Posted 16 March 2013 - 06:04 AM
Posted 17 March 2013 - 05:01 AM
Posted 19 March 2013 - 06:33 AM
very adaptable and easy to make, and I had most of the bits in my box.
The lenses are just 50mm bino objectives, the folding mirror came from an old etx, the grating was donated.
Posted 19 March 2013 - 11:17 AM
Posted 20 March 2013 - 08:50 AM
Is it possible to get measurements I have managed to get nearly all bits apart from lenses.
Posted 20 March 2013 - 07:57 PM
This might be of interest, click on the machanical button left side for drawings.
If you get all the parts, you can mach up the spectrograph on the table and take measurements from there. I use a cad program a lot too, just going from the lens FLs and camera spacings etc.
John, I like that, nice...
Posted 21 March 2013 - 03:34 AM
Simspec will help tweak your design.
I drew it out full size before assembly.
A good grating is the heart of the instrument, worth investing in. I have seen a 25mm square 300 l/mm for ~£70, I'll dig out the link.
just a thought, have you tried using a bit of CD as a grating, just to get going with? Iris has a 'smile' filter to straighten out curved lines :-)
Posted 22 March 2013 - 03:44 AM
An easy start in spectroscopy is the transmission grating, Rainbow optics do a screw in grating filter. I just wedged a piece of grating into a T mount to get started.
Here's a write up of my experiments;
https://dl.dropbox.c... for Amateur...
Maurice Gavin (Nytecam) has successfully carried out a lot of amateur work.
Try searching his older posts.
Ken Harrison (Merlin66) has published a book on entry level spectroscopy;
Astronomical Spectroscopy for Amateurs
Series: Patrick Moore's Practical Astronomy Series
Harrison, Ken M.
1st Edition., 2011, XI, 181 p. 197 illus., 39 in color. With online files/update., Softcover
Posted 23 March 2013 - 04:45 AM
Hi Peter - although the CD/DVD makes a solar spectroscope [just stare into the surface with sunlight grazing across it to see the Frouhofer lines!] it's too crude for a 'real' spectroscope as John C describes so a grating must be acquired - check out your local college or school lab for discarded parts :o
Thanks Greg, there is a lot of info there, what I was thinking is it possible to use a CD and say a 200mm camera lens. peter
Posted 24 March 2013 - 03:26 PM