sample 55
orange peel

i have confirmed by experiment what has been known for a long 
time: you cannot make orange peel flat. So the sample is not 
rectangular but it is reasonably flat!

aperture: 1 tick past 5.6
this was the setting that still gave a very faint image at dark 
positions, but i couldn't open it further because this sample 
is very specular
zoom:as before
parameters: p=18 l=166 z=330

you can see the glue at the edges

lowest strip is not useful in calibration, not covered by 
orange peel