Online Filter Bandpass Shift Calculator

Whenever narrowband filters are used for astrophotography it may be necessary to use so called highspeed filters, in case the telescope has a fast focal ratio. The main reasons are explained here Narrowband and fast telescopes.

This calculator may be used to estimate the total transmission for a particular combination of filter and telescope and also shows the transmittion in respect to wavelength and radius.

This implementation is based on the mathematical preparation from Cuiv, the Lazy Geek and the online-implementation from Orphi, which I granted to use as a starting point.