Hace Sol

Alright, so many times when I've worked on a project it seems that there could always be some way to take the extra step to push the realism and excitement. So I came up with a nice way of creating a sun, and here's how it goes:

Start out by creating a new solid that is a sort of yellow/orange color like this:

Now select the oval mask shape tool, and while you drag you may choose to hold down shift to confine it to the shape of a circle. This is the basis for our sun. Next, apply a simple fast blur to around one to five pixels, depending on the resolution of the video behind it. Duplicate the layer twice. With the first duplicate, turn the blur amount to to about 50 pixels, and set the third one to anywhere between 150 and 200 pixels, judging which looks best. Now you can set the core of the sun to the screen transfer mode (the layer with the one-pixel blur), and the other two to the add transfer mode. And this is what we get:Of course you would want to motion track the sun into the sky, and set the anchor point to be the center of the sun, using the pan behind tool.

Now it looks better, but we can do something else, and that's a lens flare. Now after effects is quite limited in it's ability to create lens flares, since it only has three presets, so you may find yourself buying a plug-in eventually, such as Knoll Light Factory.

But if you opt to use the After Effects lens flare effect, create a new black solid, apply the lens flare effect (Effect-->Generate-->Lens Flare), adjust the settings to your preference, and set the layer to screen, not add (it ends up being way to bright, and blows out many parts of the flare). Be sure to paste the tracking data from the sun to the Flare Center. I always bring the opacity of the flare layer down as well.

After you've done all that, we have this:

Lastly, you can perform your color correction, and end up with something like this:
It's a very subtle effect, but realistic compositing and grading is all about the little details.

Note: You want to set the black and white points after adding the sun, but before the lens flare, as well as the gradients and vignettes. All of this was demonstrated in my tutorial, Creating Digital Cinema.