Line in stud recess 1 80 deg. (almost vertical) - mark in stud recess 7

Line in stud recess 1 55 deg. - mark in stud recess 7.

a

Line in stud recess 1 30 deg. - no mark in stud recess 7.

b

Line in stud recess 1 20 deg. - no mark in stud recess 7.

c

Line in stud recess 1 10 deg. - mark in stud recess 7.

d

Line in stud recess 1 0 deg. (nearly horizontal) - no mark in stud recess 7.

e

Line in stud recess 1 -10 deg. - mark in stud recess 7.

f

Line in stud recess 1 -20 deg. - mark in stud recess 7.

g

Line in stud recess 1 -30 deg. - mark in stud recess 7.

h