Thu 10-Jan-13 10:43 AM | edited Thu 10-Jan-13 12:43 PM by mpage
Those images are after applying Auto Levels in Photoshop. Here is the before image prior to applying Auto Levels.
This is an artificial image. It is shot at close focus (out-of-focus), only one or two inches from the monitor. As you can see, only a few faint spots of dust are visible. But when you apply Auto Levels, you see everything that is on the sensor (see before image above).
I will need to shoot a blue sky to see if dust appears in real-world images. Since I work nights, and since it is winter here, I will need to wait awhile to get a change to shoot a blue sky. Attachment#1 (jpg file)