Quote Originally Posted by holmburgers View Post
I thought the idea was that you projected them obliquely onto a surface and the spectral beams naturally decrease in intensity as they travel, no step wedge needed.

Or a step wedge works too.
Nope. You need a step wedge. You also should know the frequency in nanometers if you are to read a B&W spectrogram. With color, it is a bit easier.