Do you have to shoot a scene outside at night and you only have a small lamp to illuminate everything? All you have to do is shoot multiple clips illuminating different points of the scene, and use Kdenlive to blend everything into one very bright movie.
One of the most common problems in cinematography is lighting. To have a good photograph you need a lot of funds, and in some cases these are unlikely even for medium budget productions. In the world of independent cinema, of course, this problem is even more felt. In particular, shooting scenes at night is always very difficult. Even in great films, some tricks are required to maximize the amount of light entering the camera. Kubrick made himself an adapter to mount on his camera a very fast lens that Zeiss had produced exclusively for NASA’s moon missions. Today, most of the directors of photography resort to the trick of emptying tankers of water in the place to be illuminated: if you notice, many of the scenes shot at night outdoors always have puddles or in any case a certain humidity of the asphalt, of the concrete, and steel. This is because, by correctly illuminating, the water reflects the light towards the camera and a much more “shimmering” scene is obtained instead of a dark mass with a single illuminated point. Another trick is to improve the video digitally, and that’s what we can do without spending anything, thanks to Kdenlive. The basic idea was born from HDR photographs, or from those made with “brush strokes of light”. Those who are used to photographing dark environments, such as caves, abandoned buildings, etc., know that it is quite easy to illuminate a large room with a single lamp simply by holding a very long exposure time and painting with a beam of light every point of the image while the shutter is open. Another version is that of HDR images, with high dynamic range. To achieve them, just produce several shots with different brightness, so that every part of the scene is well lit, not too much and not too little. This second method is the most precise, because then you can merge the photos automatically or manually by choosing the right exposure for each part of the image. And it’s the same thing we can do with videos: just fix your camera on a tripod, and then make several movies, all with the same shot but with different lighting. Just hold your lamp in your hand and move between shots, in order to adequately illuminate every part of your scene. We will then use Kdenlive to merge all the clips one above the other, adding the amount of light present in each movie, obtaining a unique shot in which everything is correctly illuminated. We can do it thanks to the way of misapplication Screen , which sums up the various bright components of the movies without increasing the background noise, and thanks to the Lighten mode. This superimposes only the part of a clip that is brighter than the rest over the other clips. This mode is useful in detail, to avoid that the shadows produced by strong light overlap with those produced by weaker lights in other clips, which would produce a blur of the image. As always, you can see the example video at the following address: https://www.youtube.com/watch?v=1JccPPiGmnc
Illuminate with different exposures
The advantage of this method is that it actually allows the sum of light, even by combining different exposures. It means that you can use fast and low ISO exposures for parts of the scene that are closest to the camera, and therefore you can see them better. Instead, for the background you can safely raise the ISO sensitivity, in order to obtain greater lighting. In this way, the noise is not noticeable too much, because it is relegated to the areas that, in the scene, are at the bottom, and maybe even a little out of focus. The use of a diffused light source helps not to overly complicate the overlap: too sharp edges would be easily noticed, while merging patches of diffused light the final image is perfectly homogeneous.
So many lights, so many clips
We import a clip into Kdenlive for each different scene lighting
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The first fusion of lights
We combine the first two clips into a single doubly bright image
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Every detail in its place
We add all the clips needed to illuminate even the details
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Light to the foreground subject
To merge the subject with the illuminated scene we have to take care of edges and brightness curves
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