dean · « **Reply #17 on:** February 16, 2003, 12:53:51 pm »

This may be a crazy idea, but has anyone tried to use a scuba tank and regulator as an air blower to clean film and cameras? I am a scuba diver and I know that the air in the tanks should be very dry and highly filtered. You would need to replace the mouth piece of your regulator with a small nozzel with a squeeze trigger. One small tank of air should last a very long time when used for cleaning. I haven't tried this idea, but maybe it would work.

Nicholas · « **Reply #18 on:** July 03, 2003, 10:11:52 pm »

Hi Everyone,
Just some points to add to the discussion:

*The only object that touches my CCD is a methanol moistened PecPad. No brushes of any kind and no stuff- grabbers or lens pens. Many people have stated that these things deposit tons of gunk on the sensors.

*As far as holding the camera upside down to use gravity to escort dust out of the chamber, have you ever seen early morning or late afternoon sunlight streaming into your house? The dust particles that are illuminated are much bigger than those that are attracted by the sensor, and they seem to have no problem at all "floating" and even RISING all by themselves. So, while some of the dust may be blown off your sensor and may even exit, much more dust may remain in the chamber either airborne or coming to rest in one of the many nooks and crannies. In my opinion, this is the reason blowers don't work very well and perform very inconsistently.

*The AA filter on the 1Ds and 10D has been moved closer to the CMOS, which may explain why they attract and show much more dust than the D30 or D60.

*Re: CO2 blowers, see post by "aatos" above.

Nicholas
CCD & CMOS Cleaning

Author Topic: Dust Bunnies (Read 7326 times)

dbarthel

max

JamesMor

JamesMor

Robert Roaldi

aatos

Dean