Dirty CCD?

[Chazs]

Here's a photo (not a good one, but it does show the problem) I took a few weeks ago in Sweden.
http://members.isp01.net/snevetsc/photos/windmill.jpg
After playing around with several pictures, I've discovered several dark blobs. Obviously, they mostly show up in a solid color background. Here's a blowup:
http://members.isp01.net/snevetsc/photos/windmillclup.jpg

Is this a dirty CCD, and can it be safely cleaned?

Also, on another note. How does a dead pixel show up? Black dot, or white dot?

Thanks for your help.
CHUCK

[PacAce]

Not a dirty CCD but it is some kind of dust on your CMOS sensor. The easiest way to try to get rid of it without fraying your nerves or risking a heart attack is to go into the menu and select "Sensor cleaning" or something to that effect to lock up the mirror and open the shutter and then use a kingsize air blower (the bulb type) to blow the dust away. You should refer to your manual for more details. If you really stubborn dusts that just won't blow away, you can take the camera to a Canon service center for sensor cleaning or try it yourself using one of those kits they sell for cleaning sensors. People with weak hearts or unsteady hands should not try this at home. :)

Good luck.

[hmhm]

Is this a dirty CCD, and can it be safely cleaned?
How does a dead pixel show up? Black dot, or white dot?


Yes, that's what dust on the sensor looks like (the 1D has a CCD, all other Canon DSLRs have CMOS sensors).

Yes, the sensor can be cleaned. You can have it cleaned professionally, if you like, but since this is a maintenance operation that needs to be done periodically, you might want to just get used to doing it yourself.

I'd start with trying to blow off the dust either with a bulb blower (e.g. Giotto Rocket) or with some _clean_ compressed air, e.g. www.americanrecorder.com . Do _not_ use standard PC dust-off type products, they have propellant that can goo up the sensor. Do _not_ use the brush on a bulb blower.

If this doesn't work well enough, then you may need to swab the sensor. Look here for directions:
http://www.pbase.com/copperhill/ccd_cleaning


How does a dead pixel show up? Black dot, or white dot?


I've never seen a _dead_ pixel, though sometimes you come across "hot" pixels, i.e. a pixel that repeatably seems to display an inordinate amount of noise, particularly in long exposures. These will always show up as colored "speckles", never purely black or white, as each sensor photo site only measures one color, red, green, or blue. There are very "sharp", being individual pixels, they don't show up like blurry blobs, as in your photo, which is exactly what sensor dust looks like.
-harry

[Chazs]

Thanks guys. I'll head down and get a good cleaning kit this week, and give it a go. And give my heart a check-out too. :)

CHUCK

[Jim_T]

Here's a good site on sensor cleaning:

http://luminous-landscape.com/essays/sensor-cleaning.shtml

I've had my 10D for a year now.. I've had to wet clean the sensor twice.. I use the Pec-pad, Photosol method.. Most of the time I get by with a gentle puff from my bulb blower. Don't sweat the odd little speck, you can clone them out.. Usually you don't see dust until you start shooting with high f numbers.. (f/11 or higher).. Take a shot of the sky at f/22 then as wide as your lens will go.. Compare photos.. You'll see what I mean..

The sensor has a pretty tough glass filter over top of it. But if you decide to try your hand at cleaning... *be careful*.. A sensor replacement runs around $800.00 US

[NILOLIGIST]

I clean my camera using a air pump. I just pump air in it and it gets it clean and it stays clean for a good while too. I am not going to put anything inside of my camera trying to clean it. I will break it for sure.

Good luck,

NiL,

[Canuck]

I build model aircraft as well so I have an extremely low pressure air compressor that I have used successfully to get rid of the dust bunnies. I just attach the airgun to it and go to town so to speak.

[Belmondo]

I build model aircraft as well so I have an extremely low pressure air compressor that I have used successfully to get rid of the dust bunnies. I just attach the airgun to it and go to town so to speak.

Hopefully you're air is filtered. Even at low pressure with a highly focused stream of air, certain forms of airborne particulate matter could have sufficient velocity to do damage to good optics; I would imagine a sensor is also susceptible.

[Canuck]

I build model aircraft as well so I have an extremely low pressure air compressor that I have used successfully to get rid of the dust bunnies. I just attach the airgun to it and go to town so to speak.

Hopefully you're air is filtered. Even at low pressure with a highly focused stream of air, certain forms of airborne particulate matter could have sufficient velocity to do damage to good optics; I would imagine a sensor is also susceptible.

Ja about 5 psi.