Method for producing a lens attachment for generating reflections

Abstract

Method for producing a lens attachment (1) for a camera lens for generating reflections (3), comprising the following steps:- providing a transparent disc (2);- providing a frame which closely surrounds the disc around its circumference and protrudes perpendicularly from the disc plane;- applying an adhesive layer (4) to the disc, wherein the adhesive layer cannot flow off due to the frame, but is distributed evenly over the disc;- introducing objects (5) into the adhesive layer;- removing air bubbles from the adhesive layer;- applying a transparent cover disc (6) so that the adhesive layer with the objects therein lies between the two discs; and- removing the frame.

Description

FIELD OF TECHNOLOGY

[0001] The present invention relates to a method for producing lens attachments for generating reflections, in particular in response to light sources in a photographed object. BACKGROUND AND STATE OF THE ART

[0002] Numerous lens attachments are known for influencing the image exposed on a photographic film. These attachments are placed either in front of a photographic lens or between the lens and the camera. There are filters for absorbing unwanted radiation, such as UV or skylight filters; filters for filtering out reflections, such as polarizers; filters for influencing color temperature; and filters for enhancing the contrast between specific color ranges of a photographic subject, such as yellow, red, and green filters in black-and-white photography. In cinematography, lens attachments are often used to create additional effects, such as soft-focus filters or so-called star effect filters. The latter usually feature engraved glass panes that create reflections if the subject being photographed contains highlights. Such star effect filters are mentioned, for example, in the catalog "CO-KIN Creative Filter System (July 2002)" on page 13 ff.However, they have several disadvantages - in particular, that due to the nature of glass engravings, they only produce reflections of the same color as the lights.

[0003] DE 20 50 652 A discloses an objective filter for generating diffraction patterns in optical images. For this purpose, multilayer strips of interference coatings are vapor-deposited onto a transparent filter holder. The purpose of this filter is to create a diffraction effect that occurs only for a specific color. This results in a sequence of images of a light source whose colors can be predetermined—in contrast to conventional wire diffraction gratings. Since the goal of DE 20 50 652 A is to limit diffraction to specific colors, a device with vapor-deposited interference coatings is required, which is not easily adaptable to different camera / lens equipment.

[0004] The applicant's EP 1 672 419 B1 discloses a lens attachment for generating reflections in response to light sources in an object to be photographed, comprising a frame that can be attached to a camera lens in a plane perpendicular to its optical axis and has a reflection device. The reflection device consists of threads or filaments that are stretched over the camera lens in the frame and generate reflections at right angles to their direction of extension. However, the possibilities regarding the geometric shapes that can be generated in the lens plane with the threads are limited: Since the threads are clamped in the frame, at best straight figures can be generated – curvatures are not possible.

[0005] DE 101 37 477 A1 discloses an optical camera filter for compensating stray light on foreground objects. The filter has several layers consisting of two optically pure glass or plastic panes with different colors and textures, and a plastic film with correction ink and embedded silver particles between them.

[0006] US Pat. No. 4,713,477 A discloses a filter that, in addition to filtering, also serves to generate electrical energy from the light absorbed by the filter. The filter comprises two glass panes and an adhesive layer between them. SUMMARY OF THE INVENTION

[0007] One object of the present invention is a lens attachment for generating reflections in response to light sources present in a photographed object, which overcomes the disadvantages of the prior art. The present invention is directed to a lens attachment that is more versatile and enables the generation of reflections that were previously unattainable. Furthermore, the lens attachment is simple to manufacture.

[0008] This can be achieved with a method for producing a lens attachment according to claim 1, wherein the method according to the invention comprises the following steps: providing a transparent pane; providing a frame which closely surrounds the pane around its circumference and protrudes perpendicularly from the plane of the pane; applying an adhesive layer to the pane, wherein the adhesive layer cannot flow off due to the frame but is distributed evenly over the pane; introducing objects into the adhesive layer; freeing the adhesive layer of air bubbles; applying a transparent cover pane so that the adhesive layer with the objects therein lies between the two panes; and removing the frame.

[0009] Other advantageous features of the method and the lens attachment are disclosed in subclaims 2-11. Character list Fig. 1 shows the general concept of the lens attachment according to the invention in an oblique view using a first embodiment; Fig. 2 shows a possible application of the lens attachment of the Fig. 1; Fig. 3a / b show the reflections caused by a light source in the first embodiment; Fig. Figure 4 shows some examples of reflections that are caused by a light source in a second embodiment: Fig. 5 shows, by way of example, some reflections produced by a light source in a third embodiment; and Fig. 6 shows, by way of example, some reflections which are caused by a light source in a fourth embodiment. DESCRIPTION OF THE PREFERRED EMBODIMENT

[0010] The Fig. 1 and Fig. 2 show the general structure and application of the lens attachment 1 according to the invention. It consists of two transparent discs 2, 6, between which there is an adhesive layer 4, into which objects 5 are inserted. The objects can be, for example, thin threads that are wound in a circle, as in Fig. 1 can be seen.

[0011] The discs 2, 6 can be made of glass, but plastics are also possible. For the adhesive layer, a UV-curing or silicone adhesive can be used, for example. In any case, it must be an adhesive with good optical properties in the sense that the image quality is not significantly impaired by the lens attachment. In this context, the thickness of the adhesive layer is also important: a thickness of 0.2 - 3 mm has proven suitable. The threads can be, for example, transparent nylon threads treated with a transparent blue lacquer. In addition to the Fig. 1 shown circular wound threads, other objects in other geometric shapes can also be used, such as glass, metal or plastic parts, which already have a certain geometric shape such as ovals or polygons or can be arranged in such a shape (see Fig. 5 and Fig. 6).

[0012] The lens attachment 1 according to the invention is manufactured as follows. First, a transparent disc 2 is placed on a horizontal base. Then, a frame (not shown) is arranged around the disc 2, tightly surrounding the disc and protruding upwards from the disc plane. The purpose of this frame is to allow an adhesive layer 4 to be applied to the disc 2, which does not run down the sides of the disc, but remains on the disc with a certain thickness. Subsequently, objects 5 - such as nylon threads - are introduced into the adhesive layer. After the objects have been introduced, the adhesive layer 4 is freed of any air bubbles - e.g. under vacuum - in order to minimize optical losses. The adhesive layer 4, with the objects 5 contained therein, is then sealed from the outside by providing it with a transparent cover disc 6 - which, for example,It is tilted to allow air to escape. Finally, the frame is removed.

[0013] In use, the lens attachment 1 is positioned in front of the lens 7 of the camera 8 in the plane perpendicular to the optical axis ( Fig. 2). In this way, the camera lens “looks” through the lens attachment provided with the objects 5 onto the imaged object 9 - in the case of the Fig. 2 a motor vehicle.

[0014] The Fig. 3a / b - 6 show the corresponding reflections caused by light sources 10 present in the imaged object. If the imaged object 9 contains light sources, as in the case of Fig. 2 For example, when car headlights are switched on, these light sources 10 generate reflections 3, which in the case of threads 5 are perpendicular to their direction of extension - Fig. 3a and Fig. 3b shows the corresponding reflections for the first embodiment, in which a circularly wound thread 5 has been introduced into the adhesive layer 4.

[0015] Fig. Figure 4 shows some examples of the reflections that arise in a second embodiment in which several circularly wound threads have been introduced into the adhesive layer.

[0016] Fig. 5 and Fig. 6 show some examples of the reflections that occur in a third and fourth embodiment, in which geometrically different objects are distributed in a disordered manner ( Fig. 5) or similar elongated objects in orderly lines ( Fig. 6) have been incorporated into the adhesive layer.

[0017] Since the objects 5 are arranged close to the camera lens, they are not shown on the film and are therefore in the Fig. 3a / b - 6 also not shown.

[0018] As already stated above with conventional star effect filters, reflections are created in response to lights present in the imaged object perpendicular to the direction of extension of the devices generating the reflections. In the case of the Fig. 1, Fig. 3a / b and 4, the devices producing the reflections 11 are the threads 5 wound into a circular shape. They produce horizontal reflections in the form of short lines (about 2 mm) at right angles to each thread 5. Furthermore, the threads 5 do not necessarily cover the lens surface completely, but can be arranged in desired areas of the same, so that the reflection effect only appears in these areas - in Fig. 3a / b and 4 show arrangements with only one wound thread and with many wound threads distributed over the entire area, respectively.

[0019] As can be seen, this lens attachment—in contrast to state-of-the-art attachments—is easy to manufacture and adapts to all kinds of requirements: On the one hand, threads can be used, which can be shaped into geometric shapes in a variety of ways by positioning them in an adhesive layer. On the other hand, for the first time, completely different objects than just threads can be used, which greatly expands the scope, since these objects can themselves exhibit certain geometric shapes. The lens attachment according to the invention is therefore extremely versatile and can be manufactured for different camera lenses and purposes.

[0020] The lens attachment according to the invention can be used on any digital or analogue photo, video or film camera.

[0021] It should be emphasized that the above-mentioned embodiments of the present invention are merely exemplary. Numerous alternatives lie within the scope of the invention, as defined in the appended claims. For example, the lens attachment 1 can also be arranged behind the lens 7, i.e., between the lens 7 and the camera 8. Furthermore, other and / or differently shaped objects than those specified in the above description can be incorporated into the adhesive layer.

Claims

[1] Method for producing a lens attachment (1) for a camera lens for generating reflections (3), comprising the following steps: - Providing a transparent pane (2); - providing a frame which tightly surrounds the pane around its periphery and protrudes perpendicularly from the plane of the pane; - applying an adhesive layer (4) to the pane, whereby the adhesive layer cannot flow off due to the frame, but is distributed evenly over the pane; - Inserting objects (5) into the adhesive layer; - Remove air bubbles from the adhesive layer; - applying a transparent cover plate (6) so that the adhesive layer with the objects contained therein lies between the two plates; and - Removing the frame. [2] Method according to claim 1, wherein the panes (2, 6) are made of glass. [3] Method according to claim 1 or 2, wherein the adhesive (4) is a UV-curing or a silicone adhesive. [4] Method according to one of the preceding claims, wherein the thickness of the adhesive layer (4) is 0.2 - 3 mm. [5] Method according to one of the preceding claims, wherein the adhesive layer (4) is freed of air bubbles under vacuum. [6] Method according to one of the preceding claims, wherein the cover plate (6) is tilted open to allow air to escape. [7] Method according to one of the preceding claims, wherein the objects (5) are transparent nylon threads. [8] Method according to claim 7, wherein the threads (5) are coated with blue transparent lacquer. [9] Method according to claim 7 or 8, wherein the threads (5) are arranged in a circle. [10] Method according to claim 7 or 8, wherein the threads (5) are arranged in geometric shapes such as ovals or polygons. [11] Method according to one of claims 1-6, wherein the objects (5) are glass, metal or plastic parts.

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