sample 38 the ribbed white paper
this is the first anisotropic sample. 
Images are taken as usual and an extra picture is taken with 
the sample 90 degrees rotated around its own axis. this picture 
has the same name except for the third letter which is 'b' 
instead of '-'.

set aperture between 11 and 16
zoom at 1 tick above 60

i homed the robot and checked the robot calibration parameters. 
There can be a deviation between 1 and 2 degrees. If you 
calibrate and replace the sample this deviation can be there 
again. So i guess this is due to the samples (not completely 
falt) the variations when you put a sample in the gripper, and 
the repatability of the robot positioning (errors in this 
order).

parameters z=360 p=19 l=164

moved the lamp a tiny bit. i have the impression that the beam 
is not as homogeneous anymore as it once was. i'll do a full 
standard calibration today.

noticed that the sample is not completely vertical/horizontal 
at 0/90 positions. This is maybe partly due to an error in the 
calibration but also because the sample is not glued exactly 
straight on the holder. Of course for this sample the effect is 
huge since it is so regular. I just continue, and pay attention to 
this for the other anisotropic samples.