Is it really digital noise?

[jojo]

I bought the 10D just over a year ago. From the very first outing with the camera, I noticed some dark circles on some my pictures - particularly in areas with light colors such as skies, skin, light-colored walls, etc. When I shoot several frames of the same subject, the circles appear in exactly the same place in every frame, and they are always round. I called Canon and they had me run the cleaning utility. When that didn't solve the problem, the declared that the problem was digital noise and refused to do anything else about it. In fact, they refused to even let me email a couple of photos so they could see if it really was digital noise.

Although I've read many internet posts about "digital noise" I haven't found any photos that illustrate exactly what digital noise looks like. I'm suspicious that what I have is actually a faulty camera. I frequently have to use Photoshop's clone tool to cover up these circles, and it's starting to get a little old. Can anyone suggest a website that does a good job of showing exactly what digital noise looks like?

[DocFrankenstein]

Can you post a few pic as an example of your "noise"?

[Jim_T]

I doubt very much that it's noise.. It sounds like dust to me. Did you send Canon a sample image ? I can't see them calling dark circles that are always in the same spot noise... Which Canon facility is telling you this ?

How did you "run the cleaning utility" ?? Can you post a sample image ?

Try shooting the sky at a high f number.. (Like f/22). If the dark spots get worse, then it is dust for sure. You may have to wet swab the sensor.. If you don't want to do that, you'll have to send the camera in.

[jojo]

I'll try posting a few sample pics. I wondered from the beginning if it was a dust problem, but since I put the lens on and then started shooting, I was tempted to dismiss that possibility since I had not done a lot of lens changing. For the first two, I tried to reduce the file sizes to make these more managable for posting, and I drew circles around the spots I was trying to describe.

On the last one, I left the file in its original size since it showed several of the circles with varying degrees of darkness. Also, on the last image, some of spots are not visible when Netscape initially loads the image, but if I click on the image to expand it to full size they are visible.

I'm not sure which Canon facility I was speaking with. When I spoke with Canon, I called an 800 support line I saw listed on the website. I specifically asked them if I could email some sample pics, but the support rep told me they couldn't accept pictures to examine. I though that was pretty strange, but at that point it seemed I had exhausted my options.

As for the cleaning, Canon told me to run Sensor Clean from the menu.

http://ocean68.homestead.com/files/images/canon/sample1.jpg
http://ocean68.homestead.com/files/images/canon/sample2.jpg
http://ocean68.homestead.com/files/images/canon/sample3.jpg

[timmyquest]

That aint noise, that looks like dust.

Clean your CMOS.

[jojo]

At Canon's suggestion, I tried selecting the Sensor Clean menu option then using a blower to clean the image sensor. Is that what you mean by cleaning the CMOS? If so, then I have already tried that a few times, and the problem didn't go away.

[hmhm]

At Canon's suggestion, I tried selecting the Sensor Clean menu option then using a blower to clean the image sensor. Is that what you mean by cleaning the CMOS? If so, then I have already tried that a few times, and the problem didn't go away.

It's dust/dirt.

Canon will instruct you to use the method that is least likely to result in a warranty return. :)

You can eliminate some dust using a blower, though you need a really big blower like a Giottos rocket, those dinky little ones with the little brush on the end don't do much. Or you can use _clean_ compressed air, like www.americanrecorder.com (don't use "dust off" products, they're goopy).

Sometimes compressed air won't work, and you need to "swab" the sensor with cleaning fluid, as described here:
http://www.pbase.com/copperhill/ccd_cleaning

If you want to see what digital noise looks like, set the camera to ISO 3200 and take a picture of something. It looks like a random, speckly, "staticy" (as in TV), overlay on top of the image.
-harry

[who10]

I agree with the Copperhill suggestion...

I had dust specks like yours on both a D60 and 10D - sensorswipe with Eclipse did the trick -- follow copperhill's instructions to the letter and you should be fine - or you can always send it into Canon for cleaning.


David

[Stapler123]

I'm glad i'm not you , i woul have just assumed they were ufo's and locked myself in a closet.

[jojo]

Thanks for all the replies, and thanks, Harry, for the copperhill suggestion! It looks like that's the way to go. It may take a couple of weeks to get my nerve up for that one, but I'm glad to know it's probably just a common dust problem rather than something wrong with the camera itself.

[CyberDyneSystems]

The CMOS cleaning task is a scary one.. but many seem to have had good luck.

I've had a DSLR for well over a year now and have yet to get up the nerve!
But.. now both Cameras have squeaky clean CMOS sensors.. and I intend to keep them that way.. so I need to invest in a spatula soon!