How to use Motion Blur in Photoshop
Photoshop’s Motion Blur filter can, sometimes, get you close to the effect achieved by using a ND filter
Neutral Density filters are great at extending exposure time and creating a sense of movement, but they are not always the most convenient kit to use in all circumstances.
So it’s good to know that Photoshop’s Motion Blur filter can, sometimes, get you close to the effect achieved by using a ND filter. Here’s how it works:
After duplicating your background layer, access the Motion Blur filter by going to Filter>Blur>Motion Blur.
Adjusting the Angle setting will, obviously, affect the angle of the ‘motion’ that you are going to blur. The Distance slider is effectively a means of controlling the strength of the effect.
Finally, create a layer mask and use Cmd/Ctrl+Backspace to fill the mask with black. Use the Brush tool (with white as the foreground colour) and paint the Motion Blur effect back in over the desired areas. Hitting the backslash key on your keyboard will apply a live mask to allow you to better see what you are doing.