Repeat the blur/load/fill cycle until your rays are the desired length. You can run the last filter again choosing Filter > Radial Blur (the top menu item), this applies the last filter with its last previously used values. In the example (which is for a video) I repeated the cycle three times to achieve my look. Depending on the resolution of your composition you may need to run the combination more or less times.
On the blurred layer named Light 1, apply the Color Overlay layer style by choosing Layer > Layer Style > Color Overlay. Select the desired color and adjust opacity to taste. You should get a real-time preview of your work if the Preview box is checked. Click OK.
7.Composite it (optional).
If you want to key the image in a video application you will need to create an alpha channel to store the transparency of the glow:
Turn off the visibility icon for all layers that you don’t want included in the alpha channel. Then make a new (empty) layer and make sure it is selected.
Choose Merge Visible from the Layer’s palette submenu while holding down Option (Mac OS) or Alt (Windows). The resulting layer contains all of the merged elements while leaving the originals behind. Cmd + click (Mac OS) or Ctrl + click (Windows) this new layer’s thumbnail to load the selection, and then turn this layer’s visibility icon off.
Switch to the channel’s palette and click on the Save Selection as Channel icon at the bottom of the palette. Once the alpha channel is created, you can release the selection by choosing Select > Deselect.
In the Layers palette, turn the background layer on and fill it with the same color as your glow. This will ensure that you have clean edges in your alpha channel by avoiding any stray color data in the glowing areas.
Be sure that you have only one alpha channel in your document. Then choose File > Save As and save a copy of the file in a format your NLE system recognizes such as PICT or TARGA. Make certain that the Save Alpha Channels box is checked so the alpha channel will be embedded.
Read Part 2 click here