For maximum scientific yield (including the consideration of creating a useful archival database) in the first editions of this Handbook the following filter sequence (in order of priority) was recommended: B, UVW2, U, UVW1.
After more than two years in orbit it is considered more important to take advantage of the unique capabilities of OM in the ultraviolet domain, and therefore the recommendation is to use:
Although the UVW2 goes further in the UV, its use is not encouraged because of its low in-flight performance.
A different set of filters for observations in the OM default configurations may be chosen by the user, based on scientific considerations. However, the sequence in which the filters are used must follow their order in the filters wheel (see § 3.5.5). The three filters listed above have to be set in the sequence U, UVW1 and UVM2.