This is a way to soften the lines around the light sources in your pictures, if you are working with light bulbs, lamps, etc.
I started with a picture of a string of light bulbs with some blur, but also pretty defined edges. I wanted to obscure those edges to stylize the light sources with more of a halo effect. I also avoided the ‘brush’ tool mentioned in “Blurring Sections of Pictures.”
1) Once your picture is in Photoshop, start by selecting the light sources. A quick way to do this is with the ‘Quick Selection Tool’ at the top left.
2) Create a new layer.
3) Copy your selected light sources and paste them into the new layer.
4) With this new layer selected, go to ‘Filter’ at the top, and then drop down to ‘Blur.’ You can scroll across to ‘Motion Blur’ or ‘Gaussian Blur’ or experiment with one of the many ‘Blur’ options.
5) This brings up the ‘Motion Blur’ menu box. You can control the angle of the blur, and the distance to which the pixels are being blurred. More distance equals more blur, so I kept this to 8 pixels which is plenty.
6) Click Okay. You can crop out the original light sources, but I actually prefer keeping the originals in the picture and viewing the new ones right on top the old.
7) The effect is non-destructive and you can repeat the steps to add more filters over top for greater effect. Here is an image with a layer of ‘Motion Blur’ and ‘Gaussian Blur.’
I think the effect makes the light sources dreamier and the lines less harsh than before. Of course, in these examples I made the differences subtle, but if you want a more dramatic effect you can repeat the process to make the light bulbs completely lose their definition and become orb like. Against a dark background it could make for a creepy effect.