RU2319188C2 - Method and device for panoramic photography - Google Patents

Abstract

FIELD: panoramic photography.

SUBSTANCE: in accordance to the panoramic photography method, photography is performed when camera with objective are positioned in such a way, that condition is fulfilled for rotation of optical system around the nodal point, positioned on the main axis of objective and located inside the system of lenses, condition is fulfilled for constancy of angle of inclination and constancy of camera rotation angle, and condition is fulfilled for preservation of position of nodal point of objective relatively to the point of photography. Objective holder which has rods, positioned on horizontal axis and perpendicularly to objective axis, attached to it, is fastened on the camera with objective. To the ends of rods, threads and load are connected in such a way, that the system represents a double-thread plumb line. The camera with objective is fastened in such a way, that the axis of rods passes through nodal point, and for positioning the camera around the horizontal axis, liquid bubble level is used, which is fastened by means of a washer rotating around horizontal axis on one of the rods. Camera inclination angle is determined according to marks, applied to washer scale, and relatively to the indicator in rigid connection with the rod. To produce images of spherical panorama, onto the surface, where cameraman is standing, a template is placed with marked plumb line positioning point, after that the template is removed, and the point is used to position the plumb line, and photography is performed. Also, neck tripod is used, with a support on trousers belt of one side and small spherical head on the other end of the tripod, where the head is attached on the bottom of objective holder, and to the ends of the support ends of belt are connected, which belt is hanged on the users neck during photography. The plumb line contains an indicator, which is made collapsible, where one position of plumb line indicator is the transportation position, and the other one is the working position. On one of the rods a thick washer which rotates around horizontal axis is fastened, to which one of the double-thread plumb line is fastened, where on one side of the washer a scale is plotted, and scale indicator is rigidly connected to the belt. On one of the rods the liquid bubble level is held by means of the thick washer which rotates around the horizontal axis.

EFFECT: increased quality of images.

2 cl, 15 dwg

Description

The invention relates to devices for panoramic photography.

The most important factors for performing quality photography are:

1. The rotation of the optical system around a nodal point located on the main axis of the lens and located inside the lens system. This eliminates the parallax phenomenon, which greatly complicates the assembly of the original images into the resulting, and sometimes even excludes the possibility of such.

2. The constancy of the angle of the camera and the constancy of the angle of rotation, as well as the preservation of the planes of rotation. This is necessary for stable overlapping of adjacent images in a series. Both on the vertical side of the frame when shooting in one row, and overlapping on the horizontal sides of the frame in multi-row shooting.

3. Saving the position of the lens nodal point relative to the shooting point. Currently, for this type of photography, special panoramic heads are used. The design of such devices is the same. The camera is mounted on a bracket with the possibility of rotation in one or two planes. Moreover, the rotation is made along the axes passing through the nodal point. The camera position is either adjustable, or the design is designed for specific models of camera equipment. Turning angles are tracked along a limb or in more expensive models, rigid fixation of turns is used. This method produces a series of images without manifesting the parallax effect and stable overlap, also oriented strictly vertically. Strict vertical orientation, as a rule, is not required, because modern software, such as the free Panorama Tools package developed by Dr. Helmut Dresh.

Such devices are quite expensive and are used mainly by professional photographers. The use of such panoramic heads requires the installation of a tripod, which is not always convenient, as, for example, in sequential shooting or amateur shooting on vacation. As a result, despite the growing passion for panoramic photography, the use of such heads is not a mass phenomenon.

There is another way of panoramic photography - the use of a plumb line mounted on the lens. But this method has a number of disadvantages that are critical. The first of them is that the nodal point is inside the lens, and the plumb line is mounted on the outside, when tilting the camera it is impossible to determine the true position of the nodal point. The second drawback: it is impossible to maintain the vertical position of the camera and, as a result, it is impossible to ensure normal overlap between images when assembling a panorama. For this purpose, a liquid level is attached to the camera, but this cannot ensure the constancy of the angle of inclination with a multi-row panorama, because the level is fixed in one position. It is also impossible to provide stable overlap on the vertical side of the frame. Photographers try to provide overlapping eyes when shooting a series of frames. As a result, photography requires incredible stress and often misses later when the material is already shot. It is possible to shoot a series of images intended for assembling a spherical panorama only with high voltage and low quality, because it is impossible to control the overlap, slopes and accurately position the nodal point.

The objective of the invention is to provide a method and device for photographing a series of images intended for the assembly of panoramas, free from the disadvantages described above and used in practice of devices. In addition, the simplicity of the method and device allows it to be reproduced at home or to sell industrial products at an extremely low price, giving many lovers the opportunity to join this type of art. Light weight and compactness allow you to take this device for a walk or a business trip, as well as use in places where shooting with a tripod is difficult. In this case, with the inventive device, high-quality operational panoramic photography is possible.

This task is achieved by the fact that the plumb method with two threads that form a triangle and make it easy to orient the camera in a three-dimensional coordinate system is used at the heart of the method and the device based on it.

This plumb system is shown in figure 1.

Consider a rigid rod AB, in a three-dimensional coordinate system with a start at point O and axes X, Y, Z. The ends of the rod at points A and B are attached to the thread and weight. The system is a double-thread plumb. Moreover, the plumb is fixed as shown in Fig.1. Under the condition AA '= BB', the segment AB will be parallel to the segment A'B '.

If you attach a thread to the rod AB at the point N (AN = NB), then the rod AB will always be in the plane parallel to the OXY plane.

When the segment AB deviates from the horizontal, the increased tension of one of the threads returns the system to its original state.

When AB rotates around the Z axis, the plumb line will also rotate around this axis.

Moreover, the rotation angles of the segments AB and A'B 'will be identical.

By orienting the segment AB so that the plumb line is above point O, you can uniquely determine the position of point N in the three-dimensional coordinate system OXYZ. Let's complicate the task - suppose that a material body is fixed at point N. To accurately determine the position of this material body in a three-dimensional coordinate system, it will be necessary to determine the rotation angle along the Z and Y axes. As mentioned above, a two-strand plumb fixes a rotation around the X axis, blocking one degree of freedom of rotation. Thus, holding the plumb line over point O and tracking the angles of rotation around the axes Z and Y, we can uniquely determine the position in three-dimensional space of a material body fixed at point N.

Based on this method, a device is implemented, the design of which is shown in figure 2.

A lens holder (3) with rigidly attached rods (4) is attached to the camera (1) with the lens (2) in the region of the nodal point N. Threads of equal length (5) are attached to the ends of the rods. A plumb line (6) is attached to the threads on the opposite side. The threads are fixed to the plumb line not at one point, but at a small elongation, as shown in figure 2, according to the theoretical justifications given above.

The rods (4), threads (5) and holes (7) in the plumb line (4) form a trapezoid, since the nodal point N is on the line of attachment of the rods and exactly in the middle of the segment AB (the latter condition is easily realized due to the symmetrical design of all lenses ) Based on this, by positioning the plumb line at point O, we can uniquely fix the position of the nodal point N in space.

The base A'B 'of the trapezoid ABA'B' will always be parallel to the line of AB rods (4). This allows, having mounted a washer (8) with a bubble level (9) and a pointer (10) on a plumb line, with sufficient accuracy to track the rotation of the camera around the NO axis.

To position the camera around the horizontal axis AB, a liquid bubble level (9) is used, mounted on one of the rods. The basis for fastening is a rotating thick washer (8), mounted on one of the rods (4) so that it can be rotated around the axis AB. A scale is marked on one side of this washer. According to the marks on this scale, the angle of the camera is determined and the count is made relative to the pointer (10), rigidly connected with the rod.

Holding the camera at point M, it is easy to position the tilt of the camera relative to the horizon. When tilting the camera, the tension of one thread increases, and the other loosens.

As a result, the tension force of one of the threads T is trying to return the segment AB to a horizontal position, as shown in Fig.3.

As an optimal option - changes in the design of the lens in an industrial environment. By placing the mounts for the rods on the lens body, the manufacturer will significantly expand the possibilities of using its product.

The essence of the method of conducting a series of images intended for the assembly of panoramas is as follows.

The device on the camera lens is fixed so that the axis of the rods (4) passes through the nodal point. A template with a marked plumb point is placed on the surface where the photographer is standing. It is advisable to note in advance the place on the surface where it will be located, this point. This is required if a series of images is intended to create a spherical panorama. Having removed the template, a plumb line is positioned at this point and shooting is performed. The use of thin kapron threads makes it easy to retouch the picture and get rid of the image of threads and plumb in the frame. On hard surfaces it is best to use a flexible template that is easy to fold for transport. When shooting on grass and other similar surfaces, it is better to use a solid template made of plastic, wood, metal or other materials.

Using the inventive device, you can take pictures while standing in the water. For these purposes, a weighted template of material sinking in water is required.

By shortening the threads, you can take pictures at a short distance above the table or other elevation, which greatly expands the creative possibilities of the photographer.

Marks are marked on the template, allowing you to control the rotation of the camera around the vertical axis. Graduation is performed for the required overlapping frames. If multiple lenses or a zoom lens are used, then multiple scales are applied. In this case, for convenience, it is better to make colored scales or use several templates. For convenience, the marks are numbered. In this case, it is very simple to obtain the necessary sequence of images. Also, before starting photography, it is necessary to calibrate the scale on the drum (8). Calibration is best done in advance using a tripod. In multi-row shooting, the angle of overlapping images between the rows is taken into account. To do this, the camera is rigidly mounted at the required angle, and the rotating drum is oriented so that the bubble of the level (9) takes the marked position, and a mark is placed opposite the pointer (10) according to the angle of the camera. If you use multiple lenses with different focal lengths or a lens with a variable focal length, you will need to use several scales, if there are many, then you can use interchangeable scales.

The shooting is as follows. Holding the camera so that the main force is applied to point M, the camera’s position is slightly adjusted with the other hand. In this case, the plumb line system sets the camera in a vertical position. Typically, shooting images for assembling panoramas is performed in the "portrait" position, it is in this position that the camera is shown in Fig.2.

To use the camera in the “landscape” position, we orient the plumb line at point O. Then, the plumb line pointer (11) is oriented to the starting point of shooting and the camera is tilted according to the scale on the rotating drum (8). For this, the pointer of the drum (10) is set to the angle mark for the desired row. The tilt of the camera changes so that the bubble takes the marked position. The camera is mounted at the desired angle of inclination in the horizontal plane of rotation. Before pressing the camera shutter button, the position of the plumb line (6) and the plumb line indicator (11) are once again checked. Then shooting is done.

It is important to note that when using this device, there is no need to control framing by the viewfinder (as in a system with a single-plumb line), and it becomes possible to focus on turning marks, the height of the photo point and the level of horizontal tilt. In multi-row shooting, having completed the rotation cycle around the vertical axis, the washer (8) is transferred to the next mark and the series of photographing around the vertical axis is repeated.

This device makes it easy to take pictures of nadir and zenith. The shooting process in these positions is shown in Fig.4. The arrows indicate the direction of photography. The double-thread plumb design allows you to conveniently orient the camera at an angle of rotation around the axis AB.

The ability to take pictures of the surface on which the photographer stands, with a minimum of artifacts in the frame (thin threads and the upper part of the load) allows you to use this device in conjunction with a panoramic head for photographing the lower part of the sphere. Parts of the sphere, with the exception of the lower part, are removed using a tripod and a panoramic head, position I in FIG. 5. But the tripod does not allow you to remove the bottom. The legs of the tripod will be visible in the frame. Using a plumb line or in another way, the height h is measured - the distance from the nodal point to the surface. Moreover, for shooting in position II, the plumb line of the device must be of such a length that the distance from the nodal point to the surface is, as in case I, equal to h.

In position I, a point is marked under the tripod, say O, when the tripod is removed, a plumb line is set at the same point O for shooting in position II. As a result, the nodal point of the camera will be at the same point in space as in the case of shooting in position I.

An example of a panorama actually assembled is shown in FIG. 6.

In the field of the frame, the threads break off, since their ends are blocked by other images.

In such a simple way, it was impossible to accurately take a picture of the lower part of the spherical panorama.

To test and verify the technical capabilities of this device, a prototype pilot was made. A general view of the assembled device is shown in Fig.7.

To make a prototype of this device, two halves of the pipe holder were used. Rubber gasket protects the lens from damage and fixes the device perfectly. The distance between the points of attachment of the plumb lines in this sample was 250 mm. In the experiments, a Canon 10D camera with a ZENITAR-16M lens was used. The weight of the camera with a lens is about 1 kilogram. The used plumb load was 600 grams. This made it possible to easily hold the rods in a horizontal position. With a smaller weight of the camera, weights of less weight can be used.

A plexiglass washer (thickness 10 mm), turned with a household electric drill with a sharpened edge, into which a liquid bubble level was fixed using hot-melt adhesive, was used as a camera angle sensor. Pointers for determining the angles of inclination and rotation of the camera were made of ordinary wire. It should be noted that for practical use, the plumb index (11) (Fig. 2) is best made folding, as shown in Fig. 8.

One position of the plumb indicator will be in the transport position, the other is working. The scale of the camera tilt indicator - the washer (8) with the level (9) in figure 2 was graduated in three rows for shooting a spherical panorama. When using these lenses and a camera, 8 frames were required to overlap a viewing angle of 180 °. The camera was used in the "portrait" position.

Since under these conditions (crop factor 1.6) the ZENITAR-16M lens provides a viewing angle along the small side of the frame 54 °, the overlap of adjacent frames was (54 ° × 8-360 °) / 8 = 9 °.

This is about 16%. Thus, in order to obtain a spherical panorama, it was decided to shoot two closed rows of images and a floor image, a total of 8 + 8 + 1 snapshot.

The result of the panoramic image assembly exceeded all expectations. On such a large series of images, a stable overlap of neighboring images was obtained and parallax was practically absent.

Subsequently, when shooting indoors, when the flash was installed on the camera, it turned out that the weight of the flash makes it very difficult to keep the camera in the desired position. But we managed to make a series of frames to the end and get a good result. As an option to solve this problem, the use of an external flash controlled via a cable or an infrared transmitter is proposed. Almost all modern cameras have this feature.

For convenience, fastening the plumb line to the rods, it is advisable to use clamps. For example, screw, as shown in Fig.9. The thread clip can be of any type. In experiments, the conventional rubber tube (12), which provides simplicity and ease of control of the length of the thread, has proven itself well.

This greatly facilitates the adjustment of the length of the thread, depending on the growth of the photographer, or in the case of photographing elevated surfaces, for example above the surface of the table. To adjust the equality of the length of the threads, it is convenient to use a load with two perpendicular openings, in one of which there is a clamp, for example, a screw, and plumb threads freely pass through the others. The design of such a plumb line is shown in FIG. 10, where 13 is a plumb line retainer.

To control the angle of the camera, in addition to fixing the level (9), one can also use the option of attaching one of the threads to a movable washer (8) with a scale (11). The scaler is firmly connected to the rod. During tilting, the cylinder remains stationary, its position on the axis of rotation is fixed with a plumb line, and the pointer (10) moves with the rotating rod.

With a camera weighing more than a kilogram, the photographer’s hands are in great tension. Moreover, you need to constantly monitor three parameters: rotation, tilt, height. To reduce physical activity, it is proposed to use a neck tripod (a general view in action is shown in Fig. 12) with an emphasis on the trouser belt on one side and a small spherical head on the other end of the tripod. This head (14) is attached to the bottom of the lens holder (3), as shown in Fig. 13. From the place of attachment of the head (14) to the stop (16), a rigid neck tripod (15) is placed. The ends of the belt (18), which are hung on the user's neck, are hooked to the ends of the stop (16) for fastenings (17).

To solve the problems associated with the use of fisheye lenses, in which the front lens is often larger in diameter and the lens in this case has the shape of a cone, as well as for versatility using different lenses and lenses with variable focal lengths, an implementation of a device with mount to movable bar chamber.

On Fig shows a side view of such a camera (a) and top (b). The camera (1) has interchangeable lenses (2). By means of a screw (19), a shoe (20) is attached to the standard mount on the bottom of the chamber, having a guide (21) along which the bracket moves, with a U-shaped bracket (22) fixed to it with rods. The size of the bracket is selected so that the axis of the rods passes through the main optical axis of the camera-lens system.

The guide (21) moves in the slot of the shoe (20). Thus, it is possible to adjust the position of the axis of the rods along the optical axis of the lens. The result is a universal device limited to the type of camera. A general view of the operation of such a device is shown in FIG.

Although the present invention has been described with emphasis on preferred embodiments, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described and illustrated above. Various embodiments and adaptations, in addition to those shown and described herein, as well as many variations, modifications and equivalent devices clearly follow from the above description and drawings.

Claims (10)

1. The method of panoramic photography, characterized in that the shooting is done by positioning the camera with the lens in such a way that the condition for the rotation of the optical system around the nodal point located on the main axis of the lens and inside the lens system is ensured, the condition of the angle of inclination and the angle of rotation of the camera being constant , a condition for maintaining the position of the lens nodal point relative to the shooting point, characterized in that a lens holder with a lens rigidly attached to it is attached to the camera with the lens with threads located on the horizontal axis and perpendicular to the axis of the lens, and the ends of the rods are fastened with threads and weight so that this system is a two-strand plumb line, and the camera with the lens is fixed so that the axis of the rods passes through the nodal point, and around the camera to position the horizontal axis using a liquid bubble level fixed with a washer rotating on a horizontal axis of the washer on one of the rods, the angle of inclination of the chamber being determined according to the marks applied to the scale of the washer, and relative to the pointer, rigidly connected with the rod. 2. The panoramic photography method according to claim 1, characterized in that to obtain images of a spherical panorama, a template with a marked plumb point is placed on the surface where the photographer is standing, then the template is removed, and a plummet is positioned at this point, and the picture is taken. 3. The method of panoramic photography according to claim 2, characterized in that when shooting on the earth's surface using a solid template made of plastic, wood, metal or other materials. 4. The method of panoramic photography according to claim 2, characterized in that when shooting in water using a weighted template of material sinking in water. 5. The method of panoramic photography according to claim 1, characterized in that when fastening the plumb threads to the rods, clips of any type are used. 6. The panoramic photography method according to claim 1, characterized in that they use a neck tripod with an emphasis on the trouser belt on one side and a small spherical head on the other end of the tripod, the head being fixed at the bottom of the lens holder, and the ends of the belt hooked to the ends of the stop on the user's neck while shooting. 7. A device for panoramic photography, comprising a camera with a lens intended for panoramic photography, characterized in that it further comprises a lens holder attached to the camera with the lens with rods rigidly attached to it, located on the horizontal axis and perpendicular to the axis of the lens, and to the ends of the rods the threads and the load are fixed in such a way that this system is a double-thread plumb, and the camera with the lens are fixed in such a way that the axis of the rods passes through the nodal point at. 8. The device for panoramic photography according to claim 7, characterized in that the plumb line contains a pointer that is hinged, and one position of the plumb line pointer is the position for transportation, the other is working. 9. The device for panoramic photography according to claim 7, characterized in that a thick washer rotating around a horizontal axis is fixed to one of the rods, to which one of the threads of the double-thread plummet is attached, and a scale is applied on one side of this washer, and the scale pointer is rigidly connected with a rod. 10. The device for panoramic photography according to claim 7, characterized in that a liquid bubble level is fixed on one of the rods by means of a thick washer rotating around the horizontal axis, and a scale is applied on one side of this washer, and the scale pointer is rigidly connected to the rod.

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