YY_BitExtender

This plugin turns 8 bpc footage into 32 bpc footage, and lets you very easily tweak the results based on your needs.

To install it, simply drop the pbg file into your plugins folder, and start After Effects. (sorry CS3 users, but pixel bender plugins don't work with anything under CS4)

Find an image or video with some blown out parts, and some darker parts. Here's the one I used:

These are the parameters you are presented with:

Leave them as they are for now, and apply a filter that works in 32bpc to test it out. I used fast blur with a blurriness of 20:

So far, everything I've done could've been achieved with Andrew Kramers tutorial on 32 bpc, and Maltaannon's Bitweiser plugin. Next I'll explain the parameters, starting with Threshold:

Changing this value will determine how bright a pixel has to be before it is considered "superbright". Generally, you'll want to leave this at a very high value, such as 0.98. Setting it to 0.6 leads to the following result:

As you can see, with the threshold lower, the blobs of light become bigger.

The next parameter is Intensity. It determines how much brighter the "superbright" areas should be. Generally, leaving it at 1 is ok, though sometimes you want a more subtle effect. (sorry, no picture)

The parameter after that is Boost Color. This checkbox determines the method for drawing the superbright pixels. If checked (default), the superbright areas will be more saturated. This is what it would look like, unchecked:

The last parameter is the most interesting one, the Colorize parameter. If left white, it doesn't do anything, but if we change it to another color, say, green...

The superbright areas will have a green fringe:

This is a very useful feature if you have bright lights in a shot, and you would prefer to give the lights a color. It can also achieve some nice, stylistic effects.

Of course, this plugin doesn't only apply to the fast blur filter. It also applies to any other 32 bpc effect, motion blur, and more: