aperture refractor, a FSQ106ED Takahashi astrograph (106-mm diameter).
I use a EXQ-1.6x Takahashi extender (F/7.8 final beam) and the spectrograph
is equiped with a 19 microns width slit (ideal for this small instrument).
Here the field of supernova SN2014G in NGC 3448 with the FSQ106ED in
imagery mode (F/5 focus) - 4 x 300 sec. exposure QSI-583 CCD camera:
The same object captured by Alpy 600 guiding camera (Atik314L - 60 sec):
(note the narrow slit and the sharp aspect of the star - thanks to the short
focal length of used refractor and high optical quality).
The supernova is at V 14.6 (!), type IIn (no detail on the continuum for the
moment). The spectrum is noisy, but remenber the aperture of the telescope:
Another example on nova Monocerotis 2012 at V = 14.7 taken the same night
and with the same isntrument:
Now a faint object. The spectrum;
More brigthness object, typical Be star with Alpy 600 spectrograph:
V1307 Ori at V = 9.5 :
Christian B