Exposure control apparatus

Claim 2

In a camera of the type having adjustable diaphragm and shutter means, lens means which is selectively adjustable to one of a plurality of focal lengths and light responsive means for automatically controlling said diaphragm and shutter means to effect a photographic exposure according to a predetermined program, the improvement comprising: adjustable program control meaNs, operatively associated with said diaphragm and shutter means, for varying said predetermined program of photographic exposure; and means, operatively associated with said lens means and said program control means, for adjusting said program control means in response to adjustment of said lens means so as to provide a more optimum relationship between shutter speed and depth of field for a focal length selected for said lens means.

Claim 3

In a camera having lens means of variably selectable focal length and diaphragm and shutter apparatus adapted to be adjustable in accordance with the level of scene illumination intensity, apparatus to provide a balanced relationship between shutter speed and depth of field, comprising: light responsive circuit means, operatively associated with said diaphragm and shutter apparatus and including photosensitive means located to be exposed to scene illumination and having a parameter of predetermined variation with the level of illumination intensity impinging thereon, for adjusting said diaphragm to form an aperture size and for actuating said shutter to operate at a shutter speed in accordance with the value of said parameter over a range of illumination intensity; variable resistance means, electrically coupled with said photosensitive means so that variations thereof establish selectable predetermined variations of said parameter variations with illumination intensity, for establishing multiply selectable relationships between the size of said aperture, said shutter speed and the level of illumination intensity; and means, coupling said lens means and said resistance means, for varying the value of said resistance means when said focal length of said lens means is varied.

Claim 4

In a camera having lens means of variably selectable focal length and diaphragm and shutter apparatus adapted to be adjustable in accordance with the level of scene illumination intensity, apparatus to provide a balanced relationship between shutter speed and depth of field, comprising: light responsive circuit means, operatively associated with said diaphragm and shutter apparatus and including photosensitive means located to be exposed to scene illumination and having a parameter of predetermined variation with the level of illumination intensity impinging thereon, for adjusting said diaphragm to form an aperture size and for actuating said shutter to operate at a shutter speed in accordance with the value of said parameter over a range of illumination intensity; variable resistance means, electrically coupled with said photosensitive means so that variations thereof establish selectable predetermined variations of said parameter variations with illumination intensity, for establishing multiply selectable relationships between the size of said aperture, said shutter speed and the level of illumination intensity; and means, coupling said lens means and said resistance means, for varying the value of said resistance means when said focal length of said lens means is varied.

Claim 5

In a camera having lens means of selectably variable focal length and diaphragm and shutter means which are automatically adjustable in accordance with the level of scene illumination intensity, apparatus for automatically providing an improved relationship between shutter speed and depth of field for different selected focal lengths comprising: light responsive circuit means, operatively associated with said diaphragm and shutter means and including first and second photosensitive elements each having a parameter which varies with the intensity of illumination impinging thereon, for first adjusting said diaphragm means to form an exposure aperture in accordance with the value of said parameters and for actuating said shutter apparatus to operate to establish a shutter speed in accordance with the value of at least one of said parameters; attenuation means, cooperating with said diaphragm apparatus, for varying the amount of light received by said first photosensitive element in response to adjustment of said diaphragm apparatus; variable resistance means electrically coupled with said second photosensitive element, for affecting the parameter value thereof; and adjustment means, coupling said resistance means with said lens means, for varying said resistance means in response to variation of the focal length of said lens means.

Claim 6

In a camera having lens means of selectably variable focal length and diaphragm and shutter means which are automatically adjustable in accordance with the level of scene illumination intensity, apparatus for automatically providing an improved relationship between shutter speed and depth of field for different selected focal lengths comprising: light responsive circuit means, operatively associated with said diaphragm and shutter means and including first and second photosensitive elements each having a parameter which varies with the intensity of illumination impinging thereon, for first adjusting said diaphragm means to form an exposure aperture in accordance with the value of said parameters and for actuating said shutter apparatus to operate to establish a shutter speed in accordance with the value of at least one of said parameters; attenuation means, cooperating with said diaphragm apparatus, for varying the amount of light received by said first photosensitive element in response to adjustment of said diaphragm apparatus; variable resistance means electrically coupled with said second photosensitive element, for affecting the parameter value thereof; and adjustment means, coupling said resistance means with said lens means, for varying said resistance means in response to variation of the focal length of said lens means.

Claim 7

Apparatus as claimed in claim 3 in which said variable resistance means is series and shunt coupled with said second photosensitive element.

Claim 8

Apparatus as claimed in claim 3 including means for coupling said first and second photosensitive element during adjustment of said diaphragm means.

Claim 9

Apparatus as claimed in claim 5 wherein said means for coupling said first and second photosensitive means also electrically decouples said second photosensitive means from said light responsive circuit means when said apparatus provides shutter timing.