Quote:
Originally Posted by robz
As per Rob_K's post(link on post number 20), the image of the last solar spectrum of three with the lines labelled, is EXACTLY what I see visually with a CD spectrum  .............so what gives here guys.......there is no ''hashy'', rough as guts ''dirty'' looking spectra........just a smooth one with many, many lines???? 
This is all with a reflective(not transmissive) grating at an an odd angle with a very dodgy slit, and viewing hole.......no lenses or cameras, needles |
Yep Rob, sorry, I wasn't casting nasturtiums on or ignoring your method - I intend to go there when the Sun comes back!
The reason for going the needle first was that it acts like a slit and is highly reflective, like a mirror. Mind you, the needle I chose was ROUGH!!! It would work a lot better with a smoother needle. I'd still be a little worried that a surface like the side of a white shed might or could introduce absorption lines of its own, depending on the surface composition. And that might vary from white-shed to white-shed. But those could easily be weeded out. I was super-impressed with what you put up!
Cheers -