Moodlight

This is quite a complicated filter to explain; in fact, it's probably easier to use than it is to explain! Ever looked at a photograph and wished that you could re-shoot it, but change the lighting to add a warmer colour to the shadows, or a cooler one to the highlights? Or maybe you'd just like to add some really vibrant coloured lighting to spice things up a little. Well, now you can - or at least, you can change the lighting effects on an image without having to re-shoot it.

Imagine that you have three off-camera lights; each light can be switched on or off, and its colour can be anything you want it to be. Each light can be targeted to affect only those parts of the image that are within a specified brightness range. So, for example, you could add a blue colouration to the shadow areas, and maybe a yellowish colouration to the highlights. You can even add a third colouration to the mid-tones if you want to. However, there's no rule that restricts the lights to shadows, mid-tones and highlights; you can target all three lights to the shadow areas, or the highlights, or anything in between.

Let's take a look at how you can control these virtual lights...

The upper half of the control area of the dialog is devoted to the controls for the virtual lights; the lower half contains controls that affect the way that the lighting effects are actually applied to the image. The controls have deliberately been kept simple by only showing the controls for a single light. At the left hand side of this area, though, is a column of round radio-buttons labelled 'Light 1', 'Light 2', and 'Light 3'. When 'Light 1' is selected, the other controls affect the first virtual light; when 'Light 2' is selected they control the second light, and so on. Also, alongside each radio button is a checkbox that switches the corresponding light on or off - the light is 'on' when the box is checked. By default, all three lights are on, but their colour is set to black, so no change is visible in the preview.
The actual lighting controls work like this:
Target brightness	This slider sets the image brightness level at which the light will be targeted, with shadows for the low values and highlights for the high values. If you change this slider, you should see the corresponding coloured light move to different areas of the image.   Note You can also set the target brightness for a light by moving the mouse cursor over the preview window and right-clicking; you should see the slider jump to the value corresponding to the brightness of the part of the image you clicked on. This is usually quicker and easier than using the slider, though the slider can be useful for fine-tuning.
Tolerance	This slider sets the range of brightness that will be affected by the light. Increasing the tolerance will cause the light to spread into wider areas.
Colour of light	Click on this button to invoke the colour selector dialog and select a colour for the light.
The remaining controls affect the way that the lighting effects are actually applied to the image, like this:
Subtle/Extreme	With the default setting of 'Subtle', the intensity of the light is reduced toward the extremes of the tolerance range, and the original brightness levels are preserved. If you select the 'Extreme' setting, the filter works much more aggressively, and the final result will look less realistic.
Original colour	When this slider is at maximum, the image's original colour carries through to the final result. As you reduce the value, though, less of the original colour is preserved; when the slider is set to zero, the image is reduced to monochrome with the only colour coming from the three virtual lights. This can look very arty!
Mistiness	Although the mechanisms mentioned under the 'Subtle/Extreme' control give a reasonably good result, at some settings the edges of coloured areas may be too pronounced. This slider allows you to apply a degree of smoothing to the effect, which will usually give a more natural-looking result. You can also use high settings to give a misty, surreal look to the image.
Aggression	Finally, this slider allows you to control the overall strength with which the effect is applied.

You can use this filter in a million ways... to improve the colouration in a sunset, to add atmosphere to a portrait... here are just a few 'before' and 'after' shots.
I added some orange to the darker areas of sky, and some yellow to the dark foreground to give a matching warmth.
Here, I just hit 'Random' a few times until I got something I liked. Not that this particular tree is especially likeable; my kids call it the 'scary tree', though it's looking better recently since the horribly pollarded branches have begun to grow again.
Let's face it: there's nothing anyone can do to improve upon the ethereal beauty of the divine Ms Sophie Marceau. Filter writers are powerless in the face of such charisma.