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US 2021/0278641 A1Published application
Attachment optical system, optical system, manufacturing method of optical system
AssigneeCanon Kabushiki Kaisha
InventorYoshiyuki Taki
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Abstract
An attachment optical system includes a first converter optical system attachable to an object side of an imaging optical system, and a second converter optical system attachable to an image side of the imaging optical system. The first converter optical system includes a dome-shaped cover and at least one positive lens. A predetermined condition is satisfied.
Claims11
An attachment optical system comprising:
- a first converter optical system attachable to an object side of an imaging optical system;
- and
- a second converter optical system attachable to an image side of the imaging optical system,
- wherein the first converter optical system includes a dome-shaped cover and at least one positive lens, and
- wherein the following conditional expression is satisfied:
- 0.00<|fd/ffc|<0.50
- where fd is a focal length of the dome-shaped cover in water, and ffc is a focal length of the at least one positive lens.
4 more elements
An optical system comprising:
- an imaging optical system;
- and
- an attachment optical system,
- wherein the attachment optical system includes:
- a first converter optical system attachable to an object side of an imaging optical system;
- and
- a second converter optical system attachable to an image side of the imaging optical system,
- wherein the first converter optical system includes a dome-shaped cover and at least one positive lens, and
- wherein the following conditional expression is satisfied:
- 0.00<|fd/ffc|<0.50
- where fd is a focal length of the dome-shaped cover in water, and ffc is a focal length of the at least one positive lens.
8 more elements
A manufacturing method of an optical system comprising the steps of:
- attaching at least one positive lens in a first converter optical system to an object side of an imaging optical system;
- attaching a second converter optical system to an image side of the imaging optical system;
- and
- attaching a dome-shaped cover in the first converter optical system to the object side of the imaging optical system,
- wherein the following conditional expression is satisfied:
- 0.0<|fd/ffc|<0.5
- where fd is a focal length of the dome-shaped cover in water, and ffc is a focal length of the at least one positive lens.
4 more elements
Dependencies are inferred from the claim text.