Abstract:
A lighting stage comprising a floor and a turntable located on the floor and operable to rotate about a substantially vertical axis. The turntable has an upper surface to support an object, such as a vehicle, with a ceiling juxtaposed with and spaced from the upper surface. The ceiling has a downwardly directed reflective surface that extends laterally beyond the turntable. A peripheral wall extends from the ceiling to encompass at least a portion of the turntable and has an upper reflective portion and a lower absorbent portion. The upper portion and the ceiling smoothly merge to provide a continuously curved cove to provide the transition between the ceiling and the peripheral wall. A lighting assembly projects light on to the ceiling so that the ceiling and upper portion reflect and diffuse light towards the upper surface of the turntable to illuminate the object that is on the turntable.

Description:
BACKGROUND OF THE INVENTION 
     Advertising and promotional material require a high quality photograph of the product being marketed to project the correct image of the product. For this reason significant care is taken in the production of photographs, and in particular to the lighting of the object so that its features are clearly discernible and are presented in the most attractive manner. 
     One area that is particularly susceptible to the correct use of lighting is in the automobile area where the complex contours of a vehicle and the highly reflective surfaces require great care to ensure that the characteristics of the vehicle are properly displayed. Conventionally it has been appropriate to take single photographs of a vehicle from a particular position for use in brochures and catalogues. More recently, however, the use of the internet to display a vehicle on a manufacturer&#39;s or dealer&#39;s web site has required a series of photographs that simulate the movement of the viewer around the vehicle. The simulation of the movement around the vehicle can be achieved either by positioning the camera at different positions around the vehicle or, more conveniently, by having the vehicle rotate on a turntable to be photographed from a fixed position. The set of photographs obtained are then displayed successively to simulate rotation. In either case, it is necessary to ensure that the lighting on the vehicle is appropriate at all positions and ensure that the features of the vehicle are properly and consistently shown. 
     In one known arrangement, a light box is positioned above the vehicle as it is rotated on a turntable. However, the positioning of the light box and the rotation of the vehicle relative to the light box causes the highlighting of the upper surfaces of the vehicle to fluctuate as it rotates. The variations in the highlighting are apparent and relatively unattractive. Moreover, the light box is relatively expensive and its elevated position presents difficulties in supplying the power and controls for the lighting equipment. 
     There is, therefore, a need for a lighting stage in which the above disadvantages are obviated or mitigated. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention there is provided a lighting stage comprising a floor and a turntable located on the floor and operable to rotate about a substantially vertical axis. The turntable has an upper surface to support an object, such as a vehicle, with a ceiling juxtaposed with and spaced from the upper surface. The ceiling has a downwardly directed reflective surface that extends laterally beyond the turntable. A peripheral wall extends from the ceiling to encompass at least a portion of the turntable and has an upper reflective portion and a lower absorbent portion. The upper portion and the ceiling smoothly merge to provide a continuously curved cove to provide the transition between the ceiling and the peripheral wall. A lighting assembly projects light on to the ceiling so that the ceiling and upper portion reflect and diffuse light towards the upper surface of the turntable to illuminate the object that is on the turntable. 
     Preferably the cove is part spherical and is centred on the axis of rotation of the turntable. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings in which: 
     FIG. 1 is section through a lighting stage. 
     FIG. 2 is a plan-view of the lighting stage shown in FIG.  1 . 
     FIG. 3 is a view on the line  3 — 3  of FIG. 2 on an enlarged scale. 
     FIG. 4 is a development of a peripheral wall shown in the plan-view of FIG.  2 . 
     FIG. 5 is an enlarged view of a portion of the lighting stage shown in FIG.  1  . 
     FIG. 6 is a plan-view of a portion of FIG. 5 in the direction of arrow VI. 
     FIG. 7 is a view similar to FIG. 1 of an alternative embodiment of lighting stage and 
     FIG. 8 is a representation of a further modification of the lighting stage shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring, therefore, to FIG. 1, a lighting stage  10  is located within a studio building  12  that is used to support structurally the lighting stage  10  as necessary. The studio  12  has a roof beam  14  supported on side walls  16  and a floor  18 , all of which are of conventional construction. 
     The sound stage  10  includes a turntable  20  supported on the floor  18 , and having an upper surface  22  to support an object indicated at  24  that is to be photographed. The turntable is secured to the floor  18  and is rotatable about a generally vertical axis  30 . 
     The turntable  20  is located within a peripheral wall  26  that extends between the floor  18  and a ceiling  28 . The ceiling  28  extends laterally beyond the turntable  20  and, as can best be seen in FIG. 2, is circular in plan. The ceiling  28  is centred on the axis of rotation  30  of the turntable and the marginal portions of the ceiling  28  are formed as a curved cove  32 . 
     In the preferred embodiment the cove  32  is part spherical with its centre of curvature at the intersection of the axis  30  with the upper surface  22  of the turntable  20 . The cove  32  provides a smooth uniform transition between the plane of central portion of ceiling  28  and the upper edge of the peripheral wall  26  to avoid any sharp edges. 
     A lighting assembly is provided by a plurality of lights  34  that are disposed about the turntable  20  and are directed inwardly and upwardly to impinge upon the ceiling  28  and cove  32 . 
     As can be seen from FIG. 2 the peripheral wall  26  encompasses a portion of the turntable  20  and is spaced a constant distance from the periphery of the turntable  20 . The wall  26  projects forwardly from the turntable  20 , as indicated at  36 , and provides an enclosure at  38  for a camera  40 . The enclosure  38  has a pair of blinds  42  that may be drawn across the front of the enclosure  38  leaving an aperture for the lens of the camera  40  when in use. 
     Referring to FIGS. 3 and 4, the wall  26  is subdivided into an upper portion  44  and a lower portion  46 . The demarcation between upper and lower portions  44 , 46  provided by coatings of contrasting reflectivity so that the upper portion  44  is finished with a reflective flat paint, such as a white paint, and the lower portion  46  is finished with an absorbent coating  48 , 50 . The coating  48  which is provided on the forward extension  36  of the peripheral wall  26  is provided by a flat black paint and the finish  50  which extends around the turntable  20  is formed from a black absorbent material such as a short pile carpet. The inwardly directed surface  52  of the cove  32  and the downwardly directed surface  54  of the ceiling  28  are similarly finished in a reflective flat white paint that is the same as the finish on the upper portion  44 . It will be seen from FIG. 4 that the demarcation between the upper and lower portions  44 , 46  extends downwardly from either extremity along an inclined line  56  to a central well  58  in which the lower portion  46  is of reduced height. The well  58  is positioned on the peripheral wall  26  so as to be diametrically opposed to the camera  40 . 
     Referring again to FIG. 2, the upper surface  22  of the turntable  20  presents a generally planar support surface and is subdivided into areas of contrasting reflectivity. A central reflective band  60  extends across the upper surface  22  and is flanked by a pair of absorbent sectors  62 . The reflective band  60  is provided by a white flat reflective paint and the absorbent sectors  62  are provided by a flat black paint similar to that used as coating  48 . The extent of the central band  60  may be adjusted by utilizing a pair of covering strips  64 , 66 , shown in FIG. 5, which are made from an absorbent cloth material similar to that used on the covering  50 . The lateral spacing between the strip  66  can be adjusted to reduce the width of the reflective central band  60  as will be described more fully below. 
     The upper surface  22  of the turntable  20  is supported on a circular frame  68  with additional strengthening members  70 . The frame  68  and strengthening members  70  are supported upon wheels  72  distributed about the turntable that roll on the floor  18 . The turntable  20  is located relative to the floor  18  by a centre spindle  74  that carriers bearings  76  at its upper end to rotatably support the structure  68 , 70  and upper surface  28 . The turntable  20  is thus able to rotate about the spindle  74 . 
     Rotation of the turntable  20  is controlled by a motor  78  that drives a sprocket  80  mounted on the drive shaft  82 . The sprocket  80  engages a chain  84  secured to the circular frame  68 , The sprocket  80  is free to slide on the spindle  82  but is keyed to rotate with the spindle so that it may accommodate vertical displacement of the turntable as it rotates. The motor  78  is itself mounted on a plate  86  within a frame  88  so it may slide radially relative to the spindle  74 . The plate  86  is slideably mounted upon rods  88  with springs  90  biasing the plate  86  toward the spindle  74 . The sprocket  80  is thus biased into engagement with the chain  84  but its mounting assembly may accommodate radial run-out whilst maintaining driving engagement. 
     Control for the motor  78  is provided through a switch  92  that in turn is controlled by a timer  94  that maintains the switch closed for a predetermined interval after closing of a start switch  96 . An abutment  98  is secured to the frame  68  and engages a trip switch  100  that operates upon the switch  92  to stop the turntable  20  at a home position. 
     In operation the object  24 , in this case a motor vehicle, is driven on to the turntable  20  through the use of suitable inclined ramps (not shown) and is centrally positioned on the turntable  20  in alignment with the band  60 . The exact location of the vehicle on the turntable is carefully measured to ensure that it is centrally located over the axis of rotation  30 . Similarly, the camera  40  is carefully aligned so that its focal axis is centered on the axis of rotation  30 . The careful positioning of the vehicle and camera ensure that there is no orbital movement of the vehicle as the turntable rotates. 
     The reflective band  60  provides “uplighting” for the downwardly directed surfaces of the vehicle  24 . The degree of uplighting can be adjusted by movement of the strips  64 , 66  toward or away from the vehicle until the most desirable highlighting is obtained. The exact position of the strips  64 , 66  will depend to a certain extent upon the outer shape of the vehicle. The lights  34  are also positioned to provide a uniform reflected and diffuse lighting from the ceiling  28  so that the highlights on the upper surface of the car are properly displayed. The cove  32  ensures hat there is a uniform distribution of the light without a line caused by a hard edge being reflected in the body of the vehicle. Similarly, the uniform spacing of the wall  28  from the turntable  20  on the opposite side of the turntable to the camera  40  provides a uniform distribution of light about the vehicle. The lower portion  46  of the peripheral wall  26  absorbs incident light and inhibits the appearance of reflections in the outer surface of the vehicle. In this regard, the pile material  50  is found to be most effective at preventing significant reflection on to the vehicle, whereas in critical locations the paint  48  may cause such a reflection. However, the paint  48  is sufficiently effective in the lateral portions of the walls  36 . 
     The provision of the well  58  ensures that the black horizon does not appear through the windows of the vehicle as it rotates, which might otherwise cause post-production difficulties in processing the pictures for use on a web site or in advertising material. The gradually inclined edge  56  does, however, provide a progressive increase in the absorption of the light as the walls encompass the vehicle and provide the optimum diffusion and absorption of the light around the vehicle. 
     To initiate a photographic session, the turntable  22  is positioned in the home position and the shutters  42  positioned so as to obscure the camera operators and leave only a line of sight for the lens. The lights  34  are bounce flash units driven by suitable controls initiated from the camera  40  and effective to provide a short burst of high intensity light. The outer surface of the lights is black and a shroud may be provided over the rear surface of the light to inhibit reflection on the vehicle or into the field of vision of the camera. 
     With the turntable  20  positioned at the home position, an initial exposure of the vehicle is made and stored as a digital image on a computer. The start button  96  is pressed and the timer  94  operates the motor  78  to rotate the turntable for a short interval. It has been found that an interval sufficient to rotate the turntable approximately 10°, thereby giving thirty-six different positions of the vehicle relative to the camera has proven satisfactory for subsequent display of the vehicle on a computer in a rotating fashion. With the vehicle incrementally rotated, the next photograph is taken and stored as a computer file and the turntable further incremented. This sequence continues until the turntable again reaches the home position causing the stop  98  to trip the switch  100  and inhibit flirter movement. At each increment, a photograph is taken and stored on the computer. Upon completion of the set of photographs, the turntable  20  is rotated through 180 degrees from the home position enabling the vehicle to be driven off the turntable, down the ramps and out of the studio building  12 . 
     The set of photographs are then forwarded for post-production editing through a suitable program such as that available from Adobe Photoshop™ and prepared as a file for display on an internet web site or similar advertising medium. 
     The provision of the curved circular ceiling  28  ensures a uniform dispersion of the light from the light assembly  34  with adjustment of the uplighting available through the adjustment of the strips  64 , 66 . The uniform nature of the ceiling  28  and the peripheral wall  26  ensures that the highlighting of the vehicle remains constant during its rotation producing a pleasing overall effect when the photographs are assembled as a set and displayed sequentially to simulate rotation. 
     In a typical installation, by way of example only, the diameter of the turntable  20  is 24 ft., the height of the ceiling  28  above the turntable is 15 ft. and the diameter of the outer edge of the cove  54  where it meets the peripheral wall  26  is 54 ft. Other dimensions may of course be used to suit particular circumstances. 
     An alternative arrangement is shown in FIG. 7 in which the free standing lights  34  are replaced with a elevated set of lights  134  mounted adjacent to the ceiling  128 . The lights  134  are supported on an opaque platform and the light is projected upwardly on to the under surface of the ceiling  128  for diffusion on the vehicle. 
     In a further embodiment illustrated in FIG. 8, the demarcation between upper and lower portions  244 , 246  is adjustable by forming the lower portion out of a fabric that may be elevated through guidewires over pulleys to adjust the position and inclination of the horizon provided by the demarcation between the upper and lower portions.