OPL Spectroscope

[mikerr]

Hartung stated that he used a "direct vision prism" at the ocular of his telescope to detect if an object was a Star or a Nebula.

I am wondering if one of these Transmission Grating Spectrometers would afford the same/similar crude information when held to the eyepiece?

http://www.oplspectra.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=7&category_id=5&manufacturer_id=0&option=com_virtuemart&Itemid=32

http://www.patonhawksley.co.uk/spectroscope.html

Any thoughts would be welcome.

Michael.

[Merlin66]

The OPL is not really a suitable candidate...
Any of the others you see which say they are "prism" direct vision spectroscope can be easily dismantled to extract the Amici prism assembly. If this is then placeded behind an eyepiece you'll see the spectra from the brighter stars and be able to replicate Hartung's work.
( I started out just using a small 60 degree prism mounted in a film canister to see the stellar spectra - it works well to identify planetary nebula!)

[mikerr]

Thanks for the reply Merlin.

I did find an Amici Prism unit in Germany a while back but the Australian agent quoted me about $600.00. Too rich for me.

I had hoped that a Transmission Grating might be the modern and cheaper equivalent to the direct vision prism.

Today I have ordered a copy of "Astronomical Spectroscopy for Amateurs" to try and learn the differences.

Michael.

[Merlin66]

The Star Analyser filter sized grating from Paton-Hawksley is a good starting point.
I ususally buy my Amici prism D-V spectroscopes from ebay; if you check the specifications carefully, you can normally pick one up for less than 30gbp.

[mikerr]

Thanks Merlin. I will keep an eye on ebay.

Michael.