D300 dust problem

spacegose · Jun 14, 2009

Hi

I own a D300 and have a little dust problem. Recently, I took some images with a very high aperture value (22 or higher) and I began noticing a little orb always appearing on the same spot in the image.

Sample image (spot marked with red circle):
http://www.aerion.ch/orb/_DSC4435.jpg

I googled the effect of dirt on a CCD but all the images I found were somehow different from mine. They all had small dark spots or hairs on the image. However, my pictures show a bright spot with a dark circle around it. Does anyone have an idea on what this could be or how I could remedy the problem? Any help is appreciated!

Christoph

kundalini · Jun 14, 2009

Is the spot all with the same lens? Have you seen it with other lenses? Could be the lens.

I'm sure you have gone through the in-camera sensor cleaner.

Apart from actually cleaning the sensor by hand, I would have something like a Giottos Blower on hand to remove dust/dirt.

spacegose · Jun 14, 2009

Sadly, I currently only have one lens... and yes, I've done the in-camera sensor cleaner several times.
Isn't the fact that the spot vanishes above f/8 (f/8 to f/2) very suspicious regarding dust on the sensor? Could this also be caused by dust in the lens? Is it possible to send the lens in for a thorough cleaning? How much would that cost?

Garbz · Jun 14, 2009

That looks like a wet spot, not a dust spot, and you have a second top right of the frame. Have you cleaned the lens before? Looks like a tiny drop of something dried on the sensor.

Dust is very dark, light won't pass through it. Water has a telltale black ring with a bright white spot in the centre, and this is a dried water mark where the residue is refracting light on the sensor.

It should be visible against light when looking at your sensor, probably only just though. The only real option for removal of this is a wet clean of the sensor. There are plenty of kits available and I'm sure someone here can recommend something.