1.

Open your image in Photoshop.

2.

Create a new layer.

(either in the panel or ctr + Shift + N)

3.

Select that new layer & go to Layer>New Adjustment Layer> Gradient Map.

Once the Gradient Map is created in the layers panel, double click the gradient symbol.

A new Properties window will pop up.

Double click on the gradient.

4.

Click on the black to white gradient, then double click under the gradient to add a colour.

Select either black or white and repeat so they’re alternating (as shown).

5.

The gradient map will make the image look something like a zebra met with an acid trip.

This makes it easier to spot those little dust spots, most of which you can’t see when the image is in actual colour.

6.

Make sure you have the layers in the following order (from the top) Gradient map, empty layer & original layer. click on the empty layer then click on the ‘Spot Healing Brush’ (pictured)

When selected, locate the bar along the top left of Photoshop and make sure your softness is at around 50% (to change click on the circle on the left), content-aware is on and the ‘Sample all layers’ box is ticked.

Note: make sure “Sample all layers is ticked on”

7. 

Select the empty layer created earlier and heal away!

This is an example of what it usually looks like for me.

Once finished just hide the gradient map layer.

Note: to remove spots hidden by either the black or white bands simple go back into the gradient map & shift the black/white colours.