Avoid dust on sensor

[J.M. KLEES]

How can I avoid getting dust inside the chamber and on the sensor when changing lenses under field condition?

[dialdn]

I turn the camera off and point it down. In that case, gravity and static are minimized. Not sure how much static is created with camera on but I would think it doesn't hurt to have it off.

D

[Cadwell]

How can I avoid getting dust inside the chamber and on the sensor when changing lenses under field condition?

The simple answer is that you can't. You'll just have to get used to cleaning the sensor etc. occasionally. One of the trials of dSLR ownership.

[Leorooster]

The question is how often the sensor needs to be cleaned?

[Curtis N]

"I am the wisest man alive, for I know one thing, and that is that I know nothing." --Scrates--

Who is Scrates?

[pierrot]

A phil's'pher 'f w'hm Plat''n was f'nd 'f! :mrgreen:

[Leorooster]

Should be Socrates, not "scrates" - I had a typo there. Anyway, he is an ancient Greek philosopher, and one of the greatest philosophers in history.

"I am the wisest man alive, for I know one thing, and that is that I know nothing." --Scrates--

Who is Scrates?

[Jim_T]

I've had my 10D for a year and a half.. I worried about dust at first, but soon learned to live with it.. I've found that the less I worry about dust, the less I get... ( I don't know how this works.. but it really does :) )

I don't do anything special when I change lenses.. (And I change lenses a lot).. I've only had to clean my sensor four times in a year and a half.. That's once every 4 months or so.. No big deal..

[ed2day]

I always thought the notion of holding your camera upside down was kind of silly. I know, Canon recommends it, but it just doesn't pass a common sense filter. If gravity had a significant impact on dust then there wouldn't be any dust in the air to worry about. Just watch dust in the air--does it steam down to the ground like rain, or does it hang suspended with random motion? For whatever insignificant benefit there may be it's not worth risking dropping your lens by changing it in an akward position.

[Curtis N]

Should be Socrates, not "scrates" - I had a typo there. Anyway, he is an ancient Greek philosopher, and one of the greatest philosophers in history.
Forgive my sarcasm. I pretty much knew the answer. I hated to see a great quote ruined by careless typing. :)

[Leorooster]

No. If you didn't mention, I would not notice the typo. Thanks.Forgive my sarcasm. I pretty much knew the answer. I hated to see a great quote ruined by careless typing. :)

[R1 Kid]

I don't worry about it much. But I do hit both the camera and the lens with a rocket blower between every change. At least I try.

[ddelallata]

No. If you didn't mention, I would not notice the typo. Thanks.

I noticed it last week, but I didn't wan't to seem like an A-hole about it. I'm glad to see that you didn't take it the wrong way :)

[Leorooster]

Sure, I'm the wisest man alive....;) ;) ;)

I noticed it last week, but I didn't wan't to seem like an A-hole about it. I'm glad to see that you didn't take it the wrong way :)

[wibbly]

I always thought the notion of holding your camera upside down was kind of silly. I know, Canon recommends it, but it just doesn't pass a common sense filter.

Ah, now that would be cool. A common sense filter. I wonder what colour one of those would be? :rolleyes:

J

[KennyG]

How can I avoid getting dust inside the chamber and on the sensor when changing lenses under field condition?

As Cadwell has already said, you can't so don't get paranoid about it. I use a Rocket blower after each shoot and in a year I have only had to 'wet' clean the sensor once for one of my two cameras. Just get into the habit of blowing the dust off the sensor as soon as you get back from a day in the field. Cadwell and I work in very dusty, sometimes wet or oily environments at motor racing circuits and simply can't afford the time to be ultra-cautious when changing lenses.

[lomond]

Just watch dust in the air--does it steam down to the ground like rain, or does it hang suspended with random motion?

That's what I say but will my wife listen to me.....no I still have to dust.

Apart from that static might have some say in this.

Listen to KennyG and when you have to wet clean do it. It's not that difficult.

[gasrocks]

I didn't get very far around here but maybe you could try at your house: You need a dedicated body for each lens. If you never remove the lens......

[am_pitbull_terrier]

I noticed it last week, but I didn't wan't to seem like an A-hole about it. I'm glad to see that you didn't take it the wrong way :)

It only took 277 psots for soemone to say someting;)

I can't say anyting though, I didn't notice it was pointed out now.

[Leorooster]

:o :o Not quite.....I didn't have the quote in my first......maybe 50 posts.......;) ;)



It only took 277 psots for soemone to say someting;)

I can't say anyting though, I didn't notice it was pointed out now.

[CyberPet]

I found a speck on my viewfinder matte (or whatever you call it), so I tried to clean it with blowing some air with one of my old lens cleaner bulbs... well, I got the dust speck to move, but not out of the way... (at least it didn't get worse). So now I wonder how bad it might be on the sensor.

I don't want to send my camera in to get it cleaned... is it wise to use those sensor brushes you charge with canned air, or should you try to avoid anything touching the sensor - at all?

[Cadwell]

First, can you see dust in your pictures? If you can't then don't worry about it.

If you can then first try the blower bulb technique as recommended in the Canon manuals. If that doesn't work then try the Copperhill Method (http://www.pbase.com/copperhill/ccd_cleaning).

[CyberPet]

Well, I did see lots of dust when I shot some pics with f/26 (but that's not something I do all days to say the least), so I think it's even worse now, that was 1.5 month ago and many lens changes later.

I've seen that site before... but which one is the best?? Have anyone of you tried any of them and can say "no, avoid this, but get that" or something?

[Gogu]

Just get into the habit of blowing the dust off the sensor as soon as you get back from a day in the field

I have a rocket blower too (if you were reffering to blowing the sensor with it), but isn't the sensor covered by the mirror? Or you put the camera on sensor cleaning mode?
And isn't it dangerous to blow air direclty from the blower into the sensor? I mean the air can be pretty powerful coming from the blower and it might do some damage.
And isn't the air from the outside also filled with dust particles so whats the use of blowing dust on dust?

What is the best way to see if you have dust on your sensor?I read somewhere that taking a shot of a white sheet of paper should reveal the dust. Is it better that i take it with a smaller aperture or with a larger one?

Sorry for all the questions but they just sat on my brain begging to be asked!
:p

[BobL]

I always thought the notion of holding your camera upside down was kind of silly. I know, Canon recommends it, but it just doesn't pass a common sense filter. If gravity had a significant impact on dust then there wouldn't be any dust in the air to worry about. Just watch dust in the air--does it steam down to the ground like rain, or does it hang suspended with random motion? For whatever insignificant benefit there may be it's not worth risking dropping your lens by changing it in an akward position.

Having built 2 ultraclean low dust labs and worked for decades in more than dozen I guess I know something about dust. Firstly gravity does matter, especially for bigger particles which are the ones that will cause senor problems. We even test our labs by leaving 15 mL teflon beakers open around the lab and collecting dust fallout over a period of weeks. Yes the dust does swirl around but at any one time more of the big particles are going down than up

I don't have my own DSLR (yet, soon hopefully) but am surprised that no one has suggested using a clean antistatic bags to store and change lenses in. I have no idea how easy this would be in practice but it would have to reduce the probability of lens/sensor dust contamination, especially in really dusty environments.

I know a lot of users don't care about this and can also understand that this will not be practical for photographers who are used to changing lenses quickly and/or are able to clean their own sensors.

[wibbly]

surprised that no one has suggested using a clean antistatic bags to store and change lenses in.

May well help, but of course cameras are not air and therefore dust tight even with their lenses on. I guess it's all about particle size?!

J

[BobL]

May well help, but of course cameras are not air and therefore dust tight even with their lenses on. I guess it's all about particle size?!

J

Good point - dust free rooms typically work on an overpressure principle to keep dust out. As the camera is carried from high to low pressures ie different heights above sea level or even as the atmospheric pressure naturally changes the sensor cavity will "breathe". However, the sorts of particles that will get through this "breathing" process are likely to be sub pixel size and should not effect the image quality that much.

I guess it demonstrates that keeping the camera clean as much as possible could be worth while and (another feature about dust free clean rooms) using a multiple barrier approach will help keep it clean ie two plastic bags should be much better than one.

NB: usual dust caveats apply.

[CyberPet]

Gravity... would it help to change lenses with the camera body pointing downwards? And make sure you don't stand in wind. Oftentimes I find myself having to change lenses outdoors.

[Tom W]

I always thought the notion of holding your camera upside down was kind of silly. I know, Canon recommends it, but it just doesn't pass a common sense filter. If gravity had a significant impact on dust then there wouldn't be any dust in the air to worry about.

On the other hand, how many times do you find the need to dust the bottom of the table. :)

That said, you will get dust on the sensor regardless of which angle you hold the camera. Probably more facing up, but I doubt if the difference is significant. Dust will settle in a downward fashion, but is also light and fluffy enough to remain airborne for quite a while.

The good thing about the airborne dust that might find its way to the sensor/filter glass is that it is looser, and easier to remove with the simple Giotto's rocket blower. Be sure to purge the blower before you do your cleaning ritual and do hold the camera face down for the cleaning portion of the ritual. At this point, the fear of dropping a lens is minimal since the lens is not on the camera.

[J.M. KLEES]

:p Thanks guys. jmk

[ed2day]

I seem to be outnumbered, but I'm not convinced. Of course dust settles over the course of a day, or a week, but the question is how fast it falls over the course of one second to change your lens (or much less if you're quick). I maintain that the movement of dust due to gravity in that time frame is totally swamped out by the air currents of just removing/replacing your lens. My point is it's just not worth the risk to expensive equipment by fumbling with it upside down, even for a small advantage. I would probably think differently if I was in an evironment that was kicking up dirt. Oh well, whatever works for you...go with it.

[BobL]

I maintain that the movement of dust due to gravity in that time frame is totally swamped out by the air currents of just removing/replacing your lens.
Sorry to labour this but our experience in ultraclean rooms is that even in turbulent areas where the air moves upwards about as much as downwards, collection surfaces facing downwards collect significantly less dust than if facing upwards. What happens is that even in turbulent air, thin layers of still air occur at or near surfaces. If any dust enters this layer gravity takes over. In an downward facing surface dust continually falls out of this layer away from the surface whereas upwards facing surfaces do the opposite

The biggest injection of dust into the sensor-mirror-lens cavity is most likley to occur when air (and dust) is pulled into this cavity by the mere act of removing the lens. If the lens is removed with the camera facing down most of the incoming dust will (hopefully) fall out of this cavity, whereas if the camera is facing up, more will stay there to settle out on the sensor.

My point is it's just not worth the risk to expensive equipment by fumbling with it upside down, even for a small advantage.
I agree there are many times when prudence is a virtue. I still remember 30 years ago trying to keep my feet on a bucking boat while changing an SLR lens and trying to keep the body facing towards me to stop wind spray getting on the mirror. The zoom rolled across the deck and was about to drop over the side when the boat pitched the other way and virtually threw the lens back at me.

[ed2day]

Bob,
What you say makes some sense. I remember something about zero-velocity boundary layers from fluid dynamics. You're the dust guru, maybe I should reconsider--Nah, still too worried about dropping my lens!Thanks for your input.

[BobL]

Bob,
What you say makes some sense. I remember something about zero-velocity boundary layers from fluid dynamics. You're the dust guru, maybe I should reconsider--Nah, still too worried about dropping my lens!Thanks for your input.

Cheers, Actually I won't really be satisfied until I measure it myself. when I have nothing much else to do I'm going to try changing a lens outside the clean room (pointing the body up) and then going inside the clean room, popping a lens and measuring the dust coming out of the sensor cavity with a particle counter. Then I'll test dust entry on lens changing with body pointing down. Then I'll post my results. I just love doing geeky stuff like that. You should see me with a bunch of temperature sensors strapped to an espresso machine all connected up to a laptop and measuring x, y and z while pulling a coffee and then posting on Coffeegeek dot com.

[Jon]

In order for the "hold it with the opening facing down" theory to work, the dust would have to fall completely out of the mirror box before you get the new lens in position, and you'll still be holding the lens "facing up", and able to collect dust which could be stirred up by the mirror slap as you photograph. I think that's just one of those things that sounds reasonable, but doesn't hold up to examination. One might also theorize that holding the camera and lens perfectly horizontal, so the exposed open surfaces are vertical and any settling dust would not be able to land on either, would be the optimum method.

Me, I just hold it however works for where I'm working. Usually I just leave the body on its strap around my neck, in whatever attitude it ends up hanging.

[Tom W]

Sorry to labour this but our experience in ultraclean rooms is that even in turbulent areas where the air moves upwards about as much as downwards, collection surfaces facing downwards collect significantly less dust than if facing upwards. What happens is that even in turbulent air, thin layers of still air occur at or near surfaces. If any dust enters this layer gravity takes over. In an downward facing surface dust continually falls out of this layer away from the surface whereas upwards facing surfaces do the opposite.

The biggest injection of dust into the sensor-mirror-lens cavity is most likley to occur when air (and dust) is pulled into this cavity by the mere act of removing the lens. If the lens is removed with the camera facing down most of the incoming dust will (hopefully) fall out of this cavity, whereas if the camera is facing up, more will stay there to settle out on the sensor.

This lends credence to the idea that the front of the camera near the lens mount should be kept rather clean. I have heard of people brushing the lens-camera interface before removing the lens. Don't know if that helps or not, but I'd rather have the dust away from that opening than in it.

I change a lot of lenses in the car and I do take care to keep the camera pointed downward. Nevertheless, I occasionally need to use the rocket blower on the sensor (be sure to purge the blower a few times before using it - one member here was greeted to a sloppy spray of moisture from his blower due to internal condensation). It really isn't a big deal if the dust is merely airborne dust.

I agree there are many times when prudence is a virtue. I still remember 30 years ago trying to keep my feet on a bucking boat while changing an SLR lens and trying to keep the body facing towards me to stop wind spray getting on the mirror. The zoom rolled across the deck and was about to drop over the side when the boat pitched the other way and virtually threw the lens back at me.

A good reason to sacrifice your credit card at the alter of EOS, god of the Lens. :)

[Tom W]

Cheers, Actually I won't really be satisfied until I measure it myself. when I have nothing much else to do I'm going to try changing a lens outside the clean room (pointing the body up) and then going inside the clean room, popping a lens and measuring the dust coming out of the sensor cavity with a particle counter. Then I'll test dust entry on lens changing with body pointing down. Then I'll post my results. I just love doing geeky stuff like that. You should see me with a bunch of temperature sensors strapped to an espresso machine all connected up to a laptop and measuring x, y and z while pulling a coffee and then posting on Coffeegeek dot com.

Repeat the experiment many times to make it statistically supportable. Test other environments as well - my car would not be considered anything close to a "clean room". It's my living room at times, when it isn't serving as my kitchen.

[Huckaback Photo]

J M KLEES
Welcome to the forum.
I posted this on a previous thread and thought it might be of interest here.
...........................................
"An extra tip for anyone that would like to blow dust around inside you Digital camera body or lens.
1...fit the 100 to 400 L zoom to the body. (its push-pull zoom, if you dont own this lens)
2... hold the lens barrel and rapidly push /pull the zoom in and out several times.
3... if any dust inside lens or body I guarantee it will move it around.

if you were to try this with the lens off you can indeed feel the air being forced out from back of lens.
how did I learn this you may well ask.
From a Canon Rep !! showing me how to move a speck of dust inside my 100 to 400 L .
by pumping it a few times he actually made it worse, finished with 5 specks,
oh well live and learn I guess.
truth is a few small specks in any lens will never really affect performance.

Cheers
Martin (Huckaback Photo)

PS. How about a new sticky...
Golden rules for SLR digital bodys
1..never blow on a sensor to clean it.
2..never leave body without body cap or lens fitted.
sure you guys have many more."
.....................................
I really posted this to show there are other ways of getting dust on our sensors even with a lens attached.
I'm sure that many on here realise certain lenses are in fact weather/dust sealed.
ie.. some of the more recent "L series". So if your working in bad conditions this would help, also note the 1 series D SLR bodys are also fitted with weather proof seals around many switches and buttons.
Often we read comments about their kit lens is just as good a performer as the more expensive "L lens" this may well be true at times, it is also build quallity we are paying for, does a lesser lens have a rubber seal on its mount ? NO.

I think common sense plays a big part in keeping the insides of both camera and lens clean.
we have just seen images on here from an Australian Rally , complete with loads of dust behind the cars. not a good place to swap lenses.
DO NOT put a body or lens down without a body / lens cap fitted.

Finally has anyone here been into a camera shop, asked to try a D SLR with certain lens.We then see shop assistant place the camera body on the counter without lens or body cap and face up !!
Sorry I don't want to buy that one , get one in a sealed pack.
Forum members have often said they have muck on the sensor from new...However could that happen ???

Cheers
Martin (Huckaback Photo)

[2new]

"Dust Happens"