Focus detection apparatus and control method for the same
A focus detection unit detects a defocus value, and a correction value for shifting an in-focus position based on the defocus value is obtained by a first method or by a second method. The correction value obtained by the second method is converted to a correction value of the first method by changing units, and the correction value obtained by the first method or the converted correction value is stored in a storage unit. A control unit controls driving of a focus lens to a lens position based on a value obtained by correcting the defocus value by the stored correction value. In the second method, a user selects one of a plurality of images obtained by driving the focus lens, and the correction value is calculated based on the defocus value of the selected image.
1. A focus detection apparatus comprising at least one processor or one circuitry which functions as:
a focus detection unit that detects a defocus value;
a first calculation unit that obtains a correction value for shifting an in-focus position by a first method, the in-focus position being based on the defocus value;
a second calculation unit that obtains a correction value for shifting the in-focus position by a second method that is different from the first method, the in-focus position being based on the defocus value;
a conversion unit that converts the correction value obtained by the second method to a correction value of the first method by changing units;
a storage unit that stores the correction value obtained by the first calculation unit or the correction value converted by the conversion unit; and
a control unit that controls driving of a focus lens to a lens position based an a value obtained by correcting the defocus value by the correction value stored in the storage unit,
wherein, in the second method, at least one of a plurality of images obtained by driving the focus lens to a plurality of different lens position is selected by a user, and the correction value is calculated based on the defocus value corresponding to the selected image.
2. The focus detection apparatus according to claim 1 , wherein the processor or circuitry further functions as a selection unit that selects the first calculation unit or the second calculation unit,
wherein the storage unit stores the correction value obtained by the first calculation unit or the correction value converted by the conversion unit in accordance with a selection by the selection unit.
3. The focus detection apparatus according to claim 1 , wherein, in the second method, imaging is performed at respective lens positions of the focus lens while driving the focus lens by a predetermined driving step within a range predetermined on the basis of the in-focus position.
4. The focus detection apparatus according to claim 1 , wherein, in the second method, each image is stored in association with a defocus value, at least one of the plurality of stored images is selected by the user, and the correction value is calculated based on the defocus value of the selected image.
5. The focus detection apparatus according to claim 1 , wherein, in the first method, a shift amount of the focus lens to be shifted from the in-focus position is set by the user, and the on value is calculated based on the set shift amount.
6. The focus detection apparatus according to claim 5 , further comprising a display that displays a setting screen for the user to set the shift amount of the focus lens,
wherein the correction value stored in the storage unit is displayed on the setting screen.
7. The focus detection apparatus according to claim 1 , wherein, when a full-open F number of an imaging lens is F, a diameter of a permissible circle of confusion is δ, then a unit of the correction value in the first method is
( 1/16)*Fδ.
8. A control method for a focus detection apparatus comprising:
detecting a defocus value;
obtaining a correction value for shifting an in-focus position by a first method or by a second method that is different from the first method, the in-focus position being based on the defocus value;
converting, in a case where the correction value is obtained by the second method, the obtained correction value to a correction value of the first method by changing units;
storing the correction value obtained by the first method or the correction value converted in the converting step in a storage unit; and
controlling driving of a focus lens to a lens position based on a value obtained by correcting the defocus value by the correction value stored in the storage unit,
wherein, in the second method, at least one of a plurality of images obtained by driving the focus lens to a plurality of different lexis position is selected by a user, and the correction value is calculated based on the defocus value corresponding to the elected image.
9. A non-statutory computer-readable storage medium storing a program for causing a computer included in an image capturing apparatus to execute the steps of a control method that comprises:
detecting a defocus value;
obtaining a correction value for shifting an in-focus position by a first method or by a second method that is different from the first method, the in-focus position being based on the defocus value;
converting, in a case where the correction value is obtained by the second method, the obtained correction value to a correction value of the first method by changing units;
storing the correction value obtained by the first method or the correction value converted in the converting step in a storage unit; and
controlling driving of a focus lens to a lens position based on a value obtained by correcting the defocus value by the correction value stored in the storage unit,
wherein, in the second method, at least one of a plurality of images obtained by driving the focus lens to a plurality of different lens position is selected by a user, and the correction value is calculated based on the defocus value corresponding to the selected image.