pinhole size = aperture!
pinhole “blur” simulated
Light diffracts
-wave nature of light
-smaller aperture means more diffraction
Larger pinhole = Geometric Blur
For d(pinhole diameter), f(distance from pinhole to sensor), and π(wavelength of light)
d = 2√1/2f*π
Geometrical optics
– parallel rays converge to a point located at focal length, f from lens
– Rays going through center of lens do not deviate (function like a pinhole)
Ray tracing with lense
1/0 + 1/i = 1/f
Traditionally, 15-135mm focal length are used for portraits