US2382617A - Method of photographically recording the order of passage of moving objects - Google Patents

Description

4 Sheets-Sheet 1 1945. L. DEL RICCIO METHOD OF PHOTOGRAPHICALLY RECORDING THE ORDER OF PASSAGE 0F MOVING OBJECTS Original Filed March 20, 1959 INVENTOR zaeEA/za aafilcc/o BY 740,4 MM

ATTORNEYS 1945. DEL RICCIO METHOD OF PHOTOGRAPHICALLY RECORDING THE ORDER OF PASSAGE OF MOVING OBJECTS Original Filed March 20, 1939 4 Sheets-Sheet 2 INVENTOR z oeENZo 0a i/cc/o ATTORNEY5 9/3 n i im 3 I E Q Aug. 14, 1945.

L. DEL RICCIO 2,382,617 METHOD OF PHOTOGRAPHICALLY RECORDING THE I ORDER OF PASSAGE OF MOVING QBJECTS Original Filed March 20, 1939 4 Sheets-Sheet 5 INVENTOR laeavzo 0E1 lF/cc/o A TTORNE 17.

1945- 1.. DEL RICCIO METHOD OF PHOTOGRAPHICALLY RECORDING THE JECTS 4 Sheets-Sheet 4 ORDER OF PASSAGE OF MOVING OB riginal Filed March 20, 1939 0 W m V J o W. 0 E w 5 W. J 1 Em ATTORNEYS Patented Aug. 14, 1945 UNITED STATES PATENT OFFICE I METnbD F PHOTZZiTZLLICALLYRCORD- ING THE ORDER OF PASSAGE OF MOVING OBJECTS Lorenzo del Bicclo, Los Angeles, Calif.

1943, Serial No. 489,424

6 Claims. (01. 95-5) This invention relates to a photographic method and has iorits chief object to provide a method, and means for carrying out the method, of making a photographic record of a succession of moving objects as they cross a given line so that said objects are piotorially represented on a sensitized surface in terms of the relative order and time in and at which they passed such line, this case being a division of my application, Serial Number 262,891, filed March 20, 1939, now Patent Number 2,320,350 issued June 1, 1943.

Said invention has for one of its purposes to provide a method for the accurate timing and judging of races of various types such as of runners, horses, automobiles and the like, whereby a continuous picture is obtained of all the contestants in the order in which they crossed the finish line and thus enable the judges and the spectators to visually, conveniently and accurately determine from said picture the result of such a con-test without the possibility of error that is attendant upon a judgment based upon visual perception of the actual contest itself,

particularly where the result is close.

The means heretofore used for that purpose have been high speed motion picture cameras -which are set up at one end of the finish line of a race track with the axis of its lens in the same vertical plane as the finish line, and as the competing horses, for instance, approach and cross the finish line, a series of intermittent exposures are made on a length of motion picture film from which the finish of the race could be reproduced at a convenient speed to enable the judges to decide the question as to the order in which the horses finished, or an enlargement could be made of the particular frame showing the leading horse directly on the finish line. Such cameras are, however,.in many respects unsuitable for that purpose, particularly since there is a space of time between successive individual pictures during which there is no record made of the position of the horses, which may be the precise moment in which the foremost horses crossed the finish line and the preceding and succeeding pictures may not correctly show their relative positions as determinative of the result in a cl race. Moreover, pictures taken with such a. c era may involve errors due to parallax, since a photograph of lines extending longitudinally of the camera will represent them as converging, and when the field of view of the camera is not confined to a single narrow strip of even width extending across the track in sub- Divlded and this application May 28,

for instance, may appear in the finished picture as ahead of or behind that of the horse nearest to the camera when in fact they may be both in line, or the horse who appears to be in ad- I vance of the other may in fact be behind him.

The camera used in the present invention, however, differs essentially from such motion picture cameras and has no such defect, for instead of photographing the finish oi the diilerent contestants intermittently on a series of successive individual frames, the camera used in the present invention continuously photographs on a travelling film only the passage of the contestants across the finish line, the field of exposure of the travelling film being limited to a very narrow line representing a field of view equivalent to little more than the finish line itself. Thus the resultant photograph shows the contestants strung out in the order in which each of them finished and separated from each other in the photograph a distance proportional to the time between their respective finishes.

A further object is to provide a method in which the same photographic record of such contests is simultaneously made upon two sensitive strips, one of which may be transparent film, from which prints and enlargements may be made or which may be developed into a reversed positive and projected on a large screen so that large numbers of attending spectators may view it, and the other a strip of photographic paper which may be developed into a reversed positive and examined by the judges in making their de cision with respect to the outcome of the contest, said strips being put through the developing process iimnediately at the end of each race. The film used may be ordinary black and white film, infra-red sensitive film when light conditions require it or color film for transparency projection.

Another object is to provide a method whereby the field of view photographed by said camera, when the camera is placed in its proper operating position where its optical axis is substantially in the same vertical plane as the finish line, is confined to a very narrow strip of substantially the same width throughout from the foreground adjacent the camera on, one side of the track to the background on the distant side of the track.

Another obiect is to provide a method whereby the pho raphic record made by said camera will incl de indicia to determine the line along which the camera was pointed and so furnish a check upon the correctness of the position which camera occupied with respect to the said finish line.

Still another object is to provide a method whereby the time at which each portion of the strips of sensitive material is exposed is photographicaily recorded upon each said portion, and thus show on the finished picture the actual time between the contestants as they crossed the finish line.

Many other objects and advantages oi the invention will appear from the following description of it taken in connection with the accompanying drawings in which:

Fig, l is a perspective view of a camera suitable for use in performing the method .of the invention.

Fig. 2 is a view on the line 22 of Fig. 1.

Fig. 3 is a viewon the line 3-4 of Fig. 2,

Fig. 4 is a view on the line 4-4 of Fig. 3.

Fig. 5 is a diagrammatic view of prisms within the camera for directing the entering rays towards the sensitive surfaces.

Fig. 6 is a shutter with its operating mechanism for opening either one of the lenses of the camera and closing the other.

Fig. '7 is a rotary shutter operated in connection with one of the lenses.

Fig. 8 is an adjustable mask whereby to regulate the size and shape of the exposure slit of the sensitive surfaces.

Fig. 9 is a diagrammatic view in perspective showing how the adJustable slit of Fig. 8 operates to obtain a uniform width of the field longitudinally of the camera.

Fig. 10 is another mask to be interposed in front of the sensitive surfaces.

Fig. 11 shows the image on a sensitive surface of a target placed in the field of the camera to determine in conjunction with the mask of Fig. 10 the position of the camera.

Fig. 12 is a strip of film made in accordance with the invention showing the finish line of a horse race and the order in which the horses finished and the time between them.

Fig. 13 is a disc bearing on its face a series of time notations.

Referring to the drawings, l is a light-proof camera box having mounted on the front board 2 thereof two lenses 3 and l disposed one above the other with their optical axes in the same vertical plane. 5 is a housing on top of the camera in which is contained a, time indicating device and its illuminating means, while mounted above it with its axis in the same vertical plane as the lenses 3 and l is a telescope sight 8 which may be provided with a fine wire stretched vertically across the center of its lens.

Lens 8 is used for photographing a field restricted to an extremely narrow strip of uniform width extending longitudinally of said lens and such as would constitute the finish line of a race, while lens 4 is used to photograph a target set up on an extension of the finish line across the track on which the race is run and thus check and determine the position of the camera with respect to said finish line as shown by the recorded image of the target on the sensitive surfaces. Said target may also hear legends indicating, for instance, the date and number of the race.

amen

I is a box-like supporting frame, preferably of a light metal such as aluminum, within the camera box, in and upon which is mounted various of the optical and mechanical elements of the camera. Slidably mounted within the camera box behind the lenses I and l is a shutter 8 provided with an aperture l. II is a pivoted lever having a slot ll engaging a pin it on said shutter. The other end of said pivoted lever is connected by the link II to the armature ll of a solenoid ll mounted on the frame I. I0 is a coil spring attached to the lever ill tending to hold the said shutter in one position where the aperture 8 is in register with the lens t while at the same time the shutter covers the lens 3. when an electric current controlled by a switch (not shown) is allowed to travel through the winding of the solenoid ii, the armature I4 is retracted and said shutter is moved by the lever l0 against the tension of the coil spring ii to a position where the lens 4 is closed and one end of the shutter has passed beyond the lens I thus opening it.

Mounted within the frame I and extending from the lens 3 to the film aperture I1 is a light tube i8 through which the rays entering by the lens I are confined in their passage to the surface of a travelling film I! immediately behind said aperture, which film during the photographing is driven in a direction lateral of said lens 3 ,and approximately at the same speed and in the same direction as the image of, for example, a horse which is moving across the field of the lens 3. A branch 20 from said light tube extends at right angles vertically to an aperture 24, similar in all respect to the aperture I l and behind which there is a travelling strip of sensitized paper 12. Positioned within said light tube l8 where the branch 20 Joins the main tube are a pair of right angle triangular prisms 23 and 24 having their diagonal faces cemented together, so that a beam of light entering by the lens 3 is split, one part passing directly through said prisms towards the aperture l1 and the other part being reflected at right angles towards the aperture 21. Thus a view photographed through the lens 3 is simultaneously registered upon both the film I 0 and the paper strip 22.

The apertures I1 and II are each in the form of a very narrow slit, extending transversely across the film and paper strip respectively. and are composed of two thin plates 25 and 28 having their opposite edges parallel. The plate 25 is fixed rigidly with its vertical edge on the optical axis of the lens 3, as the said axis extends to said apertures, while the plate 28 is slidable so that the width 01' the slit is adjusable. Moreover, the plate 26 has pivotally mounted upon its surface adjacent one edge a supplemental plate 21 whereby the adjustable edge of the slit may be disposed at an angle so that the width of the slit may be decreased along its length. The reason for the width and shape of the slit being made adjustable is that since the field of view of the lens 3 is to be limited to a very narrow line of uniform width extending longitudinally of the camera, the width of the closer to the camera, the pivoted plate may be adjusted so as to narrow the slit towards that edge of the film where the image of the more distant points'along the finish line will fall. The width of the slit will vary with the position of the camera, as, for instance, its distance from the track, the width of the track, and other circumstances. In any case, its width will be as narrow as possible consistent with a proper exposure of the traveling film or paper strip behind it.

This is illustrated in Fig. 9 in which the finish line is marked a and the field of view to be covered by the camera lens L is to be limited to a narrow strip of uniform width bounded by the vertical planes defined by the lines a and a on one side and the lines b and b on the other. It

will be seen that if the width of the exposure area of the film is that defined by the two parallel vertical lines a: and y, the image projected by the lens L will be that of the field included within the vertical planes aa' and c--c'; whereas by inclining the edge of the slit towards the end thereof which will receive the image of the background as shown by the line 2, the portion of the field lying between the vertical planes b-b' and -0 will be excluded from registering on a sensitive surface behind the aperture. In other words, let the finish line'be represented by a and let b. a short distance to one side of a and parallel thereto, define the width of a narrow band of uniform width extending across a racetrack, the beginning and end of said band, together with the lines a and b, forming a long, narrow rectangle. With the camera arranged so that the line a is in the same vertical plane with the optical axis of the lens L, the distance between a and b at the end nearest the lens would be represented by the l ne 1), the length of the line a by y, and the distance between a and b at the end further removed from the lens L would be represented by the line in, which is much shorter than 12 due to the fact that it is at a much greater distance from the lens L. Consequently, the line b will be projected as the line 2. Since the slit is to permit exposure only of the image of said uniform band between the lines a and b, the edge of the slit represented by the line z will be disposed at an angle to the line y. If the vertical edges of the slit were parallel as represented by a: and y, the slit would permit exposure of a constantly diverging band defined by the lines a. and c.

Mounted Within. the frame I and extending from the lens 4 to a second aperture 28 for the paper strip 22 is a light tube 29 through which the rays entering by the lens 4 are confined in their passage to the surface of the travelling paper strip 22. The aperture 28 is located a short distance beyond the aperture 2| in the line of travel of said paper strip. Said light tube is bent at right angles twice along its length in accordance with the path of said ray-s as directed by the prisms mounted within it and has a branch 38 extending horizontally to an aperture 3| for the film i9 similar to the aperture 28 and located somewhat beyond said aperture IT in the line of travel of said film. Said apertures 28 and 3| are each provided with a mask 32 in the form, for instance, of a pointer 32 which is so located in the aperture that when the optical axis of the lens 3 is in the same vertical plane with the finish line, the apex of the pointer portion 33 of a target 34 erected at the other end of said finish line across the track and the apex of said pointer of the mask 32 will coincide, as shown in Fig. 11, and will so appear on the developed film and paper strip exposed behind said apertures 3| and 28.

The travel of the film l9 and the paper strip 22 past the apertures 3| and 28' is intermittent and during their rest periods said film and paper strip are exposed to the light entering by the lens 4 by the rotating shutter mounted on the frame I and having therein an opening 4| for intermittently permitting the light entering by the lens 4 to be transmitted to said apertures 28 and 3|. Said shutter 40 is so mounted as to cut across the light tube 29 in a slot therein provided for that purpose.

It is of course understood that the planes of the travelling film l9 past the apertures l1 and 3| and of the travelling paper strip past the apertures 2| and 28 are the focal planes of the lenses 3 and 4.

Said film I9 and paper strip 22 are held secure.- ly in their respective positions immediately behind the apertures II and 3|, and 2| and 28, in the focal planes of the lenses 3 and 4, respectively, in each case by pressure plates 42 actuated by the flat springs 43. The pressure of said fiat springs 43 is adjustable by means of the nuts 43 on the threaded studs 44 so as to permit just sufficient pressure to be applied to the film I9 and the paper strip 22 to hold them accurately in their said positions and at the same time permit them to be drawn freely across said apertures.

Located within the housing 2 on the top of the camera box is an electric clock preferably of the type having a motor driven by alternating current of controlled frequency and comprising a field electromagnet 45 and a permanent magnet armature 46 which is caused to rotate in step with the alternations of the electric current. Connected to said armature by suitable gearing is the rotating disc 4! bearing on its face notations of time in terms, for example, of V of a second. Mounted on the other face of said disc immediately opposite each of said time notations is a series of switch points 48 adapted to make contact successively with the stationary contact spring 49 and thus close an electric circuit which includes a suitable source of current 50 and an electric lamp 5|, preferably a neon lamp, so that as the disc 41 rotates the successive time notations thereon are illuminated by the intermita tent flashing of the lamp 5| whose beams are directed towards said time notations by the condenser 52. 53 is a lens whereby beams of light corresponding to the successive images of the said time notations are projected downward into the camera box through the light tube 54 to the reflecting prism 55 from which they are reflected at right angles to the pair of prisms 23 and 24 and are there split and caused to fall upon both the film I9 and paper strip 22 through the slits l1 and 2| near the wider end of said slits which will correspond to the bottom of the finished picture. The diagonal face of the prism 55 is silvered or otherwise rendered opaque and thereby prevents the image projected by the lens 3 from falling upon the marginal portion of the film l9 and the paper strip 22 which is to receive the images of the said time notations.

The speed of the said clock motor and the sizes I and arrangement of the gears by which the disc thereon in accordance with the time indicated thereby and the speed of rotation of said disc.

The film I! is preferably standard 35 mm. motion picture film, although it may be of any convenient width, and is caused to travel from a supply reel in a light proof housing 86 continuously past the slit l'l by means of the sprocket ll and intermittently past the aperture Si by the sprocket ll after which it is fed continuously by the sprocket is either to a take-up reel located in the lightproof housing MI and driven by the belt II from a pulley on the shaft of the sprocket H, or directly into a developing tank or machine installed near the camera. Idle pressure rollers 82, 83 and 64 cooperate with the sprockets I1, BI and Us to hold the film is on said sprockets.

The paper strip 22 is preferably of the same size as the film II and provided with sprocket holes. It is caused to travel in the same manner and in the same direction and at the same speed as the film is from a supply reel in a lightprodf housing 65 continuously past the slit 2| by means of the sprocket 80 and intermittently past the aperture 28 by the sprocket 61 after which it is fed continuously by the sprocket 88 either to a take-up reel located in the lightproof houstical shaft I00, carrying the film sprocket I1, by means of a pair of bevel gears HH and 102 attached to the addacent ends of the shafts 98 and m respectively,

The speed of travel of both the film i! and the paper strip 22 from their respective supply reels past their respective apertures for best pictorial results should be approximately the same as the speed of the images of the horses or other contestants past the slits i1 and 2|, and it has been found by experiment that all of the said sprockets may be of the same size and rotate at v the same number of revolutions per minute, since ing is and driven by the belt Hi from a pulley on the shaft of the sprocket 3!, or, in the same way as the film ll, directly into a developing tank or machine. Idle pressure rollers 62', 83' and 64' cooperate with the sprockets 68, 81 and 68 to hold the paper strip 22 on said sprockets.

The rotation of the sprockets 51, 58, 59, I8, 81 and II, as well as the rotary shutter 40 is effected by the electric motor 10' which is mounted on a suitable base II within the camera box I. On the end of the armature shaft of said motor 10 towards the front of the camera is mounted a locking disc 12 and a crank arm 13 provided with a driving pin I4 engaging with the star-wheel 1!, thus providing a Geneva movement for the intermittent rotation of the vertical shaft I6 through a pair of spiral gears 11 and II attached to said stab-wheel I! and shaft I8 respectively. Said shaft carries the film sprocket II and at its upper end a bevel gear l0 meshes with the bevel gear 8| attached to one end of the shaft which carries the paper strip sprocket II. The relative sizes of the aforesaid gears is such that the film and paper strip are each advanced the distance of one frame with each revolution of the armature shaft of the motor 10', and held at rest while an exposure is made by the synchronous rotation of the rotary shutter Ill. The rotary shutter is operatlveLv connected to the front end of the armature shaft of the motor 10' by means of the bevel gears 82 and 83, the shaft 84 and the bevel gears II and II.

The continuous drive for the film sprockets I1 and I! and for the paper strip sprockets O6 and I8 is taken from the other and rear end of the armature shaft of the motor I0 to which is operatively connected by a pair of spiral gears 81 and II the vertical shaft 80 which carries the film sprocket ll. Said shaft at its upper end is operatively connected to the horizontal shaft 90 by a pair of bevel gears ll and 32 attached to adjacent ends of the shafts ll and 90 respectively. Said shaft carries the paper strip sprocket l8 and is provided at its front end with the bevel gear 98 meshing with the bevel gear 04 on the end of the shaft 08 which through the bevel gears GI and I1 drives the shaft 08. Said shaft ll carries the paper strip sprocket 8i, and drives the verthe variation in such speed of the film II and paper strip 22 past the slits l1 and II as called for by the speed of a slower type of contestants such as runners, for example, and a, faster type of contestants, such as automobiles, for example, will not affect the exposure at the apertures ll and 28 beyond. the ordinary range of adjustment of the stop opening of the lens 4 to correct it, or the setting of the rheostat I" which controls the speed of the motor 10' may be changed when exposing through the lens 4 to give the proper exposure at the apertures 3| and 28 since there is no movement of the target which is photographed through said apertures II and 28.

To make a photographic record of the finish of a horse race, for example, in accordance with the invention, the camera, suitably threaded with a supply of sensitive film and paper strip, is rigidly mounted on a suitable immovable support on one side of the track at the finish line and at a height slightly above that of the horses and pointed at a, slight angle downward so as to embrace a view of all the horses and to avoid the view of one horse being occluded by another horse closer to the camera. The side of'the track on which the camera is to be placed will be determined by the direction in which the race is run, since it is necessary that the travel of the film and paper strip be in the opposite direction. The camera is so positioned that the optical axes of its lenses 3 and l are at right angles to the course of said track and that the vertical plane of said axes intersect the apex of the pointer 88 of the target 34 which is positioned at the end of the finish line on the other side of the track. Such position of the camera can be readily determined by means of the telescope sight 8 whose optical axis is in the same vertical plane as those of the lenses I and 4. If desired, the telescope sight I may be dispensed with and the image of the target viewed on the back of the film l9 behind the aperture ll through an opening I i in the back of the camera provided for that purpose, the pressure plate 32 behind the aperture Ii having been temporarily removed for that purpose and the position of the camera adjusted until the apex of the pointer 33 coincides with the apex of the pointer of the mask 32. In this position the fixed edge of the slit il formed by'the plate II is in the vertical plane of the finish line and the width of the slit extends therefrom in the same direction as the travel of the film i9 and the paper strip 22. The said slit is then adjusted to the desired width and the angular adjustment of the opposite edge is made so as to confine the exposure area of the film and the paper strip to the image of a narrow band of uniform width across the track. The extent of such angular adjustment may be determined by calculation or by viewing the image of the field on the back of the film behind said slit and may be performed manually within the camera. The slit II is similarly A short time before the end of the race, mi-

, instance, when the horses are coming into the homestretch, the electric motor and the electric clock which are connected to a suitable source of electric current are put inoperation and a number of photographs made of the target is on the vtravelling film and paper strip through the apertures 3| and 28, thereby making a photographic record of the position ofthe camera with respect to said target and authenticating the fact that the subsequent exposures made on said film and paper strip through the slits l1 and 2| with the camera in the position in-which it was set represent what took place exactly at the finish line. 1

As the horses approach the finish line a currentof electricity is switched through the solenoid It thus causing the shutter 8 to be moved and held in the position where the lens 4 is closed and the lens 3 is open. It is understood that the speed of the motor has been adjusted by the rheostat I03 so that the film l9 and paper strip 22 are travelling past the slits l1 and 2| at the estimated speed at which the images of the horses will cross said slits when said horses cross, the finish line, and then as the horses do cross the finish line the images of them will be registered filmorpaperstripistraveliingmoreslowlythan thsimagesoi'thehorses,itwillresultinshorteningthelengthoitheplcturesoisaidhorseabin therelativepositionotsaid horsesandthedistanceintermsoithetimebetweentheminthe picture will not be thereby afiected.

upon the travelling film l9 and paper strip 22 in the relative order and time in which each said horse crossed the finish line. At the same time, while the film l9 and paper strip 22 are travelling past the slits I! and 2|, the intervals of time shown by the notations on the clock driven disc 41 are photographed on the said film and paper strip through said slits and will appear in the finished picture along the lower margin thereof. Thus the finished picture will show not only the relative order in which the horses finished, but also the difference in time between them. Such a picture is shown in Fig. 12.

It will be noted that the picture thus produced will be characterized by the absence from it of all objects or figures within the field of view of the camera lens, other than the horses themselves and their respective jockeys. Because of the continuous movement of the film and paper strip, each of the fixed objects such as the track itself, structures, the. target 3'4, etc., and background scenery, will not be defined or appear as such in the picture but will be present only as a, formless area of a gray tone corresponding to its light intensity, extending throughout the length of the picture, while the horses whose images are moving with the film and paper strip will appear thereon in distinct form. This serves to emphasize the definition of the images of the horses so that they stand out distinctly and their relative positions are easily determined by the eye free from any confusion with images of surrounding objects.

'While it is desirable that the speed of the travelling film and paper strip should be the same as that of the images of the horses as they travel across the slits in the direction of the-travelling film and paper strip, it is not essential that their respective speeds be exactly the same. If the film andpaper strip should be travelling faster than the images of the horses, it will only result in distorting the picture of the horses along their length by elongating their appearance and if the Immediately aiterthe last horse has crossed the finish line, the solenoid circuit is opened whereby the shutter I is retracted by the spring it to its former position, and, as the camera continues to run for ashort period, a number of successive photographs are again made of the target 34 through the lens 4 thus forming at the end of the race, as well as at the beginning, a satisfactory check upon the correctness of the position of the camera in recording the passage of the horses past the finish line and providing on the film and paper strip a notation of the date and number of the race or any other data appearing on the target.

Either the film Is or the paper strip 22 or both of them are then immediately developed, preferably to produce a reversed positive, from which the Judges of the race can easily determine the order in which the horses crossed the finish line and the interval of time between them, and the film may be projected one large screen to be viewed by the spectators. There may be a time, however, when the race is so close that the extension of the nose of one horse beyond the other is hardly discernible by the unaided eye, and as an aid for the accurate determination of such a question, the slits l1 and 2| may be bridged near one end thereof by a thin opaque strip I04 adjacent said end of the slits and at right angles thereto, which will have the effect of producing in the finished positive picture. a thin black line I05 extending longitudinally along said film and paper strip from which a vertical line representing the finish line may be erected by means, for instance, of a tri-square whereby the determination may be accurately and definitely made as to the nose of which horse occupies the more advanced position on said picture and which was therefore the first to cross the finish line. Obviously the specific details of my invention as illustrated and described may be varied in many respects without departing from the invention as defined in the appended claims.

What I claim is:

l. The method of making a photographic record of contestants crossing a finish line of a race upon a course, which comprises the steps of positioning a photographic camera to one side of and above said course with the optical axis of its objective in alignment with said finish line, continuously projecting through said objective the images of said contestants upon a light sensitive surface in said camera and at the same time moving said sensitive surface in the same direction and at substantially the same speed as said images and masking the said sensitive surface so that the area of exposure thereof is continuously confined to a narrow strip extending transversely of the direction of movement of said sensitive surface which is in optical correspondence with the said finish line and an area or said course adjoining said finish line on only one side thereof.

2. The method of making a photographic record of contestants crossing a finish line of a race upon a course, which comprises the steps of positioning a photographic camera to one side of and above said course with the optical axis oi its ob- .Iective in alignment with said finish line, continuously projecting through said objective the suri'aceinsaid cameraandatthesametimemoving said sensitive surface in the-same direction andatsubstantiailythesamespeedassaidimages and maintaining a masking element in front of said sensitive surface having an exposure apertureintheformofanarrowslitextendingtransversely of the direction of movement of said sensitive surface, and aligning one side edge of said exposure aperture with the optical axis of said objective and with said finish line so that the area of exposure of said sensitive surface is continuoua'ly confined to a narrow strip extending transversely of the direction of movement of said sensitive surface which is inoptical correspondencewiththesaidfinishlineandanareaofsaid course adjoining said finish line on only one side thereof. A

8. The method of making a photographic record ofcontestantscrossingafinishlineofarace upon a course, which comprises the steps of positioning a photographic camera to one side of and above said course with the optical axis of its objective in alignment with said finish line, continuousl projecting through said objective the images of said contestants upon a light sensitive surface in said camera and at the same time moving said sensitive surface in the same direction and at substantially the same speed as said images and masking the said sensitive surface so that the area of exposure thereof is continuously confined to a narrow, tapered strip extending transversely of the direction of movement of said sensitive surface which is in optical correspondence with a narrow vertical zone extending across said course, constituted on one side by said finish line and on the opposite side by a line parallel thereto and slightly spaced therefrom, the narrow part of said tapered exposed strip corresponding to the far end of said zone.

4. The method of making a photographic record of contestants crossing a finish line of a race upon a course, which comprises the steps of position'ing a photographic camera to one side of and above said course with the optical axis of its objective in alignment with said finish line, continously projecting through said objective the images of said contestants upon a light sensitive surface in said camera and at the same time moving said sensitive surface in the same direction and at substantially the same speed as said images and masking the said sensitive surface so that the area of exposure thereof is continuously confined to a narrow, tapered strip extending transversely of the direction of movement of said sensitive surface, one side of which strip coincides with the said finish line and the optical axis of said objective and the opposite side is at an angle to said first side and coincides with a line parallel to and slightly spaced from said finish line, the narrow images or said contestants upon a light sensitive partofsdd-taperedstripcorrespondingtotbefar endofsaidacne.

uponacourse,whichcomprisesthestepsofpositioning a photographic camera to one above said course with the optical axis of its jective in alignment with said finish line, uously projecting through said objective ages of said contestants upon a light surface in said camera and at the same moving said sensitive surface in the same tionandatsubstantiallythesames'peedassai images and maintaining a masking element in pered slit, extending transversely of the direction of movement of said sensitive surface, aligning one side edge of said slit with the said finish line and the optical axis of said objective and aligning the opposite side of said slit with a line parallel to and slightly spaced from said finish line whereby the exposure area of said sensitive surface will optically correspond to the narrow vertical none across the course between said finish line and said line parallel thereto, the narrow part of said tapered aperture slit corresponding to the far end of said zone.

6. The method of making a continuous still photographic record of contestants crossing a finish line of a race upon a course, which comprises positioning a photographic camera to one side of and above said course with the optical axis of the objective of said camera in alignment with said finish line, focusing said objective upon said finish line, continuously moving a light sensitive surface in said camera at substantially the same speed and direction as the speed and direction of movement respectively of the images of said contestants projected by said objective and at the same time maintaining a masking element in front of said sensitive surface having an exposure aperture in the form of a narrow tapered slit extending transversely of the direction of movement of said surface, aligning one side edge of said aperture slit with the said finish line and the other side edge with a line parallel to and slightly spaced from said finish line so that only the images of said contestants contained within the narrow vertical zone lying between the vertical plane including said finish line and the vertical plane including said line parallel thereto will be projected upon the exposed area of said sensitive mace and continuously photographing the contestants through said objective and exposure aperture of said masking element upon said sensitive surface as such contestants enter and remain in said narrow vertical zone.

LORENZO DIL RICCIO.

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