The spot that is circled in the picture is a
dust spot on my picture. The dust is actually
on my sensor.
it does not show on on every picture. Sometimes
it is a lot lighter and slightly grey and
sometimes it is very faded.
You will see the dust spots when you take
pictures with a small f-stop, f-11, f-16, f32.
if it is just a light piece of dust you can take
off the lens and use one of the bulb air blowers
to blow air inside of the camera to blow away
the dust.
CAUTION
Do not use the tin air blower.
Do not blow into your camera with your damp
breath.
Make sure that the blower that you use is clean
and not damp.
Clean your camera in a clean area with no dust
in the air.
If this does not work, get your camera serviced
by a professional. You may be able to clean it yourself but your sensor is delicate and easily damaged.