# Dust With Long Exposures (advice please!)



## GeorgeUK (Mar 6, 2008)

Out shooting today and noticed that on longer exposures 1sec + what I can only assume to be dust was apparent in the top left of the image.

Swapped over the lenses to check it wasn't a prob with these, same prob, so I can only reason it's in the body.

The odd thing is, the dust doesn't show up on quick shutter speeds, only the longer ones.

I'm assuming this is dust on the sensor (so much so the 400d's sensor cleaning!). If I take it to a camera shop, can they sort this? If so how much will it cost?

Quite annoying.


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## Big Mike (Mar 6, 2008)

Dust on the sensor is just a fact of life with DSLR cameras.  They need to be cleaned once in a while.

Shutter speed doesn't directly affect the dust spots (although long shutter speeds can give more noise)...but the aperture does affect how dust shows up.

If you use a wide aperture (which may give you a faster shutter speed), the DOF will be shallow and the dust won't show up as much.
If you use a small aperture (high F number) the DOF is deeper and the dust is more defined in the image.  To really test for how much dust you have...shoot a blank wall at F22.

Cleaning the sensor is something you can do yourself with a little bit of care and common sense.  Search the forum, sensor cleaning has been discussed many, many times before.


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## GeorgeUK (Mar 6, 2008)

Big Mike said:


> Dust on the sensor is just a fact of life with DSLR cameras. They need to be cleaned once in a while.
> 
> Shutter speed doesn't directly affect the dust spots (although long shutter speeds can give more noise)...but the aperture does affect how dust shows up.
> 
> ...


 
Of course, you are absolutely right. :thumbup: My bad. I had it in Av, it makes full sense that it is owing to the DOF rather than the exposure time.

Silly George. :blushing::blushing::blushing:

I'll have a search and see what I can do. Worried I'd make it work. Is it a matter of buying special tools (cleaning fluid etc?) or just taking one's time?

Thanks once again. :hail:


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## Mav (Mar 6, 2008)

Yeah most sensor cleaning systems are just sales gimmicks from what I've seen.  I've got some on my D80, but you can barely even see them even at f/11 so I don't even worry about it.  All I've needed in almost 19,000 shots on my D80 is just a little rocket blower bulb from time to time and that's it.  Just be careful and don't do anything stupid and you'll be fine for the most part.


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## Big Mike (Mar 6, 2008)

The easy way is to use a blower bulb (not compresses air) and just blow the dust out.

For more 'stuck on' type stuff...you do need to use something more specific.  It could be a type of dust brush (Arctic Butterfly) or more commonly a sensor swab of some time.  With the swabs, you use a fluid like Eclipse.


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## GeorgeUK (Mar 6, 2008)

Did a quick google search and found a guide on how to clean sensors on the EOS series.

Clicky pdf

Just opened her up, used a blower bulb and [borat]great success[/borat].

Very relieved and v pleased. 

Thanks for the great advice


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## TCimages (Mar 6, 2008)

One really easy way to determine if you have dust on your sensor open a doc in PS or other application and fill it with white. Expand to fill the screen. Put your camera in the AV mode and open the aperture to well over 20. Set the focus mode to manual. Now with the camera a few inches from the screen take a picture of the white document. Slowly move the camera in small circles to ensure dust on your pc screen isn't picked up. 

One other thing, don't forget to check the lens for dirt, specifically the mount end. This can show up on your images as well. 

If the Rocket blower isn't enough and you need a cleaning solution check this info out. 

http://www.cleaningdigitalcameras.com/

and this is what I recommend for a cleaning solution (E2):
http://www.photosol.com/

Here is a link to a thread I created when I cleaned mine:
http://www.thephotoforum.com/forum/showthread.php?t=110545


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## akazoly (Mar 8, 2008)

I like Copper Hill products. I get the sensor brush and work good. 
Visible Dust products = Expensive + Big marketing (In my opinion Arctic butterfly is not better than sensor sweep).

So I recommend Copper Hill, Nicholas the copperhill manager is very serious.
To clean dust, try:

1: Rocket Blower
2: The brush
3: Photosol sensor swabs + Eclipse. Is pretty safe if used with care.


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## akazoly (Mar 8, 2008)

Using copper hill sensor brush:

Before:




After:




Every DSLR user need this brush, is incredible eficient! and don't affect Indium Tin Dioxid coated sensors!

Don't spend your money on expensive products like Arctic Butterfly. Copper Hill sell the best products on market and this is not an advertising. Im very happy because I own this brush.


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