8.6 CMOS Files

Since CMOS are created from CMAPs, the caveats above apply as well as the following:

• In some mosaic images, especially with low backgrounds, a pattern resembling a wire mesh can be seen. This is caused by the bad illumination of the edge column and which is then repeated throughout the mosaic.
• When constructing mosaics from CMAP images, no optical distorsion is taken into account. This may lead to blurred point sources.