Dark dots on my pictures, sensor cleaning?

[NadavCo]

Hello all,

I'm using Nikon D40x with a 18-135 lens and a polarize filter.
Some of my pictures contain small black dots in a static location.
The thing is, that it does not happens in all of my pictures,
I thinks it happens mostly when there is a powerful light source.
Here are a couple of examples:



Can you tell if it's a sensor cleaning issue?
If not, what else could it be?

Thanks,
Nadav

 

[480sparky41 40]

Time to clean the sensor!

 

[KmH]

Sensor dust is most visible in photos when a small lens aperture is used to make the photo.

A light colored background also contributes to the dust particle visibility, which is why dust spots are most often seen in sky or on a wall.

Image editing software, like Photoshop, usually has a Spot Healing tool.

 

[NadavCo]

Thanks guys!
I will definitely go and clean my sensor!