What I want to do or know
I am constructing (reconstructing) the mini-spectrometer. I would like to know if the slit on the front end should lie in the same direction of the diffraction grating, i.e. if the "grating is vertical, making a horizontal spectral rainbow" - as mentioned under #2 of the instruction sheet; then the slit should also be vertical? (but in the diagrams of #3, the slit is drawn horizontal.
Thank you for any advice. wlkwong