def __init__(self, out_dir, n, spacing_steps=1, dry=False):
#dry = True
self.dry = dry
self.out_dir = out_dir
if n % 2 != 0:
raise Exception('Center stacking requires even n')
self.n = n
self.n2 = n / 2
# Specify in steps to be very exact instead of units
self.spacing_steps = spacing_steps
if self.dry:
self.mc = DummyController()
self.imager = DummyImager()
else:
self.mc = MC()
self.mc.on()
self.imager = PILImager()
