Add a Fake Sun Using GIMP's Supernova Filter

Add a Fake Sun Using GIMP

This simple and brief tutorial shows you how you can use the Supernova filter in GIMP to add a fake sun to a photo. The effect is similar to the white flare that you get when shooting directly into the sun on a clear and bright day.

There are several reasons why you might want to use this effect; for instance, if you've got a photo that looks a little flat, this technique could be used to add some interest to the image. In this example, I'm using it to reduce the problem of the clouds being overexposed and the single spot of lens flare, which shows as a pale blue blob in the sky.

Open a Photo

For this effect to work best, you will need a photo from a bright sunny day, with at least a patch of clear blue sky, where the fake sun can be placed. As mentioned earlier, I'm using a photo with some burned out clouds and lens flare, which will hopefully be offset by this technique.

Go to File > Open and navigate to your photo, before clicking open.

Apply the Supernova Filter

The Supernova effect offers a very quick and easy way to place a fake sun in a photo.

Go to Filters > Light and Shadow > Supernova to open the dialog. Ensure that the Preview box is ticked and now you just need to click on the thumbnail to mark the center position of the sun. If the Show position box is ticked, cross hairs are displayed making placing the center more accurate. You can also specify the X and Y co-ordinates. If the Color is not set to white, click on it and set it to white. The Radius and Spokes settings can be adjusted as required. 100 spokes is an effective setting but you may want a smaller radius if a wide angle lens was used, while a larger radius may better suit a telephoto shot. You can ignore Random Hue.

Using Supernova Filter with a Color

If you want a more stylized effect, you can use a color in the Supernova settings.

In the image you will see that I set the Color to a sky blue color to roughly match the color of the sky in the photo. I also increased the Radius from 20 to 35 as using color in the Supernova filter visually reduces the size of the final result. I also increased the Spokes from 100 to 120, though this has little overall affect on the result. When this filter is applied, you can see that the rays from the fake sun are now more pronounced and this can be an effective tool for giving the suggestion of rays of light breaking through cloud. If you try the Random Hue slider now with a color set, you'll see an unnatural effect that you might quite like.