FR2657971A1 - Diffuser for macrophotography - Google Patents

Abstract

The invention relates to a diffuser for directing and diffusing light of a flash onto a small-size subject. This diffuser is mounted through the use of a filter holder on the front of an objective lens. It consists of a casing having, in its upper part, an orientable deflector (2), vertically in line with the latter a pyramid-shaped deflector composed of a front panel (3) and of two side panels (4a), (4b), parallel to these two panels and on either side of the latter two deflectors (6a) and (6b) and facing the latter two other deflectors (8a) and (8b), these deflectors are connected together by four reflectors (7a), (7b), (7c), (7d) and a rear face (1). All the elements have a coating which reflects the light onto their internal faces. A translucent flat diffuser supplements the diffuser by way of an accessory.

Description

 The present invention relates to a device for orienting and diffusing the light emitted by a flash in the context of shooting small objects and in particular photomacrographies.

 Photomacrography requires a significant amount of light, especially below the ratio of 0.5 times the life size, and this when you want to combine high depth of field (sharpness) and fast speed (without risk of moving).

 In addition, a magnification ratio of twice given for example requires nine times more light than a magnification ratio of 0.5 times the size.

For all these reasons, the use of a flash is useful, even essential
There are already ring flashes with several disadvantages:
- Very high cost of the flash at the purchase for the customers.

 - Usable only in photomacrography.

- Giving a flat light characteristic of this type of flash
The present invention as a new industrial product also makes it possible to overcome these various drawbacks.

 It proposes to make a device easily adaptable on many cameras through a filter holder placed on the front of the lens.

 It also uses the light source of a TTL flash (abbreviation of THROUGH T LENS means through obiective) or not, incorporated in a camera or fixed on the latter, along a lateral axis substantially equivalent to the axis of the goal.

 In addition, the present invention retains all the advantages of flash TTL.

 In the context of the use of a non-TTL flash, it will nevertheless be easy thanks to the various existing mathematical formulas for photomacrography and after some tests to obtain excellent results.

 The diffuser is characterized in that the tool comprises a housing body.

 The device is composed in a particular embodiment of an open monoblock case and in its upper part of a pivoting element.

 In a preferred embodiment the housing inserting the pivoting element may be composed of several inserts, assembled by nesting and then glued.

 All these elements will be made by molding plastic materials.

Other advantages and features of the invention will become apparent on reading the following description given by way of non-limiting example of a particular embodiment of the device of the invention with reference to the appended drawings in which
Figure i shows a perspective schematic diagram, the position of the deflector (2) being approximately 45.

 FIG. 2 represents a block diagram in left view, showing the path of the light according to the position of the deflector (2).

 Figure 3 shows an exploded perspective view showing the different parts of the device according to a particular method of manufacture.

 Figure 4 shows a front view.

 Figure 5 shows a left view and the diffuser accessory (20).

 Figure 6 shows a rear view.

 The device after assembly is characterized in that it comprises in its upper central part an opening (O) surmounted by a tilting panel (2) serving as deflector and extending projecting forwardly.

In a particular embodiment, the means provided for rotating and maintaining the deflector (2) in a given position can be realized.
- By two pins (9) at the rear of the deflector (2) which will pivot the latter in housing arranged for this purpose on the flanges (5a) and (5bof.

 - By two other tenons (10) of dimensions capable of sliding in notches (II) also fitted on these same flanges.

 All these tenons also having a spacer role.

 In a particular embodiment, the tenons (9) and (10) will be recessed in their center for the purpose of receiving inserts.

 Reinforcements (17) will advantageously be arranged around the sliding and pivoting zones, these being preferably on the outer faces.

 The limitation of the rotation of said deflector may be ensured in a particular embodiment by thinning (Figure 3: (15) of the flanges (5a) and (5b) on their inner faces in a given angular portion.

 Opposite with the deflector (2) and at a lower floor a pyramidal volume ((3) - (4a) - (4b) truncated to 1 t back, and consisting of a front panel (3) and two side panels ( 4a) and (4b).

 Parallel to the side panels and on both sides of these are two rectangular faces (6a) and (6b) laterally inclined.

 These also face two rectangular bottom panels (8a) and (8b) inclined forward.

 These different baffles are interconnected by four vertical trapezoidal side panels (7a>, (7b), (7c), (7d) thus forming the lower part of the device.

 According to one characteristic of the invention, the angles of inclination of these deflector panels (3), (4a), (4b), (6a), (6b), (8a), (8b), will be substantially equivalent to 45 with the exception of the baffle (2) top of the device having meanwhile a variable inclination of between 20 and 45.

 The rear face (1) for securing the assembly is characterized in that it connects the two concave volumes thus obtained only in its upper part.

 According to another characteristic, the extension of this rear face upwards will be slightly greater than the top of the half-pyramid.

 A recess is thus obtained giving two distinct lower parts.

 This recess extends under the half-pyramid in order to let the passage of the lens and the filter holder at the front of the device.

 In a particular embodiment, the adaptation means are characterized by the presence on the two lateral faces (7c) and (7b) situated under the half-pyramid of adaptation elements (12) of shapes and dimensions such that they are likely to fit a filter holder.

 It is obvious that the device can be adapted to receive different models of filter holder and the evolution thereof without departing from the scope or spirit of the invention.

According to one of the characteristics of the device and according to a particular embodiment, all the surfaces capable of returning or directing the light will undergo on their faces concerned a treatment allowing them to reflect this light namely, the surfaces of the panels facing each other as well as those associated with these. All forming the inside of said case
Such characteristics therefore allow the luminous flux to flow according to the description below
- A quantity of light coming from a flash placed behind the device will cross it without reflection thus giving a luminous atmosphere to the back of the subject.

- Another quantity of light will be returned by the deflector (2) according to three possibilities
1) Striking said deflector (2) in its protruding part, it will be reflected vertically above the latter causing a significant lighting zone of a few millimeters to about thirty centimeters in front of the lens, according to the inclination of the deflector (2) .

 2) Striking said baffle (2) back from its protruding part, it will be directed towards the baffle (3) and then directly returned to the subject to be photographed.

 3) Striking the deflector (2) back from its protruding part, it will follow the deflector network indicated as follows (2) - (4) - (6) - (8) - SUBJECT.

 The light thus reflected will give a side light contribution substantially reducing the black background effect.

 It is quite obvious that the faces (1), (5a), (5b), (7a), (7b), (7cl, (7d) participate in the luminous equilibrium. multiple illumination and at widely varying distances thanks to the adjustable deflector (2) whose position 45 "will be ideal for photomacrography of high amplitude and the position 20 will favor subjects between 20cm and 80cm, it is obvious that intermediate positions may also be used.

 In a particular embodiment, the faces constituting said box may have light stripped as well as rounded areas.

For the sake of improving the diffusion of light for certain difficult subjects, and according to a particular embodiment a translucent diffuser may be mounted by interlocking the latter at the front of the device
The translucent diffuser being characterized by the fact that its shape perfectly matches the front of said case.

 In a particular mode of manufacture the surface of this diffuser is composed of a multitude of facets.

 This accessory also allows evenly distributing the lighting, thus significantly reducing unwanted glare and shine.

 The body of the device according to the invention is made by molding a plastic material known as A.B.S .; the treatment ensuring the gloss of the different surfaces is obtained by vacuum metallization. On the flanges shown in Figure 3 an example of socket (14) adapted to adapt to the central portion.

 Holes (16) will contribute to the rigidity of the lateral parts of the device. On the model presented, given as examples of male metal inserts (18) and knurled buttons (19) will be an integral part of the device of the invention.

 However, it is obvious that the invention is not limited to the form shown and the materials and various treatments described by way of example.

Claims (8)

 1) Diffuser for directing and diffusing the light emitted by a flash of all types for shooting small objects and in particular photomacrographies comprising a housing body fitting through a filter holder on the front of a lens, diffuser characterized in that said housing comprises two lateral flanges (5a) and (5b) surmounted by an inclined deflector (2), facing the latter to a lower floor are, a pyramidal baffle consisting of a panel triangular front (3) and two lateral triangular panels (4a) and (4b); parallel to these two side panels and on both sides thereof two rectangular deflectors (6a) and (6b) being positioned laterally inclined and in line with the latter two other rectangular deflectors (8a) and (8b) being inclined forwardly, furthermore the various deflectors mentioned above being connected by four lateral reflectors of trapezoidal shape (7a), (7b), (7c), (7d) and a rear facade (1).  2) Diffuser according to claim 1, characterized in that the deflector (2) has elements (9), (10), (18), (19) on these lateral faces intended to rotate in housing (in ) {provided provided for this purpose on the flanges (5a) and (5b) and block it also in a given position.  3) Diffuser according to claim 2 characterized in that the deflector (2) has a projecting portion capable of returning a portion of the light at a more or less open angle depending on its position.  4) Diffuser according to any one of the preceding claims, characterized in that the angles of the deflectors (3), (4a), (4b), (6a), (6b), (8a), (8b) have a value between about 40 and 50., the deflector (2) having a pivotal latitude of between 20 and 45.  5) Diffuser according to any one of the preceding claims characterized in that the panels comprising said housing have on their inner faces a light reflective coating.  6> Diffuser according to any one of the preceding claims characterized in that said housing may include relief angles.  7) Diffuser according to any one of the preceding claims characterized in that it further comprises elements necessary for its adaptation to a filter holder, placed on the non-reflective faces of the side panels (7b) and (7c).  8) Diffuser according to any one of the preceding claims characterized in that it is reinforced by a translucent diffuser (2O) plane composed of multiple facets perfectly matching the front of said case.