Dust on sensor, Sensor Brush = hogwash solution?

Clyde wrote:

Alan Browne wrote:

It's a good question, but think about it. If you 'blow' then as I
said, you just move things around, usually deeper in the camera.
Further, if you blow something out, then something has to replace it
(no different than a vacuum).

Some time ago I described in detail how to make a simple low pressure
vacuum system that would also reduce ambient dust from entering the
camera. (Note that dist does not settle easilly when there is airflow).

http://tinyurl.com/66epq

Cheers,
Alan


If you blow, you move particles around. I understand that. I'm just
saying that sucking should also move particles around. Any movement of
air inside your camera would move particles around. Then again, that is
the point - isn't it? You are trying to move particles off of your sensor.

Yep, but particles that fly up the hose are gone.
particles blown around the sensor chamber are still around.

Just do the work in a low dust environment which anyone can create reasonably.
A clean room is not required.

You have a creative method to control the amount of air that is moving,
but I don't see the point. If you blow or suck at different rates, you
still have to move air to move the particles. High speed air movement
just does it faster than low speed air movement.

Who said it has to be high speed? Read what I posted at the link above and
adjusting the airflow for a low rate. Gentle. The airflow at the small nozzle
will be low, and airflow coming into the camera to replace much lower.

I'm sure that very low speed air movement (blowing or sucking) will move
some particles off of your sensor. If you don't move the air fast, those
particles aren't likely to be moved far. That would protect them from
going deep into those mythically dangerous places deep into your camera.

"Mythically dangerous?" Go talk to some old photogs and old repair guys about
where they find dust in cameras and how it eventually gobs up the mechanics.

The question is, do they move far enough? Is the air movement hard
enough to move all the particles, even ones that are semi-stuck on the
sensor? If you move enough air to move the particles, what is to stop
other particles from moving back on the sensor? I know that dust doesn't

As I say above, the small vacuum nozzle will have a low flow. The air replacing
it coming into the camera will be much-much lower.

settle easily when there is air flow, but at some point the air has to
stop flowing. (Hum, there's an idea... continuous air flow across the
sensor.) When it does stop, wouldn't dust resettle?

I sincerely suggest that you're making this more complicated than it need be.
As the Nikon site suggests, use a brushless blower and good luck. Add that to
the doohickey I describe above and you will have very little dust in the camera.

Therefore, I still don't see how sucking is any better than blowing. I
also don't see how either of them removes all the dust particles off the
sensor. Well, unless you do this in a dust-free environment - which I
certainly do not have.

As I said, a vacuum and a brush. One dislodges, the other removes. Nikon say
"don't use a brush" so you goota decide what is the right thing to do.

Nobody has a dust-free environment. Even clean rooms have so many particles per
m^3. Put your camera in a small closed room over night. Let the dust settle.
Go in gently and clean it. Buy a precipitator to move most of the dust to the
floor. If the room has forced air heating/air, shut the vent off.

Use common sense, IOW. Which, as another poster suggests, includes a regular
cleaning out of the camera bag.

Over-and-out.

Cheers,
Alan

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http://www.bythom.com/cleaning.htm

Jason P. wrote:

Hahaha... Canada is the second largest country on the face of the planet!
That's like saying "You're from the USA... you must be working for NASA".

You want to look at Nikon's own article on cleaning a low pass filter?

http://support.nikontech.com/cgi-bin...ted=1053089297

See the part there that says "The use of a blower-brush is not recommended
as the bristles may damage the filter ... Under no circumstances should the
filter be touched or wiped."

And then the Minolta 7D manual, (Same sensor as D70, not sure about
anti-aliasing filter), p110.

"Clean the CCD in a dust-free environment. Use a blower brush to remove the dust
- compressed air can damage the camera."

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-- e-meil: there's no such thing as a FreeLunch.

Doug Payne ( ) wrote:

http://www.bythom.com/cleaning.htm

Gawd! Another Canadian sock puppet pointing us to a site that encourages
the use of the criminally overpriced "Sensor Brush"(TM).

Methinks someone is panicking about losing his lucrative franchise!

By the way: Does anyone know for certain what method the Factory
Technician will use when I chicken out completely and send it in for
service?


I've seen some tech manuals on the Net. It looks like Nikon uses something
like wooden chopsticks and a pad and fluid. They work in a circular pattern
from the center to the outer edges. I'm guessing the kits they sell for
cleaning the CCD is about as close as you can get to how the factory does
it. And the small rubber spatula you wrap the pad around would seem to be
far safer than using something stiff like wood.

And, for my two cents, I doubt a vacuum is as good as a blower. The vacuum
would have to be very close to the sensor and the particle would have to be
very loose for the vacuum to pull it off. A blower will dislodge the
particle with a puff of air, and hopefully blow it completely out of the
camera. In a perfect world, you would use both at the same time; a blower
to knock the particle loose, and a vacuum to get it out of there.

In article ,
Sheldon wrote:
By the way: Does anyone know for certain what method the Factory
Technician will use when I chicken out completely and send it in for
service?


I've seen some tech manuals on the Net. It looks like Nikon uses something
like wooden chopsticks and a pad and fluid. They work in a circular pattern
from the center to the outer edges. I'm guessing the kits they sell for
cleaning the CCD is about as close as you can get to how the factory does
it. And the small rubber spatula you wrap the pad around would seem to be
far safer than using something stiff like wood.

Agreed.

And, for my two cents, I doubt a vacuum is as good as a blower. The vacuum
would have to be very close to the sensor and the particle would have to be
very loose for the vacuum to pull it off. A blower will dislodge the
particle with a puff of air, and hopefully blow it completely out of the
camera. In a perfect world, you would use both at the same time; a blower
to knock the particle loose, and a vacuum to get it out of there.

The discussions of the various cleaning methods and the
associated problems has set me to thinking. As a result, I have been
considering fabricating a special device for the function which does
combine the two functions in a single device.

It would consist of a pair of concentric tubes, with a vacuum
pulled on the inner tube, and (lightly) compressed air in the outside.
The ring at the end would be drilled with multiple holes at an angle
towards the center.

The idea would be that the particles dislodged by the gentle
airflow would be blown towards the center of the pattern by all of the
converging air jets, and be picked up by the vacuum in the central tube.

The incoming air would go through a small HEPA filter such as is
used in medium sized disk drives (also *very* sensitive to dust
particles) prior to being directed down the outer tube. The air, before
the HEPA filter would be split into two paths, one to the HEPA filter
and the outer tube, and the other through a venturi to generate a
vacuum. The venturi's vacuum port would be connected to the inner tube.
There would be a pair of needle valves to adjust both airflows.

To set the two needle valves, you would first adjust the one to
the outer tube to give the desired airflow for a gentle brush-off. Then
a balloon would be slipped over the outer tube (with a bit of a leak so
the balloon would not fully inflate and burst. Then the needle valve to
the venturi would be adjusted so the balloon would hold a given slack
size, even if the neck is pinched tightly around the outer tube. This
would assure that the net flow into and out of the camera body through
the device would be zero, so you would not be drawing dust-laden air
into the camera body while cleaning.

Obviously, the end of this device would have to be made of a
material soft enough to be unlikely to damage the sensor covering, and
neutral enough to not contaminate it. At first thoughts, I think that
Teflon would be a good choice for that. The total diameter of the probe
would be 1/4" or perhaps 3/16" (6mm or 4.75mm roughly, for the
metric-inclined among you).

Any opinions about this device?

Enjoy,
DoN.

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Any opinions about this device?

Will it fit through the door?

I have a D70. I've read the various blurbs, advertising and otherwise,
about cleaning the "sensor." With several decades of experience in cleaning
rooms and objects of various sizes, I'd like to suggest that "removing" dust
by blowing it around with a bulb or brush is not effective in the long run.

Having read Nikon's advice and that of those selling swabs, fluids,
etc., I'd be very interested to know what the low-pass filter is made of--
synthetic, glass or what? Fact is, if you attempt to take the job on
yourself, what you're swabbing is the filter, not the CCD.

"MB" wrote in message
...
SNIP
Having read Nikon's advice and that of those selling swabs, fluids,
etc., I'd be very interested to know what the low-pass filter is
made of-- synthetic, glass or what? Fact is, if you attempt to take
the job on yourself, what you're swabbing is the filter, not the
CCD.

This is an example of a Canon multilayer low-pass filter:
http://www.canon.com/technology/deta...ter/index.html
Although they don't specify the material used, it is possibly Lithium
Niobate.

The swabbing/brushing will take place on the dichroic mirror coating
on the IR absorption glass.

Bart

Bart van der Wolf wrote:

"MB" wrote in message
...
SNIP

Having read Nikon's advice and that of those selling swabs, fluids,
etc., I'd be very interested to know what the low-pass filter is made
of-- synthetic, glass or what? Fact is, if you attempt to take the
job on yourself, what you're swabbing is the filter, not the CCD.


This is an example of a Canon multilayer low-pass filter:
http://www.canon.com/technology/deta...ter/index.html
Although they don't specify the material used, it is possibly Lithium
Niobate.

The swabbing/brushing will take place on the dichroic mirror coating on
the IR absorption glass.

Bart

Thanks, this gets to the heart of the matter. The nylon brush hairs will
be touching a dielectric coated interference mirror. Read about them
here http://optics.unaxis.com/en/Dichro_548.asp (attached pdf there is
good).

The manufacturers claim that such mirrors have the "highest scratch and
mechanical resistance" and are made, inter alia, of "heat resistant
borosilicate glass". I'm not sure if this is the exact sort of dichroic
mirror on the typical dSLR sensor, but if it is, the concerns so far
voiced by people like the Canuck "Jason P" seem absurd.