GB2411736A

GB2411736A - Photographic and video apparatus utilising the golden ratio

Info

Publication number: GB2411736A
Application number: GB0404807A
Authority: GB
Inventors: Patrick Marcus Thompson
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-03-03
Filing date: 2004-03-03
Publication date: 2005-09-07
Also published as: GB0404807D0

Abstract

Viewfinders for still or video cameras, a ground glass for movie cameras or viewfinders, or a projector gate or screen, is arranged to utilise the 'Golden Ratio' of ( ! 5+1)/2:1 as an aspect ratio. Preferably, the ground glass or viewfinder is provided with composition lines, points or other markers, which divide dimensions of the image in accordance with the ratio of ( ! 5+1)/2:1, to assist in composition of an image. A ground glass or viewfinder composition grid 1 is shown where width w and height h are in the golden ratio of 1.618. Horizontal composition lines 2a,2b taken individually divide the height h into two in accordance with the golden ratio. Similarly, width w may be divided by vertical composition lines 3a, 3b.

Description

241 1 736 Photographic and Video Apparatus Utilising the Golden Ratio The

present invention relates to photographic and video apparatus.

Background

There is a mathematical ratio found in nature, which is sometimes known as the Golden Ratio or Divine Proportion. A rectangle having sides which are proportioned according to this ratio (a 'Golden Rectangle') has the property that, if it is divided to form a square having sides equal to the shorter sides of the rectangle, the remaining smaller rectangle has the same proportions as the original rectangle. Alternatively, if a new rectangle is created by swinging the long side of a Golden Rectangle around one of its ends to create a new long side, the new rectangle is also a Golden Rectangle.

The value of the Golden Ratio can be shown to be (45+1)/2, or approximately 1.618:1.

Pythagoras demonstrated in the 6th Century BC that various aspects of the human figure are proportioned in accordance with this ratio, and the same proportions were adopted in Greek art and architecture.

The Golden Ratio is also connected closely with the Fibonacci Sequence (1, 1, 2, 3, 5, 8, 13, 21, 34, 55, ...), in which each number is the sum of the two preceding numbers. As this sequence proceeds, the ratio between adjacent numbers becomes closer to the Golden Ratio. The Fibonacci Sequence models certain natural processes, and the numbers of the sequence are often found in nature. For example, on many plants, the number of petals is a Fibonacci number, and many seed and flower heads, are arranged in accordance with the numbers of the sequence.

As a result of its significance in nature, the Golden Ratio is often considered to form the basis of particularly aesthetically pleasing arrangements and visual relationships. Studies of great works of art have shown that their composition and proportions often follow the Golden Ratio. In particular, key features may be located such that they divide a space in accordance with the Golden Ratio. This is also referred to as the Golden Section.

The Golden Section divides a dimension into two parts having the ratio (45+1)/2:1. This can be seen in the Golden Rectangle, where the Golden Section divides the rectangle into a square and a smaller rectangle which is also Golden.

Further subdivisions can be made in accordance with the Golden Section, to provide various divisions of the space in accordance with the Golden Ratio.

As an example, it has been observed in many paintings that features are positioned in accordance with the Golden Section, such that they divide the canvas in the Golden Ratio, and that this is considered to provide an aesthetically pleasing composition. Key features (e.g. a horizon) may divide the canvas in the Golden Ratio, and other features may then represent further subdivisions of the remaining spaces in accordance with the same ratio.

Furthermore, as has also been reflected in architecture, shapes proportioned in accordance with the Golden Ratio are themselves often considered to be aesthetically pleasing, in addition to the use of the Golden Section to proportion features within those shapes. Hence, for example, the front elevation of the Parthenon has its width and height proportioned in accordance with the Golden Ratio, as well as using the ratio in different aspects of its decoration.

In the history of motion pictures, there have been many different film formats and aspect ratios. The 35mm standard has an aspect ratio of 1. 33:1, later altered to 1.37:1 ('Academy' format) with the addition of sound on film, and this is still reflected in television, 8mm and 16mm film. Film shot using this aspect ratio can be shown in a wider aspect ratio, by composing a movie in the centre of the frame, and masking the top and bottom of the frame when projected onto the screen. This technique was used from the 1950s to show movies in aspect ratios of between 1.5:1 and 1.85:1.

An interest in the cinematic experience of projecting movies in widescreen formats led to the development of a technique in which an anamorphic lens is used to impart a horizontal 'squeeze' into the image recorded onto film. A complementary anamorphic lens is then used on the projector to expand the squeezed image onto the screen. In this way, using a 100% horizontal squeeze, a greatly increased aspect ratio (2.66:1) could be achieved using conventional film.

However, the size of the original anamorphic adapters was restrictive in the kinds of lenses which could be used in filming, but the technique was nevertheless successful.

A technique was also developed to add magnetic stripes to the film, to carry the soundtrack, instead of using a separate 35mm film synchronized with the picture projector. This took up additional space on the film, at the expense of some of the aspect ratio, and the CinemaScope system adopted anamorphic lenses with a 100% squeeze, as well as magnetic sound stripes, resulting in an aspect ratio of 2.55:1.

With the development of a combined magnetic and optical sound print, the ratio was further reduced to 2.35:1, although a subsequent reduction in recommended aperture height has resulted in a ratio of 2.4:1.

The conventional analogue sound track is included on one side of the film, between the sprocket holes and the image, in the form of stripes running in the direction of the film.

Other techniques have been used, such as producing wide aspect ratios by using a cropped portion of a conventional 1.33:1 frame, but improving quality by using large format film.

The most popular systems now use aspect ratios of 2.35:1 or 1.85:1. A ratio of 2.35:1 can be achieved using anamorphic lenses, and 1.85:1 can be achieved by using the cropped central portion of a narrower frame.

The standard for widescreen televisions and DVD video has become the 16:9 aspect ratio (1.78:1), which is a compromise between the narrow Academy frame and the 2.35:1 ratio commonly used in cinemas.

It can be seen that the widescreen formats used in motion pictures have developed in a relatively arbitrary manner, often in response to technical convenience.

When filming motion pictures, it is known to use optical ground glass inserts which overlay the scene as viewed through a viewfinder, and which are marked to show guide points of lines to assist in composing the shot. The ground glasses may indicate the outline of the intended viewable area of the film, as well as other compositional markers.

Similarly, viewfinders in other kinds of cameras, such as digital still or video cameras may include indicators relating to the edges of the output picture or other markers.

Summary of the Invention

It is an object of the present invention to assist a user in composing aesthetically pleasing pictures, when using still or video/flm cameras by providing, in different aspects, improved ground glasses and viewfinder systems. It is a further object to provide a movie filming and projection system, which allows a visually pleasing image format to be committed to conventional 35mm film and played back.

The present invention provides a ground glass for use in a camera or viewfinder, the ground glass indicating an image aspect ratio of (<S+1) /2:1. The ground glass may itself be shaped to have this aspect ratio, or frame lines may be provided.

Preferably, the ground glass includes composition lines, points or other markers, which divide dimensions of the image in accordance with the ratio of (15+1)/2:1.

The invention also provides a ground glass system comprising the ground glass described above, and means for illuminating the composition markers and/or frame lines to allow improved visibility in low light, and may include means for altering which markers or lines are visible at one time.

The invention also provides a viewfinder, and a video or still camera incorporating the viewfinder, which indicates an image outline having the aspect ratio of (45+1)/2:1. The aspect ratio may be indicated by the aspect ratio of the viewfinder itself or by frame lines. Preferably, the viewfinder includes composition lines, points or other markers, which divide dimensions of the image in accordance with the ratio of (5+1)/2:1. Preferably the viewfinder is arranged to illuminate the composition markers and/or frame lines to allow improved visibility in low light, and may include means for altering which markers or lines are visible at one time.

The viewfinder of the invention may be implemented in a TTL still camera viewfinder or an LCD panel, and fiber-optic illumination may be provided.

The invention may also be implemented in a format mask, camera, camera aperture, CCD sensor, projector, projector aperture or gate, projection screen, enlargement filter, etc. utilising an image aspect ratio of (5+1) /2:1.

By using the Golden Ratio of (45+1)/2:1 as the aspect ratio for still or video pictures, a picture format is provided, which takes advantage of the natural impact of this shape in producing a particularly pleasing visual effect.

The ground glass or viewfinder enables the user to see the outline of the image having this aspect ratio, when composing the shot. Furthermore, the composition lines utilising the Golden Section points assist in the composition of the key features of the image within the Golden Ratio outline. The particular combination of the Golden Section points within the Golden Ratio aspect image enables the user more easily to produce aesthetically pleasing images.

Preferably, in the illuminated viewing systems, the operator can illuminate not only the Golden Ratio aspect aperture frame lines, but also the precise Golden Section composition points or grids, and can vary the number of grid lines visible at any time, in order to assist in composing different aspects of the image.

Drawings Embodiments of the invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows how images of different aspect ratios are accommodated onto 35mm film frames; and Figures 2 to 10 illustrate different arrangements of ground glasses according to the invention, including composition markers which may also be used in viewfinders.

Embodiments of the Invention The use of the Golden Ratio as the aspect ratio of an image with 35mm film combines the effect of a particularly pleasing image shape with an advantageous use of the space in the 35mm frame, without requiring the use of anamorphic lenses.

With the introduction of digital sound systems (e.g. Dolby (RTM) SRD, DTS and SDDS) into the presentation of 35mm films, it is no longer necessary to combine an analogue optical soundtrack onto a positive print. Until recently, the provision of the optical track has been required to accommodate theatres not equipped to read digital systems, or alternatively at least as a backup in case the digital system should break down.

Now that projectors have the ability to carry more than one digital signal reading system, the need for the optical track is obsolete in many theatres worldwide.

Should one digital system fail, the projectionist can switch over to an alternative system, since most prints now carry all systems.

This means that the area of a 35mm print frame once dedicated to the optical sound track can now be used for the picture image. This is known when shooting negative film as Super 35, where the full frame is exposed from sprocket hole to sprocket hole across the film, and wide screen or 'letterbox' shots are composed by masking. Conventionally, once edited, films that have been shot using the Super 35 system are re-photographed frame by frame, or 'squeezed' optically to fit onto an Academy sized frame, requiring anamorphic projection lenses to extract the correct image when projected.

Using the system of the present invention, almost the entire 35mm negative area is exposed to the image using the aspect ratio of (45+1)/2, thereby both utilising the film area effectively and producing a particularly visually appealing image shape.

Once the film has been edited, positive prints can be made directly from the cut negative or internegative without masking or 'squeezing', and the digital sound data can be accommodated in a conventional manner, without diminishing the positive print area.

Figure l(a) shows how an image having an aspect ratio of 1.85:1 is positioned in a 35mm film frame, leaving space for an optical sound track (5) on one side of the frame. Figure l(b) shows a wider, 2.35:1 image in a Super 35 format, utilising the whole width of the frame from sprocket hole to sprocket hole. Figure l(c) illustrates how the system of the present invention can use the aspect ratio of (45+1)/2:1 to efficiently utilise the space in the frame, while at the same time providing in image with what are specifically determined to be aesthetically pleasing proportions.

The Golden aspect ratio can also be used advantageously with film formats other than 35mm, and still produce a pleasing image shape which also utilises the print area efficiently.

The images can be framed and composed using ground glasses such as those shown in Figures 2 to 10. These ground glasses indicate the outline of Golden aspect ratio which is to be used, in order to assist in framing the image. However, these glasses also provide composition points or lines which utilise the Golden Section to assist in the composition of the image within the Golden Ratio outline.

Not only does this provide composition points using the Golden Section to assist in composing a pleasing image, but the use of such points within the frame having an aspect ratio according to the Golden Ratio combines to facilitate the composition of particularly pleasing shot.

Figure 2 shows an example of a ground glass or viewfinder composition grid (1) utilising the Golden Ratio as its aspect ratio, and various Golden Section composition lines. Width w and height h are in the ratio (45+1)/2:1, in order to show the Golden Ratio image frame. Horizontal composition lines (2a, 2b) are positioned such that each one, when taken individually, divides height h into two parts in accordance with the Golden Ratio. One line (2a) is an upper Golden Section, and the other (2b) is a lower Golden Section.

Similarly, width w is divided by primary Golden Section vertical composition lines (3a, 3b). For example, one vertical line (3a) divides width w into two lengths, w' and w2, such that the ratio of w2:w' is (5+1) /2:1. Secondary Golden Section vertical composition lines (4a, 4b) further divide the smaller sections defined by the primary composition lines (3a, 3b). For example, one vertical line (4a) further divides length w' into two lengths, we and we, such that the ratio of w'2:w'' is also (45+1)/2:1. Further subdivisions may be included in the composition grid as desired, which continue to follow the Golden Section principle.

Figures 3 to 6 show alternative arrangements of the composition grids used in the ground glass or viewfinder, all utilising the Golden Ratio as the aspect ratio, as in Figure 2. Horizontal composition lines (12a, 12b) are provided, and positioned in the same way as the horizontal lines (2a, 2b) in Figure 2, except that the lines only continue from the edge of the rectangle to the point where they intersect with vertical lines (13a, 13b) which are positioned in the same way as the primary vertical composition lines (3a, 3b) in Figure 2. This provides an alternative composition grid to that shown in Figure 2, but shows fewer lines in the centre of the frame. Also, secondary composition lines are not provided in this example.

Figure 4 shows another arrangement of a grid (20), similar to that of Figure 2, but where only short markers are provided at the edge of the frame, in the positions corresponding to the Golden Section locations of Figure 2. Thus, there are provided horizontal composition markers (22a, 22b), and primary (23a, 23b) and secondary (24a, 24b) vertical markers.

Figure 5 shows a grid (30) in which only the centre rectangle of Figure 2 is marked, by displaying central portions of the horizontal composition lines (32a, 32b) and primary vertical composition lines (33a, 33b). The lines extend slightly beyond the corners of the rectangle formed in this way, in order to provide markers to assist in composing the rest of the frame.

Figure 6 shows a grid (40) in which, as in Figure 4, only short markers (42a, 42b, 43a, 43b) are provided at the edge of the frame, in this case in the positions of the primary horizontal and vertical Golden Section lines. Here, further cross markers (45) are provided at each point of intersection of the notional primary horizontal and vertical Golden Section lines, to provide four markers corresponding to the corners of the central rectangle of Figure 5.

It will be appreciated that many variations of the Golden Section composition grids and markers are possible, the common feature being the use of the Golden Section to divide the frame in accordance with this defined aesthetically pleasing compositional ratio. Figures 7 and 8 show other examples, Figure 7 including further subdivisions of the frame, and Figure 8 including diagonal markers.

It will be further appreciated that only key Golden Section points may be indicated, such as in the arrangement of Figure 9, in which two dots (71, 72) are provided, but the two dots indicate between them the vertical and horizontal positions of both of the primary horizontal and both of the primary vertical Golden Section lines. This is because one dot (71) lies at the intersection of the notional upper horizontal primary Golden Section line and one of the notional vertical primary Golden Section lines, and the other dot (72) lies at the intersection of the notional lower horizontal primary Golden Section line and the other of the notional vertical primary Golden Section lines. Figure 10 shows an example of how the same information can be shown using four short dashed markers (81, 82, 83, 84) towards the edges of the frame, one lying on each of the primary horizontal and vertical Golden Section lines.

On projection, using the system of the invention, a gate having the Golden aspect ratio is inserted into the projector, to maintain the correct aspect ratio in the projected image. The picture originally captured onto the full negative frame is now projected onto the screen using standard spherical lenses. The use of this system results in an image which is not only larger than a traditional widescreen anamorphic picture, but only requires standard spherical lenses, which means that less glass is required, resulting in a brighter image. This combines with the fact that the aspect ratio is specifically derived to give a visually pleasing shape, to result in a particularly convenient and attractive format.

The projected image is preferably displayed on a screen having the same aspect ratio of(l5+1)/2:1.

Below are examples of 35mm film and projector formats which may be used in accordance with the system of the invention.

Standard Golden Aspect Ratio NEGATIVE SPECS: Film Gauge: 35mm Direction of travel: Vertical - four perforations - 24 lips Camera Optics: Spherical Aperture Dimensions: 0.825" x 0.509" Gate (depending on camera model) Maximum Aspect Ratio: 1.61803:1 (Golden Ratio) PRINT SPECS: Film Gauge: 35mm Direction of travel: Vertical - four perforations - 24 lips Projector Optics: Spherical Aperture Dimensions: 0.825" x 0.509" Maximum Aperture Ratio: 1.61803:1 (Golden Ratio) Sound Format: DTS / SRD With this system, the camera and projection apertures share identical dimensions, and the soundtrack area is reserved for the optical soundtrack.

Super Golden Aspect Ratio NEGATIVE SPECS: Film Gauge: 35mm Direction of travel: Vertical - four perforations - 24 sips Camera Optics: Spherical Aperture Dimensions: 0.945" x 0.584" Full Gate (depending on camera model) Maximum Aspect Ratio: 1.61803:1 (Golden Ratio) - ground glass may display a 2.35:1 frame and the Golden frame PRINT SPECS: Film Gauge: 35mm Direction of travel: Vertical - four perforations - 24 lips Projector Optics: 2 x Anamorphic squeeze Aperture Dimensions: 0.825" x 0.690" Maximum Aperture Ratio: 2.4:1 (with squeeze) Sound Format: DTS / SRD and Optical Here, the negative is shot using the full width of the film between sprocket holes, and the print uses the conventional width of 0.825", allowing space for the optical sound track, but utilising a horizontal squeeze to give a maximum aspect ratio of 2.4:1 when projected, using an anamorphic lens.

Although, for example, a Panavision camera may have a full gate width of 0.980" when converted for super 35mm use, the maximum width available when using a mask or gate is generally 0.945". In this case, a gate may be used to achieve the desired Golden aperture aspect ratio.

Here, the ground glass is used to assist in framing and composition of pictures, by utilising the Golden Section composition guidelines, within a conventional anamorphic context. The precise aperture sizes may vary with different cameras, but the aperture should be as wide as possible, with the appropriate frame height corresponding to the Golden Ratio.

Ultra Golden Aspect Ratio NEGATIVE SPECS: Film Gauge: 35mm Direction of travel: Vertical - four perforations - 24 fps Camera Optics: Spherical Aperture Dimensions: 0.980" x 0.605" Full Gate (depending on camera model) Maximum Aspect Ratio: 1.61803:1 (Golden Ratio) PRINT SPECS: Film Gauge: 35mm Direction of travel: Vertical - four perforations - 24 fps Projector Optics: Spherical Aperture Dimensions: 0.980" x 0.605" Maximum Aperture Ratio: 1.61803:1 (Golden Ratio) Sound Format: DTS / SRD (no optical) With this system, the camera and projection apertures again share identical dimensions, but the full width of the frame is used in both the negative and the print, such that the optical soundtrack area is used for the projected image, and the sound is exclusively digital.

In the above specifications, a frame rate of 24fps is used, although it is also possible to run at a speed of 25fps, depending on whether filming is being carried out for television.

It will be appreciated that the Golden Ratio may be used as the aspect ratio in other film formats. For example, a camera aperture gate of 0. 368" x 0.227" (9.347mm x 5.765mm) would provide a standard 1 6mm film size, but in the aspect ratio of (15+1)/2:1, and a gate of 0.470" x 0.2904" (11.938mm x 7. 376mm) would provide a Super 16 format with this aspect ratio.

In addition to its use with film and projection, the Golden aspect ratio and Golden Section composition markers can be implemented in different applications. For example, in the light of the popularity of photography and movie making as hobbies, using various different recording media, it is particularly advantageous to provide viewfinders in digital still and video cameras which show Golden Section composition markers as described above. This assists amateur photographers and movie makers In composing pleasing Images.

More advantageously still, the Golden aspect ratio may be adopted as an image format for the resulting still and video images. Digital cameras can then output images using this aspect ratio, and viewfinders can indicate this outline (or be shaped in this aspect ratio) in combination with, or as an alternative to, the Golden Section markers to assist in composition. The Golden Ratio format may be a selectable option in addition to, for example, 4:3 and 16:9 formats commonly provided in digital cameras, particularly video cameras such as DV and mini DV cameras. Digital cameras may be provided with a Golden aspect ratio CCD sensor.

Analogue cameras can also be provided with viewfinders displaying the same aspect ratio and composition markers.

Preferably, analogue or digital still images are printed in the aspect ratio of (45+1)/2:1. Enlargement filters utilising this aspect ratio can be used during enlargement and printing.

Claims

Claims: 1. A ground glass for use in a camera or viewfinder, the ground

glass indicating an image aspect ratio of (15+1)/2:1.
2. A ground glass according to claim 1, further including composition lines, points or other markers, which divide dimensions of the image in accordance with the ratio of(<S+1)/2:1.
3. A ground glass according to claim 1 or 2, wherein the ground glass has an aspect ratio of (45+1)/2:1.
4. A ground glass system comprising a ground glass according to any preceding claim, and means for illuminating the indication of the image aspect ratio, and/or composition markers.
5. A ground glass system according to claim 4, further comprising means for altering which markers or lines are visible at one time.
6. A viewfinder which indicates an image outline having the aspect ratio of (15+1)/2: 1.
7. A viewfinder according to claim 6, further including composition lines, points or other markers, which divide dimensions of the image in accordance with the ratio of (5+1)/2:1.
8. A viewfinder according to claim 6 or 7, wherein the viewfinder has an aspect ratio of (15+1)/2:1.
9. A viewfinder according to any of claims 6 to 8, further comprising means for illuminating the indication of the image aspect ratio, and/or composition markers.
10. A viewfinder according to claim 9, further comprising means for altering which markers or lines are visible at one time.
11. A viewfinder according to any of claims 6 to 1O, wherein the viewfinder comprises an LCD panel.
12. A video or still camera incorporating a viewfinder according to any of claims 6 to 12.
13. A filming system comprising a camera having aperture means arranged to record an image on a film, the image having an aspect ratio of (45+1) /2:1, and a viewfinder arranged to frame the image to be recorded on the film, the viewfinder indicating the aspect ratio of (N15+1)/2:1.
14. A filming system according to claim 13, further comprising a ground glass through which the image to be recorded can be viewed by an operator, and means for receiving the ground glass, the ground glass indicating an aspect ratio of (N|5+1)/2:1 and including composition lines, points or other markers, which divide dimensions of the image in accordance with the ratio of (45+ 1)/2:1.
15. A projection system comprising a projector having aperture means arranged to project an image, the image having an aspect ratio of (45+1) /2:1.
16. A projection system according to claim 15, wherein the aperture means comprises a projector gate having an aspect ratio of (N15+1)/2:1.
17. A projection system according to claim 15 or 16, further comprising a screen suitable for displaying the image projected by the projector, the screen having an aspect ratio of (5+1)/2:1.