DH 4.0 v4 Spectrometer Build Illustrations, Modifications and Specifications
This is what my spectrometer looks like at the present moment...
This is the view with the forward face cover on. ( it would be covered when doing fluorescence spectra, then you would remove the plug on the side for your 90 degree angle.) do the opposite for absorption spectra, remove the front cover and place the plug back in the side.
The cuvette holder is designed to accommodate both forward facing geometry and perpendicular geometry ( 90 degree) as well.