Post Production: How To Make a Stop Motion Light Painting
It is possible to create a stop motion film using still photographs and light painting. Light painting uses very bright light points and longer exposure. Many times light painting is used with stop motion fights and other action. Light tends to be painted onto different photographs and then compiled into a stop motion video. This is a very fun and creative way to create a film.
Step 1. The Concept
Stop motion does not work on continuously shot film but works more on the principle of a flip book. Between each frame there is a slight movement and when all the frames are combined movement is found. Therefore it is possible to create a stop motion video using photographs and not film clips.
Step 2. Exposure
Stop motion needs a much longer exposure time than a traditional film. For each frame the exposure should be between 20 to 30 seconds. The exposure time can be extended further to as much as a minute. Be sure you are using a tripod otherwise the pictures will be blurry. Even the steadiest hand has issues with long exposure times. The vast majority of digital cameras will be able to set this custom exposure. Check in your camera manual on how to set the exposure time.
Step 3. Convert Image
The image for light painting needs to be dark so if the image is colored then it is necessary to convert it to a black and white image or darken the image. Some programs will have a black & white filter that can be used or you can change it using the channel mixer. It is important that the photo still maintains its details.
Step 4. Overlay Mask
It is necessary to create an overlay mask for the area you want to incorporate the light painting. Basically the overlay mask is used to darken the areas that will not be highlighted. To achieve this there needs to be a black fill layer underneath the overlay layer.
Step 5. Painting
It is on the overlay mask that it is possible to add the light painting. The brush for light painting should be completely opaque and not transparent at all. Once the light beams are in place it is possible to change the colors of the light. If you have multiple light beams that are different colors then multiple masks will be needed. Each mask will contain light that is a different color. When the mask has been painted on then merge everything together into one layer.
Step 6. Layering
With video editing software it is possible to take a light painting shot that was done on a wall and merge the light painting with a completely different background. So take light painting and put it in the middle of a beach at sunrise. This is not possible to do in real life because the beach would be too bright and there is nothing for the light to bounce off of. The techniques are the same used for mattes, masks and green screens. At minimum there will be the background layer and then the layer that contains the light painting.