According to artist Julio LeParc, a member of GRAV in Paris, our "first experiments with light were conducted in 1959: We place the light in small boxes which reproduced, multiplied and combined with the screens made of Plexiglas slates, prisms, squares and circle shapes, using a scale of 14 colours. Like in other experiments it is not about creating luminous paintings. The light is but a way to manifest some of my concerns, such apprehending the variation of the potential induced and to manifest it in one visual field. Many experiments were made from the handling of material and the differentiation of the issues.
I also wanted to work simultaneously using reflections; some Plexiglas slates 45%,fixed or mobile elements placed on each side.So the reflected shapes inter penetrated in their transparency and seems to float in space. In other experiments of the same series, some Plexiglas slates were placed in depth so the lateral pictures lightening up alternatively, and created some visual sequences of 8 situations. Many topics can be subjected to all those experimental boxes, combining and alternating them in different way.
Some other experiments with the light are drawn from the mobile elements originally destined inside boxes. On the base of reflections of light on a background through small Plexiglas or metal slates, a series of experiments combined the place of the source of light, the incidence of the suspended elements, the shapes of the background. This series led me to realize in 1962 an ensemble destined to a white room in darkness.
The ensemble was laid out in the middle of a room; the suspended elements received 4 rays of light and distributed their reflections horizontally, vertically and obliquely on the wall, the ceiling and the floor. In 1962, I did other experiments using a ray of artificial light; some of them consist to project a ray of light on a cylinder which reflected the ray and distorted it on a wooden white circle which was the bottom of the cylinder. The ray was then intercepted by mobile elements which fractioned it by different manners. The visual results on the white circle were a constant and imperceptible game of shadows and lights, which were previously set. The same principal of shaved light was used to other experiments.
At the same time I realized other experiments to visualize rays of light in the space. First I tried to suspend, inside those small transparent Plexiglas boxes, some particles with air; to be able to penetrate those boxes with ray in movement, but I finally used some water in small aquariums. The water coloured with fluorescent aniline, made the ray of light coming through, perfectly visible. From these experiments, I conceived a smoker’s room which walls pierced with small holes, made spout out the moving luminous rays, so the air from the room reduced from the smoke permitted the visualisation of all the rays penetrating in all directions.
[In order] to surprise the viewer, to place him in the centre of a phenomenon, to embody him with[in a] visual situation, some experiments were realized in the first Labyrinth our group [GRAV, Groupe de Recherche d'Art Visuel ] presented at the Biennale of Paris in 1963... Those experiments excluded the possibilities to apprehend the phenomenon with one look, like in the situation where traditional paintings hanged to a wall or sculpture on a stand where the viewer is turning around. On the contrary, they plunge [the viewer into] a visual situation…
Those experiments with light and movement are linked to the principal of moving away from a fix, stable and definite work. The viewer is surrounded with the development of a multitude of changes. The uniform support of the element or the forms, accentuates without distraction, the instability mode in evidence, so the viewer perceives a part of the changes which is enough to apprehend the total meaning of the experience.
In the traditional art work, everything is fixed by sign and keys one has to know to first be able to enjoy it. Facing this situation we thought, the presentation of experiments with multiple possibilities of change, from which the images were the results of the simple set up of elements more or less complex and not from an experimented hand, and where the artist represented a way limited but effective; starting or continuing the demolition of the traditional notions of Art and all its representation and appreciation."
 Text and images by Julio Le Parc, artist's website: http://julioleparc.org/en/artwork.php?aw_cat_id=7