Optical prism for exploring spectral lines

[Mikaellm1234]

Hello!

I am looking to explore and compare spectral lines.

I am seeking a good (and not too expensive prism) that can refract light so that I can analyse the spectrum

I have a few questions:

- if you wish to photograph the spectrum with spectral lines so that you can compare and zoom using software, do you need the prism to somehow be attached to a telescope or is it possible to simply have the spectrum on a background that you can photograph it

- what kind of prism do you recommend?

A link to good prisms as well as maybe a guide or knowledge on how to view and photograph it would be highly appreciated

Have a lovely day!

Clear skies,

Mikael

[riklaunim]

Check out Star Analyzer - it's a diffraction grating in a 1,25" filter cell. You can also make something cheaper and get plain diffraction grating, mount it before DSLR lens and point that on bright stars.

Sirius with Star Analyzer and a mono planetary camera gives a spectrum like:

With vspec analysis you can get:

But that can be even better when you normalize for given sensor spectral response

With diffraction grating and no slit only point light sources can be analyzed that way, but if you point it on a nebula on a small resolution then you will get few copy-images of it as it will glow only in those narrowband bands we all know from a different point of view

For example Saturn Nebula:

[Merlin66]

Nowadays it's easier with a grating than trying to find large, quality prisms.

The basic is a transmission grating used either in front of a camera lens (<200mm fl) or mounted in the telescope optical path in front of the camera.

There are various software options to process the spectral image into calibrated profiles.

Robin L. has some good introductory material on his website

http://www.threehillsobservatory.co.uk/astro/spectroscopy_equipment.htm

and also David H.

http://www.stargazing.net/david/spectroscopy/index.html

Then there's the book:

http://link.springer.com/book/10.1007%2F978-1-4614-1397-4

[Dave In Vermont]

I'll second the StarAnalyzer:

http://www.rspec-astro.com/star-analyser/

Or this one is about the same - from the USA:

http://www.starspectroscope.com/

Clear & Colourful Skies,

Dave

[ronin]

Prisms are not the way to go, they are nice in some ways but fitting one to a scope is difficult, it is not a straight through optical path.

Didn't you ask this about a week ago ?

http://www.astrosurf.com/buil/us/stage/calcul/design_us.htm

http://www.vikdhillon.staff.shef.ac.uk/teaching/phy217/instruments/phy217_inst_basicspect.html

Also one of these may be useful

http://www.stargazing.net/david/spectroscopy/links.html

[robin_astro]

The basic is a transmission grating used either in front of a camera lens (<200mm fl) or mounted in the telescope optical path in front of the camera.

like this   :-)

http://www.threehillsobservatory.co.uk/astro/spectroscopy_11.htm

Cheers

Robin

[Mikaellm1234]

Thanks for all the feedback!

Regarding the Star Analyser, is it possible to get a 2" filter?

My setup is a DSLR with a 2" coma corrector with T-ring system. Therefor, how do I attach a 1.25" filter?

[robin_astro]

Thanks for all the feedback!

Regarding the Star Analyser, is it possible to get a 2" filter?

My setup is a DSLR with a 2" coma corrector with T-ring system. Therefor, how do I attach a 1.25" filter?

There is no 2" size Star Analyser but there are various adapters around which might suit your system eg

http://www.scopestuff.com/ss_tfa1.htm

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p4985_TS-Adapter-for-1-25-inch-filters-to-2-inch-filterthreat.html

http://www.teleskop-express.de/shop/product_info.php/info/p556_Baader-continuous-male-T2-thread-with-1-25--Filterthread.html

http://agenaastro.com/blue-fireball-m48-male-m28-5-female-adapter-m-01.html

You can also use the optional mounting kit

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

to mount it into a 2 inch filter cell

http://www.threehillsobservatory.co.uk/astro/spectroscopy_16.htm#SA200_mounting_kit

which works with both the 100 and 200 lines/mm Star Analysers

Note that vignetting is not a problem provided you place the zero order star image in the unvignetted area

The calculator here  can help you work out whether to go for the SA100 or SA200  and the best distance to mount the grating  

http://www.patonhawksley.co.uk/calculator/

and the manuals are here

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

Cheers

Robin