Lens attachment for flash-light photographing

Abstract

In an automatic flash camera having a lens with a rotatable focusing ring, a lens attachment coacts with the focusing ring to control the camera. In the attachment, a mounting arrangement detachably mounts the attachment to the end of the lens. An interconnecting arrangement, rotatably mounted on the mounting arrangement, engages the focusing ring to move therewith. A variable resistance system is mounted on the two arrangements and is varied by movement of the interconnecting arrangement relative to the mounting arrangement. The variable resistance system includes an adjustable member which is movable between a number of positions. In one position the variable resistance system exhibits one range of resistances corresponding to one type of lens when the interconnecting arrangement is moved. In other positions the variable resistance system exhibits other ranges of resistances each corresponding to lenses of other aperture ratios and focal lengths. An electrical system connected to the variable resistance system responds to the value of the resistance exhibited and controls the diaphragm of the camera for automatic flashlight photography.

What is claimed: 
     
       1. For an automatic flash camera having an automatic diaphragm control and a photographic lens with a rotatable focusing ring, a lens attachment, comprising mounting means for detachably mounting the attachment at the end of the lens, interconnecting means rotatably mounted on said mounting means and engageable with the focusing ring, variable resistance means mounted on said mounting means and said interconnecting means, said resistance means being variable by movement of said interconnecting means with the focusing ring and having an adjustable member which is movable between a plurality of positions, said variable resistance means exhibiting one range of resistances corresponding to one type of lens when the member is in one position and the interconnecting means is moved relative to the mounting means through a given path, said variable resistance means exhibiting another range of resistances corresponding to another type of lens when the member is in another position and the interconnecting means is moved relative to the mounting means through a path corresponding to the one path, electrical means connected with said variable resistance means and coupled to said diaphragm control means for adjusting the diaphragm on the basis of an electrical resistance value based upon the rotation of the focusing ring and the position of said member, said member being adjustable to a position causing said resistance means to exhibit a range of values corresponding to the type of lens. 
     
     
       2. An attachment as in claim 1, wherein said variable resistance means includes a plurality of conductive contact means extending along a plurality of separate paths and mounted on one of said interconnecting means and said mounting means, said resistance means further including a slider mounted on the other of said mounting means and said interconnecting means and contacting one of said contact means on the basis of the position of said member and movable along one of the paths when said interconnecting means moves with respect to said mounting means and varying the resistance exhibited by said resistance means on the basis of the type of lens being used and the position of the focusing ring. 
     
     
       3. An attachment as in claim 1, wherein said variable resistance means extends along a circular path. 
     
     
       4. A system as in claim 2, wherein said resistor means extend along circular paths. 
     
     
       5. An attachment as in claim 2, wherein each of said contact means comprises an insulating base plate, a plurality of contact strips extending along the path, said strips being separated from each other, a plurality of resistances connected between said contact strips, the location of said contact strips causing said slider to be connected to different ones of said resistances depending upon the position of said member and the focusing of said ring, and wiring means connecting said resistance means to said circuit means. 
     
     
       6. A camera, comprising a camera body, an interchangeable lens, an adjustable focusing ring on the lens, mounting means for detachably mounting the attachment at the end of the lens, interconnecting means rotatably mounted on said mounting means and engageable with the focusing ring, variable resistance means mounted on said mounting means and said interconnecting means, said resistance means being variable by movement of said interconnecting means with the focusing ring and having an adjustable member which is movable between a plurality of positions, said variable resistance means exhibiting one range of resistances corresponding to one type of lens with the members in one position and the interconnecting means is moved relative to the mounting means, said variable resistance means exhibiting another range of resistances corresponding to another type of lens when the member is in another position and the interconnecting means is moved relative to the mounting means, electrical means connected with said variable resistance means and coupled to said diaphragm control means for adjusting the diaphragm on the basis of an electrical resistance value based upon the rotation of the focusing ring and the position of said member, said member being adjustable to a position cause said resistance means to exhibit a range of values corresponding to the type of lens. 
     
     
       7. A camera as in claim 6, wherein said variable resistance means includes a plurality of conductive contact means extending along a plurality of separate paths and mounted on one of said interconnecting means and said mounting means, said resistance means further including a slider mounted on the other of said mounting means and said interconnecting means and contacting one of said contact means on the basis of the position of said member and movable along one of the paths when said interconnecting means moves with respect to said mounting means so as to vary the resistance exhibited by said resistance means on the basis of the type of lens being used and the position of the focusing ring. 
     
     
       8. A camera as in claim 6, wherein said variable resistance means extends along a circular path. 
     
     
       9. A system as in claim 7, wherein said resistor means extend along circular paths. 
     
     
       10. A camera as in claim 7, wherein each of said resistor means comprises an insulating base plate, a plurality of contact strips extending along the path, said strips being separated from each other, a plurality of resistances connected between said contact strips, the location of said contact strips causing said slider to be connected to different ones of said resistances depending upon the position of said member and the focusing of said ring, and wiring means connecting said resistance means to said electrical means. .Iadd. 11. For a single lens reflex camera having an interchangeable lens with a maximum diaphragm aperture, diaphragm control means including electrical means and a photometric element coupleable to said electrical means for receiving light passing through the maximum aperture of the interchangeable lens, and correcting means for correcting variations in the measurements of the photometric element as a result of the particular maximum aperture of the interchangeable lens, an automatic flash control device comprising: information setting means connectable to the diaphragm control means for setting information for flash photography,   selector means for connecting said electrical means to one of the photometric elements and the information setting means in dependence upon whether the flash is to be used, and   removing means in said setting means for substantially removing the correction of the correcting means. .Iaddend. .Iadd. 12. An apparatus as in claim 11, wherein said setting means forms a part of an attachment removably mounted on said interchangeable lens, said setting means including variable resistance means connectable to said electrical means, said resistance means exhibiting an output resistance and having first resistance varying means for varying the resistance on the basis of manually entered flash information and second varying means for varying the resistance on the basis of the maximum aperture of the lens. .Iaddend..Iadd. 13. An automatic flash device for a single lens reflex camera having an interchangeable lens, a diaphragm control means including electrical means connectable to a photometric element which receives light passing through the full-opened diaphragm of the interchangeable lens, and a means for correcting errors in the photometry corresponding to the open diaphragm value of the interchangeable lens, said automatic flash photographing means comprising:   setting means connectable to the diaphragm control means for setting information for the flash photography   selector means for changing and connecting the photometric element and the information setting means to the electrical means in correspondence to daylight photography and flash photography, and   means for substantially removing the correction corresponding to the open diaphragm value of the interchange lens for the flash photography. .Iaddend. .Iadd. 14. The device according to claim 13 wherein said setting means form part of an attachment removably mounted on one end of the interchangeable lens, said attachment comprising a variable resistance means for setting the flash photography information, connectable to the electrical means and varying means for changing the correction made according to the open diaphragm value of the interchange lens correctly for performing a flash operation. .Iaddend..Iadd. 15. The device according to claim 14 in which the varying means includes a variable resistance and a contact means. .Iaddend. .Iadd. 16. The device according to claim 13 in which the electrical means includes an ammeter, and the correction means rotates the ammeter in correspondence to the open diaphragm value of the interchangeable lens. .Iaddend..Iadd. 17. An automatic flash device for a single lens reflex camera having an interchangeable lens, diaphragm control means including electrical means connectable to a photometric element which receives light passing through the full-opened diaphragm of the interchange lens, and means for correcting errors in the photometry corresponding to the open diaphragm value of the interchange lens, said automatic flash photographing device comprising:   information setting means for setting information for flash operation, connectable to the diaphragm control means,   a selector means for connecting the photometric element and the information setting means to the electrical means in correspondence to daylight photographing and flash photographing, and   a recorrecting means for recorrecting the previously made correction on the basis of the open diaphragm value of the interchangeable lens when the selector means is set for performing flash photography. .Iaddend..Iadd. 18. The device according to claim 17, wherein said setting means and recorrecting means form part of an attachment removably mounted on one end of the interchange lens. .Iaddend..Iadd. 19. For a single lens reflex camera with a body and one of a plurality of interchangeable lenses having a plurality of maximum apertures, a plurality of data entering means on at least one of said body and said lens, sensing means for sensing through the maximum aperture of the lens, operating means responsive to the maximum aperture of the lens and coupled to said sensing means for establishing at least an indication of the aperture to which the lens is to be set on the basis of said sensing means and varying it on the basis of the maximum aperture of the lens, a flash adjusting device, comprising:   setting means responsive to one of said entering means and coupleable to said operating means for constraining said operating means to establish an aperture;   switch means for disconnecting said sensing means from said operating means and connecting said setting means to said operating means;   said setting means including defeat means for defeating the variation in the aperture produced by said operating means in response to the changes in the maximum aperture of the lens. .Iaddend. .Iadd. 20. An apparatus as in claim 19, wherein said defeat means includes a plurality of resistance means and means for varying the resistance on the basis of the maximum aperture of the lens. .Iaddend..Iadd. 21. An apparatus as in claim 19, wherein said operating means includes an ammeter, and said ammeter is rotated on the basis of the maximum aperture of the lens. .Iaddend. .Iadd. 22. An apparatus as in claim 19, wherein said setting means includes an attachment removably mounted on one end of said interchangeable lens, said attachment including coupling means coupled to said entering means, and means for setting said defeat means to a particular setting corresponding to the maximum aperture to be defeated. .Iaddend..Iadd. 23. An apparatus as in claim 19, wherein said entering means is the focusing ring. .Iaddend. .Iadd. 24. An apparatus for adjusting the operation of an interchangeable-lens focus-adjustable single-lens-reflex flash camera, comprising setting means for establishing an aperture value on the basis of flash information, connector means for entering the information, said setting means including varying means for varying the flash information on the basis of the maximum aperture of the interchangeable lens being used. .Iaddend..Iadd. 25. A camera comprising a body, one of a plurality of interchangeable lenses having one of a plurality of maximum apertures, a plurality of entering means for entering information into said camera, sensing means in the path of light from the lens for producing an output responding to light striking the sensing means, control means responsive to said sensing means for establishing a value corresponding to the desired ambient-light aperture of the lens, setting means coupled to one of said entering means for setting a value corresponding to a desired flash aperture, a switching means for disconnecting said sensing means for said control means and connecting said setting means to said control means, said setting means having variable defeat means settable to a plurality of positions corresponding to one of the plurality of maximum apertures for varying the set value on the basis of the maximum aperture of the lens. .Iaddend.