Working with Light Leaks & Textures – GIMP

Three Old Buddies at the Poolside Images that are sharp and pristine are wonderful, but sometimes destroying an image can make a photograph more interesting.

In this GIMP tutorial, we will see how to use artificial light leaks and textures to degrade an image.

The Concept

This activity breaks down into two parts. First, we will take a look at making and applying light leaks followed by applying one or more textures.

Light Leaks

Example of a light leak from a film camera.

Light leaks in film cameras are caused by stray light entering into the housing of the camera where the film is stored. The stray light causes strange discoloration on the exposed film, usually strong yellow, red, blue and/or whites streaks will appear. Flickr group devoted to light leaks.

We will replicate light leaks by adding new layers with various colors, blurring this layer, and then applying a blending mode.

NOTE: As of this writing, GIMP has a bug where the Overlay and Soft Light blending modes have the same effect. GIMP has not fixed this issue because fixing it will break many scripts/plugins being used. To read more about this bug visit Hopefully the bug will be fixed in GIMP 2.8.


The application of textures to an image is extremely simple and straight forward. Images of textures are imported into GIMP and then a blend mode is used to blend the texture with the image.

You may find good quality and free textures at the following websites:

Also, you will find free textured brushes at the following websites:

Instructions to install brushes for GIMP.

Light Leak Methodology

The Sweeping Leak

The first thing we will do is to create the light leaks. Keep in mind, with your image you may need to play with the values to your liking. Lets get started.

Import your image into GIMP.

Choose the gradient

Blend Tool

Create a new transparent layer, name it Leak 1. We will use the Blend Tool (Press L) to create a gradient. We want to create a gradient the starts with yellow, fades into orange, and then fades into red and black. For this we can use the German flag smooth graduent. The German flag smooth gradient can be found on the Toolbox after the Blend Tool is selected.

Draw your gradient, into the Leak 1 layer. Then select Filters > Blur > Gaussian Blur from the tool bar. In the Gaussian Blur dialog box input a value into the Horizontal and Vertical blur radius. Try starting of with a 40px or 60px blur radius. You will have to try different values to achive the look you are aiming for. The reason we blur the light leak is to acquire a softer and more diffused effect. More over, you can paint the gradient at an angle to make an uneven leak wich looks more natural.


The German Flag Smooth gradient.

The above image shows the German Flag Smooth gradient applied to the Leak 1 layer. You will notice that parts of the gradient is transparent. I did this because I don’t want those parts of the gradients to show in my image. With the Eraser Tool with the opacity set around 30, I erased part of the gradient where I don’t want it to show.

Set the Leak 1 layer transparency to around 42 or so and the blend mode to Screen. You will notice that the image lights up in the area where there’s color, the yellow, the orange, and the red areas. Black does not affect the image at all with the Screen blend mode, that’s the reason we did not remove it from Leak 1.

With the above method, we created a light leak that spans across the image. Now we will learn how to place light leaks strategically in your photograph.

Strategic Leaks

Sometimes we want to hand select the position of the light leak and its shape. For this, we need to hand draw the leak onto a transparent layer.

Make a new transparent layer and name it Leak 2.

Using the Brush Tool, draw your new light leak onto the Leak 2 layer. In my case, I want to make a new and stronger light leak on the left hand side of the photo. The sweeping light leak was just not strong enough for my liking.

An orange and red leak

Select a color, preferably red, yellow, orange, or something of the like. After the light leak is drawn, apply Gaussian Blur to defuse the leak. In my example to the right, I drew a red leak then used Gaussian Blur and then drew and orange leak and applied Gaussian Blur once more.

For this light leak I will use the Soft Light blend mode because I want this leak to darken my image a bit. Then with the Opacity Slider, I will adjust the layer’s opacity to my liking.

That concludes the section on light leaks. Let us now move to textures.


Adding texture to your photography is very simple.

Import your texture file into GIMP and then choose how you would the texture and image to be blended. Experiment with the various blend modes for a different effect.

Note: If your texture file isn’t as big as your image, you can use the Scale Tool (Shift+T) to resize the texture.

Light leak and texture applied

I went ahead and added a texture to the image. As the blending modes, I chose Hard Light and I adjusted the Opacity Slider to my liking. I chose Hard Light because I wanted to keep the texture’s dark and light patches and overall sharpness. I also went ahead and used a layer mask to paint out the areas of the photograph along the bottom and sides to expose the texture even more.

I add a second texture in a new layer and changed the blending mode to Color because I wanted to mix the colors of the texture with the color of the photograph. I set the Opacity Slider to about 10.

Left: A colored texture. Right: The outcome after blending the texture on the left to the photo using Blending Mode: Color.

Textured Brushes

Collection of brushes on my computer

Just as there is two methods to add a light leak, what I call a sweeping light leak and a strategic light leak, there is also two methods to add texture to an image.

Brushes can be seen as strategic textures because you can place them anywhere on the image and as big or small as you like.

Just like the textures we applied before, textured brushes should be applied onto a new, transparent layer. The layer can then be blended, moved, resized, rotated, or easily removed.

This concludes the tutorial. If you have any questions or additional information you would like to share, please submit it through the comment box below. Also, if you haven’t already, follow us via Twitter.


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