Abstract:
An automated studio and control system for taking photographs is disclosed that alleviates many exposure problems and simplifies variables with which the photographer must deal in order to achieve consistent high quality photographs. The studio includes a multi-light portrait lighting system, a subject location verification system and a system for varying backgrounds, all of which are tied to an integrated control system and synchronized to a camera.

Description:
The following application is a continuation application of U.S. patent application Ser. No. 10/959,655, filed on Oct. 6, 2004. 

   BACKGROUND OF THE INVENTION 
   I. Field of the Invention 
   The present invention relates generally to commercial studio portrait photography and, more particularly, to an automated control system and method for portrait composition that coordinates lighting aspects, backgrounds, subject location and synchronizes camera operation. 
   II. Related Art 
   Commercial studio portrait photography has evolved from the use of tripod-mounted cameras to hand-held cameras. In addition, subjects are being photographed on the floor with many different shades of backgrounds. These techniques have advantages, but serious exposure problems have also been encountered which affect product quality and impede required production efficiencies, particularly in high volume studios. 
   The problems are of several types. Subjects not on a predetermined pose line or mark can be over or under exposed. For example, if the subject(s) are in front of the pose line, they will be overexposed because they are closer to the lights. Conversely, if the subjects are behind the pose line, they will be underexposed because they are further from the lights. The use of different backgrounds also poses certain problems. The exposure of subjects on the floor varies with the use of light or dark backgrounds. Light backgrounds tend to overexpose the subject because of increased reflection of light onto the subject. Dark backgrounds, on the other hand, tend to lead to underexposed subjects because they absorb light that would normally be reflected onto the subject. Each shade of background (light to dark) requires a commensurate correct amount of background light illumination. For example, overexposing a black background by using too much “background light” causes a black background to wash out to a grayish color. Conversely, white backgrounds look grayish if underexposed by not having sufficient “background light”. 
   It has also been found that often subjects are photographed too fast, that is, the exposure is made before the illuminating lights can properly recharge, for example, which causes underexposure. This is particularly true in the case of recharging strobe power packs. 
   Variations also occur due to the location of the lights relative to the subject being photographed. Thus, photographing subjects on the floor requires the photographer to move the lights down, otherwise the subject will be underexposed. Conversely, if the subject is standing, the lights need to be moved up or the subject will be overexposed. 
   Other lighting parameters which affect the quality of studio portrait photography include the positioning of studio lighting and variation in “lighting ratios”. “Lighting ratios” is a term used in the art to describe the relative differences in power between the main and fill lights used in photographing a subject. The “main light” refers to the lights used to generally illuminate the subject (equivalent to the sun in outdoor photography). This light is generally controlling and is what the photographer starts with when composing the scene in a photograph. “Fill lights” are non-directional lighting used to highlight the scene or subjects(s). The “lighting ratio” refers to the relative ratio between the main and fill lights. The skilled photographer needs to know what ratios are best for what situation and how to mathematically calculate these values. For example, a 1:2 lighting ratio (flat) provides excellent results when photographing family groups. On the other hand, a 1:7 lighting ratio (high contrast) is preferred for dramatic individual low-key photography (black background). It has also been found that the position of the main light relative to the subject(s) is critical to the lighting ratio chosen and to the background that is chosen. 
   Given the above, it will be readily recognized that there are many important variables with which the photographer must deal in order to achieve consistent high quality photographs. Compound this with the need for a rapid throughput in high-volume commercial portrait photography business which puts a heavy burden on the photographer. Even small, low-volume studios find dealing with all the variables, combinations and situations very difficult to manage successfully. 
   Integrating all the available tools including the ability to change lighting ratios presents a definite sustainable competitive advantage, and automation of such techniques would be a very desirable improvement. Such automation would also facilitate training of photographers to achieve uniform excellent results. 
   SUMMARY OF THE INVENTION 
   By means of the present invention, there is provided an automated studio and control system for taking photographs that alleviates many exposure problems and simplifies the variables with which the photographer must deal in order to achieve consistent high quality photographs. The studio includes a multi-light portrait lighting system, a subject location verification system and a system for varying backgrounds, all of which are tied to an integrated control system and synchronized to a camera. 
   The exemplary detailed embodiment includes a four-light portrait lighting system which includes a main light capable of being located at a plurality of positions and heights relative to the location of a subject to be photographed, a fill light, a background light and a hair illuminating light. Each light may be controlled both for on/off and power level. Operation of all four lights is coordinated with other lights and camera operation. The system also includes a subject position locator on the floor of the studio which may be a pose line or mark. A sensor is provided that detects whether the subject(s) are on the pose line or otherwise in a predetermined position for being photographed. The system includes an ultra-sonic sensor which also detects whether the subjects are standing, sitting on a stool or on the floor. The sensor is attached to a position light so that the photographer can visually tell if the subject(s) are on the pose line. A background track is located behind the subject position along which a variety of backgrounds can be mounted. A plurality of backgrounds are available which include light backgrounds, white backgrounds, medium backgrounds and black or other dark backgrounds which can be interchanged as desired. A unique pattern of magnets is located on each type of background. Rows of magnet-detecting sensors in fixed locations identify the particular background being used. 
   The system is controlled preferably using a programmable logic controller (PLC). Inputs to the controller include signals based on sensing whether the subject or subjects are on the pose line or mark and whether they are on the floor, standing or sitting. Other sensors provide signals based on sensing the up and down position of the main light and the position of the main light relative to the pose line. Also, the shade of the background being used is sensed and the enablement of the camera and/or synchronization is controlled. A variety of audible buzzers and visual LED indicator lights may be used to interface with the photographer and present information as to the status of exposure variables. Thus further enables the photographer to make informed adjustments in subject position, increase lighting ratio or other modifications as indicated prior to making the exposure. The controller controls the output of all lights and, based on sensor inputs, enables a plurality of lighting ratios to be implemented with a single control button. 
   A communication link is maintained between the control system and the camera. 
   Synchronization of camera operation generally includes: 
   A. A programmable delay to ensure that the lighting is ready, i.e., is recycled (typically using a recharging strobe power pack). 
   B. The proper position of the subject or subjects with respect to the pose line. 
   C. The up/down position of the main light. 
   D. The position of the main light on the main light track. 
   E. The correct main light modifier/baffle. 
   Once all the variables are coordinated, the camera is enabled and the photograph may be taken. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings, wherein like numerals depict like parts: 
       FIG. 1  is a schematic representation depicting a commercial portrait studio set up using a photography system in accordance with the invention; 
       FIG. 2  is a schematic control system diagram for the photographic system of  FIG. 1 ; 
       FIGS. 3   a - 3   d  show certain detail elements of the control system of  FIG. 2 ; 
       FIG. 4  is a chart depicting certain exposure problems and solutions using the control system of the invention; 
       FIG. 5  is a flash lighting ratio chart based on position and background types showing corrections in accordance with the invention; and 
       FIGS. 6   a - 6   e  are charts that show combinations of lighting settings for various backgrounds with different main light positions as implemented by the control system of the invention. 
   

   DETAILED DESCRIPTION 
   The apparatus and control systems of the invention are designed in combination to address and overcome many common problems encountered in relatively high volume commercial photo studio experience which tend to affect product quality. The invention, however, is equally applicable to any studio seeking consistent high quality photographs. The system described in detail herein is presented by way of example and is not intended to limit the scope of any aspect of the inventive concept. 
     FIG. 1  is a schematic representation of a commercial photo studio  10  showing the main elements of the system of the invention. A background system, generally at  12 , permits the backgrounds used to be altered and automatic adjustment of the system based upon the background selected. A four-light portrait lighting system is employed which includes a main light system  14 , a fill light as shown at  16 , a background light at  18  and a hair light at  20 . Each light is controlled both for on/off and power level as will be explained. A cabinet  22  contains a strobe power pack for controlling lighting at  24  and a control system indicated by  26 . A subject  28  is depicted on a stool  30  which may be positioned based on a positioning mark or pose line (not shown) on the floor of the studio. 
   An ultra-sonic sensor  32  is positioned above the pose line so as to sense the presence of a subject and to detect whether the subject is in proper position with respect to the pose line to be photographed. As will be described, the ultra-sonic sensor  32  is linked to a controller which locks out or prevents operation of an associated camera if the sensor  32  fails to verify the presence of a subject to be photographed in the proper position with respect to the pose line and, conversely, unlocks or enables an interlock associated with the operation of the camera when the subject to be photographed is in proper position. As will be described, additional interlocks associated with other aspects of the system must also be enabled for the camera to operate. The sensor also senses whether the subject is standing (elevated) or sitting on the floor. The sensor  32  is attached to a position light  33  so that the photographer can also visually tell if the subject or subjects are on the pose line. 
   The background system includes a default background and a rail or track between the default background and the locations where subjects to be photographed are to be positioned. A variety of available backgrounds can be mounted to the rail or track. These include five basic backgrounds including light  34 , white  36 , gray  38 , black  40 , and other dark backgrounds  42 . They are mounted along a track system generally at  35 . As can best be seen in  FIG. 3   a , the backgrounds are provided with magnetic sets which are correlated to background sensors as at  44  (position  3 ),  46  (position  2 ) and  48  (position  1 ).  FIG. 3  illustrates a possible magnet and sensor configuration for five different backgrounds in which light backgrounds are provided with one magnet set on the right side of the background; white backgrounds are provided with one magnet set in the middle of the background; and gray backgrounds are provided with one magnet set on the left side of the background. Black and dark backgrounds are provided with two magnets with black backgrounds having one on the right and one of the left side of the background; and other dark backgrounds are provided with one magnet on the right and one in the middle of the background. Thus, depending on where magnets are sensed, the background sensing system will identify the background and adjust the light level on the background accordingly. Alternative background identification systems can be used without deviating from the invention such as a unique bar code applied to each background and a bar code reader mounted to the rail or track capable of reading the bar code and transmitting signals to the controller. Video identification of the backgrounds is another method that could be used. Also, additional tracks  35  can be provided for enhanced flexibility. 
   The main light system  14  of the four-light portrait lighting system includes a main light rail  50  which is provided with an array of main light position sensors as at  52 ,  54 ,  56  and  58  which correspond to four discreet positions ( 1 ,  2 ,  3 ,  4  in  FIG. 2 ) from which a main light  60  may be suspended at multiple heights utilizing a suspension arrangement as at  62 . The light  60  may be provided with an up/down switch, preferably a micro-switch, as at  64  to indicate whether the light  60  is in an up or down position. A main light modifier sensor  66  may also be provided to indicate whether a baffle or other modifier, or no modifier is in place with respect to the main light. 
   A schematic block diagram of an automatic portrait lighting control system to control a studio in accordance with  FIG. 1  is depicted in  FIG. 2  and certain additional details are depicted in  FIGS. 3   a - 3   d . As can be seen in  FIG. 2 , the heart of the control system is a programmable logic controller (PLC)  70  which operates in conjunction with several control panels having indicator lights, including an ultra-sonic indicator panel  72 , a main light control panel  74  and a general control panel  76 . Front and back background sensing tracks are shown at  78  and  80 , respectively, and relative subject location are indicated in the dashed-line box  82 . A synchronized camera is shown at  84 . Communication links are shown at  86  and  87 . 
   The PLC  70  receives a variety of signals and processes these signals to control the operation of the lights and camera. Specifically, the PLC  70  receives signals from (a) the ultra-sonic sensor  32  indicative of the presence and height of a subject to be photographed in the correct position; (b) the background system indicative of which background will be in the picture; (c) the main light system indicative of the position and height of the main light as well as whether a modifier/baffle is in place over the main light. The PLC  70  processes these input signals in response to a programmed set of instructions and by a finite number of operator inputs which are made by the photographer via various switches described elsewhere herein that are a part of the system. Based upon the inputs received, the PLC  70  locks and unlocks the camera, coordinates operation of the lighting system with the operator of the camera, and causes various indicator lights to illuminate and, if all is not right and the photographer tries to take a picture, an audible alarm sounds. 
   The ultra-sonic indicator panel  72  includes two indicator lights, a green light  90  and a red light  92 . The lights are designed to operate individually or in combination to indicate certain conditions. Thus, if both lights are off, as at  94 , this indicates that the subject or subjects are not in proper position to be photographed, i.e., not on the pose line, etc. In this indicated condition, a synchronized camera will not be enabled and, if desired, a buzzer can be activated if an exposure is attempted. If the red light alone is on, this means that the main light  60  is not in the right position (up/down) to properly light the subject or subjects in the position they are sensed. If the green light  90  alone is illuminated, this indicates that insofar as the ultra-sonic indicator is concerned, it is permissible to take an exposure. 
   The main light control panel  74  also includes two indicator lights, namely, a green LED  100  and a larger push button with amber LED  102 . Illumination of the green light indicates that the main light is in a correct position on the track  50  and the correct modifier/baffle is in place on the main light. The up/down switch  64  is preferably a conventional micro-switch and the sensors  52 ,  54 ,  56  and  58  along track  50  may be proximity sensors or other conventional position sensing devices. Thus, an initial lighting ratio is established by the background sensed and the position of the main light sensed. Any modifiers (devices used in front of the light such as baffles) required for the main light can also be sensed. Correct settings are indicated by the illumination of the green light  100  which indicates the main light is in one of the four correct positions and the correct modifier has been applied. Conversely, if the green LED is off, this means that the main light is not in the correct position and/or a modifier should be put on or taken off. As was the case with the ultra-sonic sensor panel, a buzzer can be provided to sound if an exposure is attempted when the main light is not in a correct position on the track or if a modifier/baffle is required. If an exposure is attempted in any such situation, the camera and/or lights will not be enabled. 
   The larger amber button light  102  controls and indicates the use of an increased lighting ratio. Pressing this button will increase lighting ratio from the normal calculated by the system to an increased ratio (see  FIG. 5 ) and this will also illuminate the amber light. Conversely, when the button is not illuminated, the system is at the originally calculated normal lighting ratio for that type of exposure. 
   Control panel  76  includes an array of indicator lights and other devices. This includes three amber LED indicator lights  110 ,  112  and  114  as shown best in  FIG. 3   d . A red indicator light  116 , a hair light control button  118 , a buzzer device  120  and, if desired, a phone jack for a passport camera is shown at  122 . The three amber lights  110 ,  112  and  114  are used singularly and in combination to indicate, for example, which of the five different types of backgrounds is sensed. Thus, in one configuration, the lighting of indicator light  110  alone may be used to indicate a background sensed in position  1  by sensors  44  which would indicate a light background as per  FIG. 3   a . Likewise, illumination of indicator light  112  would indicate sensing at position  2  by sensors  46  which, in turn, indicates a white background. When indicator  114  alone is lit, this indicates sensing at position  3  only, which, in turn, indicates the presence of a gray background. With both lights  110  and  114  illuminated, as at  124 , this indicates background sensed by sensors  48  and  44  indicating background sensed in both positions  1  and  3  which would correspond to a black background. Finally, as shown at  126 , with indicator lights  110  and  112  illuminated, this indicates background sensed at positions  1  and  2  which corresponds to the sensing of other dark backgrounds. 
   Red light  116  may be designed to come on when the hair light is off and is extinguished when button  118  is used to turn the hair light on. The hair light is designed to return to a default or on state after five minutes and when this occurs. The buzzer  120  may be connected to sound in such case. 
     FIG. 4  is a table which lists common exposure problems encountered in studios of a class suitable for implementation with the system of the present invention. The table also lists the related effect on aperture opening or F-stop of each problem. To the right are listed corresponding exposure solutions implemented and the corresponding reduction in F-stop effect. Note that the adjustment of lights based on backgrounds, use of sonic sensors to detect the position of the subject and main light and light synchronization and delay alone reduce the total possible F-stop effect attributable to these causes alone from 1.28 to 0.1. Other factors have to do with the camera itself or operation of the camera and exposure meter. 
     FIG. 5  is a flash lighting ratio chart based on position of background types showing normal and increased flash lighting ratio settings based on those factors. The chart shows the alternate or increased settings available using button  102 . Position numbers refer to the position of the main light along the position rail  50 . These alternate or increased ratios have been shown to produce excellent results. 
     FIGS. 6   a - 6   e  are charts that show combinations of lighting settings for various backgrounds with the different main light positions including the use of normal increased and default flash lighting ratios. They include settings for main, fill, hair and background lighting under these conditions. Note that the numbers can vary significantly from the uncorrected or default readings. Thus, with the automatic control system on, the system will adjust each of the four lights and the four-light portrait lighting system with each light being controlled by the strobe power pack  24  which has the ability to control not only the on/off setting of the light, but also for adjusting the power level from, for example, 20 to 400 watt seconds. The strobe power pack  24  communicates with the PLC  70  through a serial control line  85  and synchronization is achieved via line  86 . The camera is synchronized via camera sync line  87 , which may indicate a tether or remote communication link. 
   In operation, the photographer first composes the scene by (a) positioning the subject or subjects to be photographed substantially along the position locator or pose line, (b) selecting a background and (c) positioning the main light up or down and at the desired main light position along the light track. With the automated control system activated, all the sensors will provide data to the programmable logic controller which, utilizing ladder programming, provides camera synchronization first and then synchronizes the strobe power pack. In this manner, the ultra-sonic indicator panel will confirm the correct subject position by illuminating the green LED. The general control panel will indicate the correct background having been sensed and the hair light can be activated, if desired. 
   Likewise, the main light control panel will indicate whether the main light is in the correct position and whether a correct modifier is in place. At this point, the lighting ratio can be increased if desired and camera sync established. Thereafter, the programmable delay assures that the strobe power pack is recycled and ready to fire and the serial line to the strobe power pack turns the channels off and on and sets the power levels for the four lights. This having been done, the exposure can be made. 
   This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself.