Image sensing apparatus with exposure controller

An image sensing apparatus comprising:

• an image sensor which generates an electrical signal commensurate with an amount of incident light, and has a photoelectric conversion characteristic comprised of a linear characteristic area, where the electrical signal is outputted after being linearly converted in relation to the amount of incident light, and a logarithmic characteristic area, where the electrical signal is outputted after being logarithmically converted in relation to the amount of incident light;
• an exposure evaluation value detector configured to detect an exposure evaluation value based on luminance information acquired from a subject in sensing an image of the subject;
• and
• an exposure controller configured to acquire a setting value for exposure based on the exposure evaluation value detected by the exposure evaluation value detector to control exposure of the image sensing apparatus, the exposure controller including an exposure amount controller configured to control an exposure amount and a dynamic range controller configured to control the photoelectric conversion characteristic of the image sensor,
• wherein the exposure controller is configured to determine a subject luminance for exposure setting based on the exposure evaluation value, and is configured to control the exposure by using at least one of the exposure amount controller and the dynamic range controller such that an output of the image sensor corresponding to the subject luminance for exposure setting is obtained from the linear characteristic area of the photoelectric conversion characteristic of the image sensor,
• wherein the exposure evaluation value is detected, by the exposure evaluation value detector, each from a main subject image area, and a peripheral subject image area of an image sensing area of the image sensor,
• wherein the subject luminance for exposure setting is selected from the exposure evaluation value detected in the main subject image area;
• and
• wherein if the subject luminance for exposure setting is lower than a predetermined value, the exposure amount controller controls the exposure amount in combination with the control of the photoelectric conversion characteristic by the dynamic range controller.

An image sensing apparatus comprising:

• an image sensor which generates an electrical signal commensurate with an amount of incident light, and has a photoelectric conversion characteristic comprised of a linear characteristic area, where the electrical signal is outputted after being linearly converted in relation to the amount of incident light, and a logarithmic characteristic area, where the electrical signal is outputted after being logarithmically converted in relation to the amount of incident light:
• an exposure evaluation value detector configured to detect an exposure evaluation value based on luminance information acquired from a subject in sensing an image of the subject;
• and
• an exposure controller configured to acquire a setting value for exposure based on the exposure evaluation value detected by the exposure evaluation value detector to control exposure of the image sensing apparatus, the exposure controller including an exposure amount controller configured to control an exposure amount and a dynamic range controller configured to control the photoelectric conversion characteristic of the image sensor,
• wherein the exposure controller is configured to determine a subject luminance for exposure setting based on the exposure evaluation value, and is configured to control the exposure by using at least one of the exposure amount controller and the dynamic range controller such that an output of the image sensor corresponding to the subject luminance for exposure setting is obtained from the linear characteristic area of the photoelectric conversion characteristic of the image sensor,
• wherein the exposure controller further includes a photoelectric conversion characteristic information storage configured to store the photoelectric conversion characteristic of the image sensor acquired at the time of detecting the exposure evaluation value by the exposure evaluation value detector;
• and
• wherein if the subject luminance for exposure setting is lower than a predetermined value, the exposure amount controller controls the exposure amount in combination with the control of the photoelectric conversion characteristic by the dynamic range controller.