i would not mind. I have a huge 6"x3" grating from a solar scope I was given That I use to get a single rainbow from but that would be really nice/
Ive got a 4 x 4 Jarrel-Ash interferometer grating that's no longer scientifically usable but serves double duty as a rainbow maker in my studio window. 1180 grooves per mm and blazed at 5000A.
Will there be three phase!!!!
The grating Ed made is about 8.5x11", and is a transmission cross grating. I stuck it in the corner of the window. He makes much more complex gratings as well.
What does he sell them for?
Don't know. He's a lurker here, I'd recommend sending him a PM. He's also here: http://edweslystudio.com/WelcomeFrameset.html