
The other, more serious problem encountered with SIM occurs when rem-
nants of the illumination grid structure propagate into the final processed image,
where they appear as artifacts. To illustrate, a sample region of size 240180 mm
2
of a pigeon feather is shown in Fig. 17.7. The image on the left was taken by
a conventional microscope set so that the rightmost area is in focus. The other
image is the EDOF compilation from 11 sections separated by steps of
Dz ¼ 25:4 mm. Structures in the EDOF image appear in focus, but object
structures are obscured by linear artifacts. In this case, a vertical grid was used,
resulting in vertical artifacts.
There