In this tutorial, which also has a video version, I’ll show you a technique often used in the wedding industry to enhance large or distinct light sources in your images and create a more elegant, immersive or “dreamy” environment around your subject. By allowing lights to pour in to your image, you are softening the feel of the overall composition while changing the mood of the piece.
I’ll begin by opening my image into GIMP by going to File>Open (pictured above) and selecting the file I want to open on my computer. Next, I’ll resize my image so that it is easier to work with. If you aren’t sure what size you want your final image is, I recommend figuring out where you intend to use the final image and what the recommended sizes are for that location. Then, resize your image to the largest size it needs to be. The reason we scale images down is because larger file sizes can slow down the software or your computer and make it slower or more frustrating to work with.
To scale, or re-size, my image, I’ll go to Image>Scale Image (pictured above) and choose the dimensions I want my image to be (pictured below).
I’ll then click “Scale” to apply the changes.
My image will have shrunk within the viewing window after the changes are applied. To zoom in on the image, I’ll grab the zoom tool by pressing the “Z” key on my keyboard and will click to zoom in on the image. If I zoom in too far, I can hold the Ctrl key while I click to zoom out.
Now that I have the image at the ideal viewing size within the viewing window, I’ll go over to my layers panel on the right side of the GIMP editor and select the main layer my image is on. I will duplicate this layer by clicking the “duplicate” icon (pictured above). You can double click the name of the layer to change the name. I will change it to “Photo Blur” as we will be blurring this layer.
With the new “Photo Blur” layer selected, go to Filters>Blur>Gaussian Blur (pictured above).
A dialogue box will appear where you can adjust the blur settings (pictured above). I am going to apply a Blur Radius of 50 to the horizontal and vertical settings. I will keep the Blur Method set to RLE. You can adjust these settings up or down on your own by clicking the up or down arrows until you get the amount of blur you would like. The blur is going to determine how “soft” the vignette around the image will look in our final product (as you’ll see in a moment). You can also click and drag on the preview window to reposition the preview and see how your applied blur appears. Click OK to apply the changes.
Next, I am going to add transparency information to the Photo Blur layer, which means when we attempt to erase parts of this layer, it will show the layer below rather than a background color (i.e. white). To do this, I’ll right click on the Photo Blur layer, then will click “Add Alpha Channel.” This will apply transparency to the layer.
Next, we are going to grab the ellipse select tool and draw an ellipse over our layer. Type “E” on your keyboard or go over to the Tools panel and click the ellipse select tool. Then, check “feather edges” in the left toolbar under the Tool Options section and drag the Radius bar to about 75 (pictured above). This will blur the line around the edge of our ellipse
With the tool selected, click and drag your mouse over the image. This will draw the ellipse over the layer. You can then hover your mouse over the outer edges of the ellipse until a rectangle appears, and can click and drag these rectangular areas to adjust the size of the ellipse (pictured above).
You’ll want the ellipse to overlap the boundaries of your image.
Once you have your ellipse placed where you want it, grab the eraser tool and erase the area inside of the ellipse (pictured above). You can use the left (“[“) or right (“]”) bracket keys to increase or decrease the size of your eraser brush. Or, simply drag the “size” bar found in the left toolbar to increase or decrease the size.
Begin erasing the area within the ellipse until all the blurred areas are gone. Next, go to Select>None to deselect the ellipse area (pictured above).
Next, click on the main image layer again in the right Layers panel. Grab the Color Select tool by holding Shift+O on your keyboard or by clicking the tool in the Tools panel. Click somewhere where there is a lot of light on the image, which will then select all the similar colors to that light source in your image (in this case, I clicked on a white light source, which then selected all the white in the image) – pictured above.
If you want to select more or less of the color of the light in your image, you can adjust the threshold (pictured above) to control how discriminately the color is selected prior to clicking on the color.
Next, hit Ctrl+C on your keyboard to copy the selected area, then hit Ctrl+V to paste the layer as its own floating layer. Click on the floating layer, then click the “Create a new layer” icon to anchor the floating layer to its own layer (pictured above). You can then double click on the layer name to change it – I’ll change mine to “Light Source.”
Click and drag the new light source layer (in the Layers panel) so that it is below the Photo blur layer (pictured above).
Next, with the Light Source layer still selected, go to Filters>Blur>Gaussian Blur. Turn up the blur until you have the desired amount – I will turn mine up to 85 – then click OK to apply the changes.
The image will now have a much softer glow throughout, giving us our desired effect, especially when combined with the blurred vignette we created earlier. You can increase or decrease the amount of opacity of the Light Source layer to adjust the strength of the effect.
That’s it for this tutorial!