The beam splitter diverts a portion of the light to secondary attachments such as the second observer tube, video or digital cameras. Haag-Streit offers beam splitters in different versions.
The one for co-observation under equal conditions diverts only 50% of the light.
Video or digital cameras can be connected to the beam splitter with a range of C-mount adaptors, which offer different focal lengths for variable sensor sizes.
The 50/50 beam splitter is only available for the Haag-Streit BQ 900 slit lamp.