BF blocking filter: The deflection optics with the eyepiece receiver also accommodate the blocking filter. This filter reduces the brightness of the solar image and is therefore a very important part of the solar telescope, and which must under no circumstances be removed! For purely visual observing, a small blocking filter is sufficient, but for photography a larger one should be selected.
The B1800 blocking filter is very well suited to visual solar observation but can also be utilised for solar photography using cameras with a small sensor chip or which use the APS-C format. For cameras with large sensors, a telescope with a larger blocking filter should be used so that the sensor will be illuminated. For solar photography, we generally recommend so-called planetary cameras which work smoothly with this blocking filter.
Because the LS50 has an estimated bandpass of <0.70 Angstroms it is capable of providing high contrast views of both surface and edge detail. Adding an additional etalon system will reduce the bandpass to ~<0.50 (dependant upon scope) allowing for higher resolution viewing and/or imaging.