Visualization of image distortions:

image distortion: loss of focus (σ=1)
loss of focus (σ=1)
image distortion: loss of focus (σ=2)
loss of focus (σ=2)
image distortion: loss of focus (σ=3)
loss of focus (σ=3)
image distortion: loss of focus (σ=4)
loss of focus (σ=4)
image distortion: loss of focus (σ=5)
loss of focus (σ=5)
image distortion: loss of focus (σ=6)
loss of focus (σ=6)
image distortion: loss of focus (σ=7)
loss of focus (σ=7)
image distortion: loss of focus (σ=8)
loss of focus (σ=8)
image distortion: loss of focus (σ=9)
loss of focus (σ=9)
image distortion: loss of focus (σ=10)
loss of focus (σ=10)