[Shiraz (Ray)]

Originally Posted by RickS

Hi Ray,

Late to the party (I've been away for a few weeks) but your formula is effectively the same as one I've been using in a spreadsheet for comparing scope/camera combinations

I don't see that Drizzle is relevant to the calculation as it is something that happens after data capture and it doesn't violate the TANSTAAFL principle. For those interested in the theory: http://www.stsci.edu/hst/HST_overvie...34.html#385457

Cheers,
Rick.

thanks Rick - exactly what was needed.