The black square is the 4r4 mm2 aperture through which the spectrum was acquired.
Each of the 1024 photodiode array elements had a sensitive detector aperture of 25 pm x 26 pm.
Measurement parameters were the total number and the vertical distribution of empty apertures.
Implements varied in shape and size with alternative arrangements for the clay cylinder, the aperture and the mechanisms for forming and cutting the tiles.
Exposure time and aperture were then set automatically by the camera.
In one experiment, swimming through one aperture produced a mirror image and swimming through the other produced food.
The dimensions of the object manipulated are larger than the width of the aperture; this fact does not allow an insertion purely horizontal.
The aperture and focal length on the camera are set according to need.
