Kdenlive as GIMP: the video editing program includes incredibly powerful tools to correct the colors of the movies, treating them as if they were simple photographs. We will try to achieve the bleach bypass effect and the lomo effect.
Among the figures of great importance in the production of a film there is the color corrector. It is a profession still little known to the public, because it is relatively new. In fact, the possibility of adjusting colors in post production was born with digital cinema. Previously, in fact, the task was carried out by the director of photography. In fact, when working with film, a filter was applied to the camera lens to change the color rendering. If you have ever used super8 films, you will remember that Kodak colored positives were supplied with a rather precise indication on the packaging: the filter model to be used when shooting with tungsten lights. The films were in fact calibrated for sunlight, and if you wanted to use a lamp with a different color temperature, you had to affix a colored filter to the lens (many cameras had integrated it, and it could be applied by moving a lever). With digital images, of course, white balance correction can be done in postproduction, before or after editing. There is, however, something more: beyond the simple color balance, some special color effects can be created with the film, to give the image a different tone from what it would normally have. These effects were mainly achieved in the negative development phase. Perhaps the most famous example is the so-called bleach bypass. This effect consists of skipping the step of bleaching the colored negative (in the 6-step Kodak development process). The result is an image with a very high contrast and desaturated colors even if they have not completely disappeared. The effect is very popular because it lends drama to action or horror scenes. Another quite famous effect is the so-called “lomo”, which is very reminiscent of the amateur photographs of the 70s. In this case, the colors are very saturated and the image is bright enough, but has a vignetting on the edges. This is due to the fact that lomo images are always taken with a very wide-angle lens to be able to “seize the moment” without having to waste too much time framing the subject and focusing it. Even today, the lomo effect is very useful in movies to give the idea of a “family memory”, to provide a nostalgic or melancholy tone to a scene. Can these effects be simulated with digital movies? Of course, using Kdenlive and one of its most incredible features: the photo editing tools. Among the editing programs out there, Kdenlive is the most advanced not only among the free programs but also among the mid-range ones as regards color correction. In fact, it has tools that are very reminiscent of GIMP: we will use color curves, levels, and overlapping modes such as overlay and hardlight. Keep in mind that the lomo effect is better when shooting outdoors, on a very bright sunny day. Instead, the bleach bypass is better suited to low light conditions, such as the interior of a building, at night, or on a cloudy or even rainy day. As always, you can see the example video at the following address: https://www.youtube.com/watch?v=2T6Ch-4KKnQ
The unsharp mask
Lomo photographs had the characteristic of making the edges of the various objects very evident. To obtain this result digitally we can use a “unsharp mask”. Many editing programs offer a ready-to-use one, and until a few versions ago it was also present in Kdenlive (now temporarily removed due to conflicts with some dependencies). In our tutorial we explain, however, how to make a professional, fully configurable unsharp mask. This effect is important because it can also be useful in other cases: basically, wherever it is necessary to put the image “a little more in focus”. For example: if we film when there is a lot of humidity in the air, the images will be covered with a matte patina, slightly blurred. In this case, the unsharp mask will allow us to get a perfect movie. Of course, the “strength” of the unsharp mask depends on the effect Square blur : its kernel value should not be too low or too high.
One color track, the other in grayscale
We place the same clip in two overlapping tracks
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Without bleach
We perform the bleach bypass, that is the “lack of bleach”
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The curves of color in lomo style
We use the “curvature” tool to saturate the colors between highlights and shadows
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Unsharp and vignetting mask
We complete the lomo aspect of the image to remember the 70s films
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