Flash photography system with preliminary and main emission
AssigneeCanon Kabushiki Kaisha
InventorsTatsuyuki Tokunaga, Yoichi Sato, Takao Takano
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Abstract
The present invention relates to a camera system which is arranged to find the amount of emission of a main emission on the basis of a measured light value obtained during a preliminary emission, and perform control of the main emission. More specifically, the present invention provides a camera system which is arranged to inhibit processing, such as abnormal-reflection correction, during execution of a specific kind of photography, such as bounce flash photography, perform control processing suited to the specific kind of photography, and execute correct amount-of-light control.
Claims44
A camera system arranged to cause a preliminary emission to be performed before a main emission is performed, and execute control of the main emission according to a result of light measurement performed during the preliminary emission, comprising:
- (a) a data forming circuit for forming control data for controlling an amount of emission of the main emission according to the result of the light measurement performed during the preliminary emission;
- (b) a control circuit for controlling the amount of emission of the main emission on the basis of the control data supplied from said data forming circuit;
- and
- (c) a correcting circuit for correcting the control data according to camera condition data, a state of a flash unit or the kind thereof or an operating state of the flash unit.
A camera system arranged to cause a preliminary emission to be performed before a main emission is performed, and execute control of the main emission according to a result of light measurement performed during the preliminary emission, comprising:
- (a) a light measuring circuit having a plurality of areas;
- (b) a data forming circuit for forming control data for controlling an amount of emission of the main emission according to a result of light measurement performed by said light measuring circuit during the preliminary emission;
- (c) a control circuit for controlling the amount of emission of the main emission on the basis of the control data supplied from said data forming circuit;
- and
- (d) a selecting circuit for selecting a measured light value for use in said data forming circuit from said plurality of areas according to camera condition data, a state of a flash unit or the kind thereof or an operating state of the flash unit.
A camera system comprising:
- (a) preliminary emission means for performing a preliminary emission pointed at a subject;
- (b) a light measuring circuit for measuring a light reflected from a subject during the preliminary emission, and for measuring a luminance of the subject while the preliminary emission is not being performed;
- (c) a measuring circuit for measuring an amount of emission of the preliminary emission through an optical path different from said light measuring circuit during the preliminary emission;
- (d) amount-of-main-emission computing means for computing a relative amount of emission of a main emission with respect to the amount of emission of the preliminary emission measured by said measuring circuit, on the basis of a measured light value obtained from said light measuring circuit;
- (e) backlight computing means for computing a backlighting condition of a main subject on the basis of a measured light value obtained from said light measuring circuit while the preliminary emission is not being performed;
- and
- (f) correcting means for applying a correction to a control value of the amount of emission of the main emission computed by said amount-of-main-emission computing means according to an output of said backlight computing means.
A camera system capable of controlling a flash unit, which is arranged to perform a main emission pointed at a subject and perform an exposure operation, comprising:
- (a) means for performing a preliminary emission pointed at a subject;
- (b) light measuring means for performing measurement of a light reflected from the subject during the preliminary emission;
- (c) computing means for computing an amount of emission of a main emission on the basis of a result of the measurement of the reflected light;
- (d) flash-unit control means for controlling the amount of emission of the main emission on the basis of a computation result provided by said computing means;
- and
- (e) a diaphragm setting circuit for setting a diaphragm of a photographing lens to a fully open aperture value before the preliminary emission.
A camera system capable of controlling a flash unit, which is arranged to perform a main emission pointed at a subject and perform an exposure operation, comprising:
- (a) means for performing a preliminary emission pointed at a subject;
- (b) light measuring means for performing measurement of a light reflected from the subject during the preliminary emission;
- (c) computing means for computing an amount of emission of a main emission on the basis of a result of the measurement of the reflected light;
- (d) flash-unit control means for controlling the amount of emission of the main emission on the basis of a computation result provided by said computing means;
- (e) a preliminary emission control circuit having a first mode for causing the preliminary emission to be performed immediately before the main emission and a second mode for causing the preliminary emission to be performed independently of a preliminary-emission operation;
- and
- (f) control means for causing said camera system to perform continuous shooting in the second mode while repeating the same amount of emission as an amount of emission for a first frame.
A camera system capable of controlling a flash unit, which is arranged to perform a main emission pointed at a subject and perform an exposure operation, comprising:
- (a) means for performing a preliminary emission pointed at a subject;
- (b) light measuring means for performing measurement of a light reflected from the subject during the preliminary emission;
- (c) computing means for computing an amount of emission of a main emission on the basis of a result of the measurement of the reflected light;
- (d) flash-unit control means for controlling the amount of emission of the main emission on the basis of a computation result provided by said computing means;
- (e) a preliminary emission control circuit having a first mode for causing the preliminary emission to be performed immediately before the main emission and a second mode for causing the preliminary emission to be performed independently of a preliminary-emission operation;
- and
- (f) detecting means for detecting whether a direction of an emission part of a flash unit has been changed;
- and
- (g) mode changing means for changing the second mode to the first mode if said detecting means detects that the direction of the emission part has been changed.
A camera system comprising:
- mode setting means for setting a photographing mode of a camera;
- flash means capable of performing a flat emission;
- and
- flash-unit control means for inhibiting photography using the flat emission if a predetermined photographing mode is set by said mode setting means.
A camera system capable of controlling a flash unit, which is arranged to perform a main emission, comprising:
- (a) a preliminary emission circuit for causing said flash unit to perform a preliminary emission;
- (b) a calculation circuit for calculating an amount of emission of the preliminary emission according to a photographing conditions;
- and
- (c) a determination circuit for determining an amount of emission of the main emission on the basis of a measured light output obtained during the preliminary emission.
Dependencies are inferred from the claim text.