[bojan]

While waiting for BW CCD sensor for my Logitech 4000 camera (I will also attempt the long exposure mod then), I was playing with SA100 grism, mounted on C11.

I took spectra of Betelgeuse and Sirius on Wednesday evening... it was quick&dirty job, exposure (couple of seconds) was done with moded Canon450D @ ISO100. To avoid saturation, I drifted the scope along RA, thus obtaining wide spectra like there was a slit in the light path...
Of course, this was possible only because both stars are sufficiently bright.. With fainter objects, I will have to use higher ISO settings and longer exposures with accurate tracking.

It was relatively easy to align the grism in my mechanical solution - grism is rotatable with respect to camera (~+/- 10degrees), and of cource the whole thing can be rotated so the flrame could be aligned perpendicluar/paralel to celestial coordinate grid.


EDIT:
In the current setup, grism distance from sensor is ~100mm (limitated by prism holder diameter and inner diameter of the C11 baffle tube).

There is a bit of overlapping of second order spectrum at IR side (right side, not easily visible on attached images), I will sort it out with 680nm IR filter (I have one left over from Canon 400mm FP lens setup, now I will use it here).