How does laser assisted auto-focus work?
On the focus assist systems I have seen the concept is actually very simple. A camera cannot focus in the dark. In dim light it may not focus quickly or well.
To compensate, cameras (or attached flash units) project a focus assist beam that is visible to the camera and may or may not be visible to people (it is sometimes infra red). Most assists project a light pattern, e.g., vertical bars like a short bar code, that works very well with the camera's focus system giving a very fast focus. The beam stops when the shutter is open so the image is unaffected.
Several cameras have had depth sensing capabilities. Focus on a near object then focus on a far object, run a calculation to obtain the optimal aperture needed to keep all objects in apparent focus (focus is absolute but a depth of acceptable focus can be obtained by reducing the lens aperture). Sweeping the focus beam across a scene and sampling distances would automate the process.
You can also improvise a laser assist by using a laser pointer, which actually gives greater range than the focus assists in cameras (generally under 10 meters).
To compensate, cameras (or attached flash units) project a focus assist beam that is visible to the camera and may or may not be visible to people (it is sometimes infra red). Most assists project a light pattern, e.g., vertical bars like a short bar code, that works very well with the camera's focus system giving a very fast focus. The beam stops when the shutter is open so the image is unaffected.
Several cameras have had depth sensing capabilities. Focus on a near object then focus on a far object, run a calculation to obtain the optimal aperture needed to keep all objects in apparent focus (focus is absolute but a depth of acceptable focus can be obtained by reducing the lens aperture). Sweeping the focus beam across a scene and sampling distances would automate the process.
You can also improvise a laser assist by using a laser pointer, which actually gives greater range than the focus assists in cameras (generally under 10 meters).
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