Tonight I completed the first "rough" star test of the beam-splitter.
Scope out of collimation -due to tube shortening,
Guiding atrocious due to rushed balance,
300D image out of focus due to rush and not parfocalising both imagers
And finally no field flatener on the 300D
Having said that,
The 300D was set for straight through 70% transmission and the ST-7e as a guider in the right angle position 30%. The guide chip was used for guiding.
First image is the guide field. 2 sec exposures. (Moving up to 5pix between exp's).
Second is the 300D with white box demonstrating the guide field 572 sec unmodded.
I think this demonstrates that this system is bright enough to capture spectra on long guided exposures, with the star held on an optical fibre or slit.
Looks like a goer Ken.