Wanting to capture spectra of Jupiter and Saturn, I decided to try the "objective grating" configuration figuring that it would minimize the size of the zero angle image as well as increase

Lol. Sent from my Verizon, Samsung Galaxy smartphone

And of course I misspelled "Aberrations" in the graphic... sigh

And Tim's observations and advice are spot on. Thanks Tim! Cheers Robin -- www.threehillsobservatory.co.uk Celestron C11, EQ6, ATIK 314, 428 Star Analyser 100,200, ALPY 600,200 LHIRES III

OOPS pressed send before I finished !

On Fri, Aug 28, 2020 at 04:59 AM, Ken Harrison wrote: The grism (gratings-prism) was proposed by Edwin Carpenter back in 1963.A few words here in my official capacity as the developer of the Star

On Fri, Aug 28, 2020 at 03:00 AM, Ken Harrison wrote: In good seeing the zero star image will be very small.Hi Ken Not with an 8 inch SCT at prime focus that Celso is talking about. (The default

Hi There is some interesting viewpoints here. Let me add some of my observations to it. I use Rspec to help me with the focus. It allows me to measure just how deep the aborption lines are. The

Some exposures with the 200 l/mm (25mm aperture) mounted on the 85mm Canon Prime and Modded Canon 1000D. The 30sec started to show excessive background and the 60 sec even worse. Good result was the

The grism (gratings-prism) was proposed by Edwin Carpenter back in 1963. The Carpenter prism has the front face square to the incoming light beam (no deviation or dispersion), at the rear prism face

There seems to be a significant uptick lately of interest in the Star Analyzer Prism. This prism is an accessory designed specifically for use with the SA100 grating. Because I had some conceptions of

Faintest star spectra - I'm sure the users of the gratings and 8" SCT's will be able to reply, based on their results. Resolution - I still use the TransSpec spreadsheet for guidance. In good seeing

Greetings all, Would it be possible to use Star Analyser 100 and RSpec to characterize spectral response curves for each independent color channel of a DSLR, and also for the combined white-light

I thought this might interest a lot of you. It's an animation that shows the effect of increasing resolution. The values far exceed what our equipment will do. And it's unlikely that any of us are

Well, is very cloudy right now but will give it a try. I have a DSLR with a 250mm lens and a AT72ED, both with a tracking mount. Am getting Slooh Telescope image of area tonight to see what it looks

Hi The 6” thin prism could be a lot fun if you try it. Yes, it would give you non-linear results, but if start with a bright star (Vega) you would be able to calibrate it. Sent from Mail

This is the image on Christian Buil's page I am referring to (He is the world's most famous and most experienced amateur spectroscopist. I know him personally and I trust his results)

On Thu, Aug 27, 2020 at 02:22 AM, cpamontalvo wrote: The other question to solve is the resolution of the spectra. I have read that for the Star Analyzer 100 de resolution limit is 50 A.Hi Celso, It

On Thu, Aug 27, 2020 at 02:56 AM, Ken Harrison wrote: A rule of thumb: for the converging beam arrangement and good seeing etc. the resolution is around 2 to 3 times the dispersion i.e. a dispersion

On Thu, Aug 27, 2020 at 02:56 AM, Ken Harrison wrote: think getting 10 mag star spectra with the 8" SCT will be problematic.I don't understand why you think that Ken. My estimates are based on 18