Method of automatically tracking and photographing celestial objects and photographic apparatus employing this method

A photographic apparatus which automatically tracks and photographs a celestial object which moves relative to said photographic apparatus due to diurnal motion so that an image of the celestial object that is formed on an imaging surface of an image sensor via a photographing optical system of said photographic apparatus becomes stationary relative to a predetermined imaging area of said image sensor during a celestial-object auto-tracking photographing operation, said photographic apparatus comprising:

• an inputter that inputs photographing azimuth angle information and photographing elevation angle information of said photographic apparatus which is directed toward the celestial object;
• a calculator that calculates first-tracking drive control data for performing a first-tracking photographing operation based on the photographing azimuth angle information and the photographing elevation angle information;
• a device that performs the first-tracking photographing operation, for a predetermined exposure time, based on the first-tracking drive control data;
• a device that obtains, after said first-tracking photographing operation based on said first-tracking drive control data finishes, a first preliminary image and a second preliminary image, wherein the first preliminary image corresponds to a commencement point of images taken by the first-tracking photographing operation and the second preliminary image corresponds to a termination point, that occurs upon lapse of the predetermined exposure time, of images taken by said first tracking photographing operation;
• a calculator that calculates an amount of deviation between a celestial object image in the first preliminary image and a corresponding celestial object image in the second preliminary image;
• a calculator that calculates, based on the amount of deviation, second-tracking drive control data for performing a second-tracking photographing operation with said deviation amount cancelled;
• a device that performs the second-tracking photographing operation based on the second-tracking drive control data;
• a judger that judges, in accordance with a comparison between said deviation amount and a predetermined threshold value, whether or not said first-tracking drive control data is to be corrected, and
• when it is judged that said first tracking drive control data is to be corrected, said first tracking drive control data is corrected with said deviation amount to calculate said second tracking drive control data.

A method of automatically tracking and photographing a celestial object which moves relative to a photographic apparatus due to diurnal motion so that an image of the celestial object that is formed on an imaging surface of an image sensor via a photographing optical system of the photographic apparatus becomes stationary relative to a predetermined imaging area of the image sensor during a celestial-object auto-tracking photographing operation, the method comprising:

• inputting azimuth information with respect to the photographic apparatus, of the celestial object;
• calculating first-tracking drive control data for performing a first-tracking photographing operation based on the azimuth information;
• performing the first-tracking photographing operation, during a predetermined exposure time, based on the first-tracking drive control data;
• obtaining, after said first-tracking photographing operation based on said first-tracking drive control data finishes, a first preliminary image, upon lapse of a predetermined time, and a second preliminary image, wherein the first preliminary image and the second preliminary image respectively correspond to a commencement point and a termination point of images taken by said first-tracking photographing operation;
• calculating an amount of deviation between a celestial object image in said first preliminary image and a corresponding celestial object image in said second preliminary image;
• calculating, based on the amount of deviation, second-tracking drive control data for performing a second-tracking photographing operation with the deviation amount cancelled,
• performing the second-tracking photographing operation based on the second-tracking drive control data;
• judging, in accordance with a comparison between the deviation amount and a predetermined threshold value, whether or not the first-tracking drive control data is to be corrected;
• and
• wherein said calculating of the second-tracking drive control data for performing said second-tracking photographing operation comprises correcting said first-tracking drive control data with said deviation amount to calculate said second-tracking drive control data.

A photographic apparatus which automatically tracks and photographs a celestial object which moves relative to a photographic apparatus due to diurnal motion so that an image of the celestial object that is formed on an imaging surface of an image sensor via a photographing optical system of the photographic apparatus becomes stationary relative to a predetermined imaging area of the image sensor during a celestial-object auto-tracking photographing operation, the photographic apparatus comprising:

• an inputter that inputs azimuth information of the celestial object with respect to the photographic apparatus;
• a device that performs the first-tracking photographing operation, during a predetermined exposure time, based on the first-tracking drive control data;
• a device that obtains, after said first-tracking photographing operation based on said first-tracking drive control data finishes, a first preliminary image and, upon lapse of a predetermined time, a second preliminary image wherein, the first preliminary image and the second preliminary image respectively correspond to a commencement point and a termination point of images taken by the first-tracking photographing operation;
• a calculator that calculates an amount of deviation between a celestial object image in the first preliminary image and a corresponding celestial object image in the second preliminary image;
• a calculator that calculates, based on the amount of deviation, second-tracking drive control data for performing a second-tracking photographing operation with the deviation amount cancelled,
• a device that performs the second-tracking photographing operation based on the second-tracking drive control data;
• and
• a device that judges, in accordance with a comparison between the deviation amount and a predetermined threshold value, whether or not the first-tracking drive control data is to be corrected,
• wherein said calculating of the second-tracking drive control data for performing said second-tracking photographing operation comprises correcting said first-tracking drive control data with said deviation amount to calculate said second-tracking drive control data.