An imaging device comprising: an imaging optical system that includes a first optical system and a second optical system having a common optical axis and having different focal lengths; an imaging element that includes a first sensor group selectively receiving light passing the first optical system and a second sensor group selectively receiving light passing the second optical system; and an image generating unit that generates a first generated image on the basis of a first captured image output from the first sensor group and generates a second generated image on the basis of a second captured image output from the second sensor group, characterized in that the image generating unit has an image compositing unit, wherein the image compositing unit generates the first generated image by performing registration on a plurality of the first captured images captured in different states of the optical axis of the first optical system and by compositing the registrated plurality of first captured images, and generates the second generated image by performing registration on a plurality of the second captured images captured in different states of the optical axis of the second optical system and by compositing the registrated plurality of second captured images, wherein the plurality of first captured images is captured in different states of a direction of the optical axis of the first optical system and output from the first sensor group, wherein the plurality of second captured images is captured in different states of a direction of the optical axis of the second optical system and output from the second sensor group, and wherein each of the registrated plurality of first captured images is calculated on a basis of following equation, and each of the registrated plurality of second captured images is calculated on a basis of following equation, Sw = k ⋅ fw ⋅ tan θ, St = k ⋅ ft ⋅ tan θ, wherein k represents a constant, fw represents the focal length of the first optical system, ft represents the focal length of the second optical system, θ represents the angle of a pan of the imaging device including the imaging optical system, Sw represents each of the amounts of movement of the plurality of the first captured images, and St represents each of the amounts of movement of the plurality of the second captured images. an imaging optical system that includes a first optical system and a second optical system having a common optical axis and having different focal lengths; an imaging element that includes a first sensor group selectively receiving light passing the first optical system and a second sensor group selectively receiving light passing the second optical system; and an image generating unit that generates a first generated image on the basis of a first captured image output from the first sensor group and generates a second generated image on the basis of a second captured image output from the second sensor group, characterized in that the image generating unit has an image compositing unit, wherein the image compositing unit generates the first generated image by performing registration on a plurality of the first captured images captured in different states of the optical axis of the first optical system and by compositing the registrated plurality of first captured images, and generates the second generated image by performing registration on a plurality of the second captured images captured in different states of the optical axis of the second optical system and by compositing the registrated plurality of second captured images, wherein the plurality of first captured images is captured in different states of a direction of the optical axis of the first optical system and output from the first sensor group, wherein the plurality of second captured images is captured in different states of a direction of the optical axis of the second optical system and output from the second sensor group, and wherein each of the registrated plurality of first captured images is calculated on a basis of following equation, and each of the registrated plurality of second captured images is calculated on a basis of following equation, Sw = k ⋅ fw ⋅ tan θ, St = k ⋅ ft ⋅ tan θ, wherein k represents a constant, fw represents the focal length of the first optical system, ft represents the focal length of the second optical system, θ represents the angle of a pan of the imaging device including the imaging optical system, Sw represents each of the amounts of movement of the plurality of the first captured images, and St represents each of the amounts of movement of the plurality of the second captured images.