Using a Tak as a Littrow objective/focusing lens VHires R48000!

[NickK]

Now that's something.. take and a hefty priced grating to match!

http://www.astrosurf.com/buil/vhires/test.htm

Using a 6nm Astrodon Ha filter as a rejection filter!

R48000, FWHM 0,14 A @ 6563 A) spectral sampling is 0,0462 A/pixel (bin 3 mode).

What is a neat trick is using the OAG guider prism to inject the beam.. I may have to try that in the next version of my spectroscope

[Merlin66]

5,000 Euro just for the grating is a bit heavy!!

Using an OAG reversed has used by many amateurs - Fulvio Mete etc.

Getting the prism down near the optical axis ( to reduce astigmatism/ gamma angle) is a bit of a PITA. I was impossible with a Meade OAG without significant DIY.

I think one of those new designs from Baader which have a sliding mirror (which can actual function as a flip mirror) would be a help.

[robin_astro]

And remarkably not just for bright objects either

http://www.spectro-aras.com/forum/viewtopic.php?f=6&t=784

With most of the light from planetary nebulae concentrated in narrow lines it is possible to measure them at very high resolution and study the way the gas is moving 

Robin

[robin_astro]

And remarkably not just for bright objects either

http://www.spectro-aras.com/forum/viewtopic.php?f=6&t=784

With most of the light from planetary nebulae concentrated in narrow lines it is possible to measure them at very high resolution and study the way the gas is moving 

Robin

Here is a link direct to the VHIRES post

http://www.spectro-aras.com/forum/viewtopic.php?f=6&t=784#p3578