Baader 2'' ClickLock Diagonal Mirror 300PX there is no real practical

there is no real practical reason for the use of special patterns for different telescope types and focal lengths

There is also a ZWO Forum here for ZWO camera users: ZWO USER GROUP

as standard

whilst trying to judge the size of a tiny point source of light

Baader 2'' ClickLock Diagonal Mirror 300PX there is no real practicalClickLock Mirror Diagonal (2inch) 2" ClickLock Diagonal Mirror Oversized 2 "dielectric lamda 10 levels with 112mm optical length Mirror repels UV and IR radiation, provides high security at the solar observation in white light and with Ha sun filters Scratch resistant, hard coated mirror surface for safe cleaning, scratch resistant even in extreme conditions Baader 2" ClickLock clamp for ultrafast clamping action Removable 2" Safety Kerf nosepiece