Making Objects Float with GIMP

A floating kitchen knife

A floating kitchen knife.

Making objects or people float in mid-air isn’t as hard as it seems. With a little planning and editing, we can produce a believable effect of floating or levitation.  We will create a floating knife in this tutorial. The principles you learn can also be applied to levitating a person or other objects. Lets begin.


Reduce camera shake

Camera on a tripod

Always use a tripod for sharp images.

When taking photographs of the object you wish to make to float, it is most important that everything stays absolutely still. Any movement or camera shake will later cause a huge headache in post production. This is the reason a tripod should be used when photographing your subject. Second, use a remote or a timer to shoot the photo. Do not manually press down on the shutter since this will cause vibrations. If your camera is capable of mirror lock up, take advantage of that feature to cut camera shake.

Make use of manual settings & manual focus

We need two images to create the effect of levitation. One image has the object in view while the other does not. That said, if you shoot both images with any other exposure mode other than manual, the camera’s sensors will detect the change of environment and adjust the exposure. This needs to be avoided. We want both images to be identical in position and in exposure. To accomplish this, the camera must be set to manual exposure and set the exposure for your image with the floating object in view. Also, manual focus must be used to keep the camera from refocusing when we take both pictures.

Setting up your subject

The idea of setting up your floating subject is simple. One picture has your object levitated by resting it on top of something, in my case two erasers, and another picture without the floating subject or object. When choosing an object to hold your subject up, try to use the smallest object possible. Using a smaller object as your pillar or stand will help you later in post production.

Taking the two photos

Two photographs must be taken as mentioned before. Setup the floating subject on top of the other objects in your composition. Manually set the focus and exposure. Take your first photograph. Take the floating subject, along with the objects used to hold it up, out of your composition. Shoot another photograph.

Two images, one with the floating object and the other without.

That concludes Setting Up & Taking the Photos section of this tutorial.


The layers dialog

Removing unwanted areas

Open GIMP on your computer and import both images into GIMP. The image with the knife, name it With Floating Object while the image without the knife, name it Without Floating Object.

The With Floating Object layer should be on top.

Click on the eye next to the layer to make it invisible or visible.

Create a duplicate of the With Floating Object layer. The name of the new layer is With Floating Object copy. We will use the With Floating Object copy layer later to create a shadow. For now, make this layer invisible by pressing the icon of an eye next to the layer.


Create a layer mask for the With Floating Object layer. You do that by right clicking on the With Floating Object layer and selecting Add Layer Mask from the drop down menu. Initialize Layer Mask to White.

Paint with a black brush the areas you want to remove from the image. Example, paint with a black brush the objects that are holding up the knife and all of the shadow from the knife.

Selection using the Free Select Tool

TIP: Use the Free Select Tool to guarantee a straight edge on your blade. Draw a line with the Free Select Tool along the edge of the knife and then around the shadow. Once done, select the Black Foreground color and slide it into the lasso you created. Press Shift+Ctrl+A to deselect everything, or select Select > None from the top toolbar.
Your image should now be free from any unwanted objects and shadows.

Drawing a shadow

Draw around the shadow with the Free Selection Tool.

We have successfully removed the stands that were holding the knife up and the knife’s shadow. Now we need to draw in our own shadow.

Make With Floating Object copy visible by clicking the space where the eye was before we made it invisible. Now use the Free Select Tool to draw an outline around the shadow. Once drawn, without deselecting, click on Create a new layer button. Accept the default values in the New Layer dialog box but make sure the layer fill type is set to Transparency. With the New Layer selected, slide the black color from the color palette into the outline you drew with the Free Select Tool.Press Shift+Ctrl+A to deselect and rename the New Layer layer to Shadow. Make a copy of the Shadow layer and remember to make the With Floating Object copy layer invisible again. 

Apply Gaussian Blur to the shadow copy layer

Now we will blur the shadow. Make the Shadow layer invisible since that’s just our backup incase we want to revert to the original. Select the Shadow copy layer and select Filter > Blur > Gaussian Blur from the toolbar. I will add 70 pixels to my horizontal and vertical blur radius. You may need to experiment to get the effect you are looking for in your image.



TOP: Selective blurring Bottom: Adjust transparency

In my image, the tip of blade casts a shadow over the edge of the cutting board. I have to make the tip of the shadow a little more blurry. I do this by selecting the tip area with the Free Select Tool and reapplying the Gaussian Blur filter.



Now we lower the transparency of the Shadow copy layer. In my image, the lightest area of the shadow is on the tip, so I will lower my transparency to match the intensity of the shadow in this area.

Duplicate the Shadow copy layer. This will darken the shadow as a whole, I need the tip of the shadow to be lighter than the rest of the knife’s shadow.Select Shadow copy#1 (the top most layer) and make a new layer mask. Initialize layer mask to white.With a black brush with it’s opacity set around 30, brush the areas of the shadow you want to lighten.Repeat the above steps to darken or lighten the shadow. 



When you are happy with your work, select Layer > New from Visible from the toolbar.

Now proceed to edit the image as you would normally would.
A floating kitchen knife

A floating kitchen knife.




3 responses to this post.

  1. […] picture were my rope lights behind me. I used this tutorial online to see how the process works- […]


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