ZWO LRGB FILTERS 31mm

This new set of 4 LRGB 31mm filters is not mounted in a cell and it is designed to fit on the ZWO filter wheels. This design allows to use telescopes and lenses with a focal ratio up to f/2 without causing vignetting. 

The width of its bandpass is balanced with the spectral response of the ZWO cameras, in particular the ASI1600MM Pro. This expedient allows to balance the exposure of each channel with the ratio 1:1:1. That means the exposure time in red is equal to the exposure time in green and in blue.

The L filter is an IR-UV cut filter for the luminance. 

The filters are parfocal so there is no need to refocus when the filter changes. The surfaces of the filters are optically polished and fully multi-coated. 

Each filter cuts off the ultraviolet and infrared violet so there is no need to use the L filter in combination with the colour filters.