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rem2722
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Say we define Depth of Field, DOF, as max de-focus allowed for decent Fraunhofer Pattern. Then what's the DOF of a (positive) lens with focal length f?
Depth of Field is the distance range within a scene that appears acceptably sharp in an image. It is controlled by the aperture, focal length, and distance between the subject and the camera.
Fraunhofer Pattern is a diffraction pattern that is produced when light passes through a narrow slit. In order to accurately capture and analyze this pattern, a sufficient DOF is needed to ensure that all elements of the pattern are in focus.
The DOF for Fraunhofer Pattern can be calculated using the following formula: DOF = (2 * λ * f * N) / (D * d), where λ is the wavelength of light, f is the focal length of the lens, N is the f-number, D is the diameter of the aperture, and d is the distance between the aperture and the subject.
Yes, DOF can be adjusted by changing the aperture size, using a lens with a longer focal length, or by changing the distance between the subject and the camera. These adjustments will affect the size and clarity of the Fraunhofer Pattern captured in the image.
If the DOF is too shallow, only a small portion of the Fraunhofer Pattern will be in focus, making it difficult to accurately analyze the entire pattern. It is important to have a sufficient DOF to ensure that the entire pattern is captured in focus.