The formula to calculate the diffraction limit of a lens is:
\[ DL = 2 \cdot \lambda \cdot 1000 \cdot \sqrt{1 + A^2} \]
Where:
Let's say the wavelength (\( \lambda \)) is 0.5 micrometers and the aperture (\( A \)) is 2. Using the formula:
\[ DL = 2 \cdot 0.5 \cdot 1000 \cdot \sqrt{1 + 2^2} \]
We get:
\[ DL = 1 \cdot 1000 \cdot \sqrt{5} \approx 2236.07 \text{ micrometers} \]
So, the diffraction limit (\( DL \)) is approximately 2236.07 micrometers.
Lens diffraction is a phenomenon that occurs when light waves encounter an obstacle or aperture, such as the blades of a camera lens. As light passes through a small aperture, it spreads out, causing the image to lose sharpness. This effect limits the resolution of the lens and is most noticeable at small apertures (high f-stop numbers). Understanding the diffraction limit helps photographers and optical engineers optimize image quality by balancing aperture size and the resulting depth of field with the sharpness of the image.