Dust on sensor

Rita Ä Berkowitz wrote:

Jørn Dahl-Stamnes wrote:

I have tried that. I have used a cleaning agent from Visible Dust
several times. No luck. The dust look exactly the same as before I
began cleaning the sensor.

One suggestion you might want to try. Take a Pec-Pad and add one drop of
distilled water to the pad and hit the sensor this. This hopefully will
dissolve what the cleaning agent (methanol) didn't. Methanol doesn't
dissolve everything water can. Once this is done follow with a new
Pec-Pad with he cleaning agent and this should do it.

And if the cleaning agent is water-based? It should dissolve it. But maybe
sensor need to be exposed to the cleaning agent for a longer time?

--
Jørn Dahl-Stamnes
http://www.dahl-stamnes.net/dahls/

Jørn Dahl-Stamnes wrote:

Rita Ä Berkowitz wrote:


Jørn Dahl-Stamnes wrote:


I have tried that. I have used a cleaning agent from Visible Dust
several times. No luck. The dust look exactly the same as before I
began cleaning the sensor.

One suggestion you might want to try. Take a Pec-Pad and add one drop of
distilled water to the pad and hit the sensor this. This hopefully will
dissolve what the cleaning agent (methanol) didn't. Methanol doesn't
dissolve everything water can. Once this is done follow with a new
Pec-Pad with he cleaning agent and this should do it.


And if the cleaning agent is water-based? It should dissolve it. But maybe
sensor need to be exposed to the cleaning agent for a longer time?

Perhaps it is a dust spot between the top glass filter and the sensor.
What camera do you have? I've wondered about the new cameras
that ultrasonically vibrate the IR filter: could dust work its way
under the filter? How well are the seals around the filters
over the sensor?

Roger

Ockham's Razor wrote:

I do not remember what camera is being discussed here, but why not just
send it to the manufacturer for servicing?

Because I will be without a camera for days... :-(

--
Jørn Dahl-Stamnes
http://www.dahl-stamnes.net/dahls/

Roger N. Clark (change username to rnclark) wrote:
Perhaps it is a dust spot between the top glass filter and the sensor.
What camera do you have? I've wondered about the new cameras
that ultrasonically vibrate the IR filter: could dust work its way
under the filter? How well are the seals around the filters
over the sensor?

It is a Canon 30D, one year old.

It have had the same thought - maybe it is between the glass filter and the
sensor, since it seem to be more 'in focus' than other dust particles that
I have seen before.

--
Jørn Dahl-Stamnes
http://www.dahl-stamnes.net/dahls/

M-M wrote:

In article ,
Jørn Dahl-Stamnes wrote:

maybe it is between the glass filter and the
sensor, since it seem to be more 'in focus' than other dust particles
that I have seen before.


At small apertures, dust particles on the surface of the low-pass filter
are perfectly in focus.

Here is a cropped image that shows the dust.

http://www.dahl-stamnes.net/Foto/dust.jpg

The image show two spots on in the image. The problem spot is marked 1. Spot
2 came after the last wet cleaning of the sensor, and was removed by using
compressed air.

--
Jørn Dahl-Stamnes
http://www.dahl-stamnes.net/dahls/

Jørn Dahl-Stamnes wrote:

M-M wrote:

In article ,
Jørn Dahl-Stamnes wrote:

maybe it is between the glass filter and the
sensor, since it seem to be more 'in focus' than other dust particles
that I have seen before.


At small apertures, dust particles on the surface of the low-pass filter
are perfectly in focus.

Here is a cropped image that shows the dust.

http://www.dahl-stamnes.net/Foto/dust.jpg

The image show two spots on in the image. The problem spot is marked 1.
Spot 2 came after the last wet cleaning of the sensor, and was removed by
using compressed air.

And here is a 100% crop image:

http://www.dahl-stamnes.net/Foto/dust_full.jpg

--
Jørn Dahl-Stamnes
http://www.dahl-stamnes.net/dahls/

Jørn Dahl-Stamnes wrote:
And here is a 100% crop image:

http://www.dahl-stamnes.net/Foto/dust_full.jpg

Wopps. I ment a full image.

I have also searched through old pictures and I can find a spot at the same
place as #1 in the image as far back as October 12, 2006. But at that time
the spot was more like the #2 stop. It seems like the spot has changed over
time.

Someone has suggested dead pixels, but since the spot is not longer visible
at aperture 10 or lower (down to 2.8), it cannot be a group of dead pixels.

--
Jørn Dahl-Stamnes
http://www.dahl-stamnes.net/dahls/

In article ,
Jørn Dahl-Stamnes wrote:

Ockham's Razor wrote:

I do not remember what camera is being discussed here, but why not just
send it to the manufacturer for servicing?

Because I will be without a camera for days... :-(

A small price for getting it done right once and for all.

--
"When fascism comes to America, it will be wrapped in the flag and
carrying a cross."
Sinclair Lewis

On Feb 28, 10:39 am, Ockham's Razor wrote:
In article ,
Jørn Dahl-Stamnes wrote:

Ockham's Razor wrote:

I do not remember what camera is being discussed here, but why not just
send it to the manufacturer for servicing?

Because I will be without a camera for days... :-(

A small price for getting it done right once and for all.

--
"When fascism comes to America, it will be wrapped in the flag and
carrying a cross."
Sinclair Lewis

Are you SURE that's not a pixel artifact? In a JPEG, one pixel can
spread out over a small square of compression, and look like that. Can
you take a tiff image instead?

My other thought would be to IGNORE it! Its nothing!

DeanB wrote:

On Feb 28, 10:39 am, Ockham's Razor wrote:
In article ,
Jørn Dahl-Stamnes wrote:

Ockham's Razor wrote:

I do not remember what camera is being discussed here, but why not
just send it to the manufacturer for servicing?

Because I will be without a camera for days... :-(

A small price for getting it done right once and for all.

--
"When fascism comes to America, it will be wrapped in the flag and
carrying a cross."
Sinclair Lewis

Are you SURE that's not a pixel artifact? In a JPEG, one pixel can
spread out over a small square of compression, and look like that. Can
you take a tiff image instead?

Yes, I'm sure. I shoot RAW files only. The jpeg file I put on my web-server,
is created with PhotoShop and the RAW converter.

I also came across this page:

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

The term "Welded dust" is used. It seems to the right definition to my
problem.
Any comments on what is best - water bases or methanol based solution to
clean the sensor if it is a welded dust?
--
Jørn Dahl-Stamnes
http://www.dahl-stamnes.net/dahls/