Getting started

There are lots of different equipment configurations with which you can do RSpec spectroscopy. Below are some suggestions. We haven’t tried them all, but these are the kinds of approaches we’ve seen in use.

Are you new to spectroscopy? An RSpec user, Iain Petrie, wrote a great, two-part introduction to the field. Read his posts from the bottom of each page to the top for chronological order. Set one: link. Set two: link.

Have questions? Fill in our contact form (link) to have our Help Desk experts email you. We specialize in getting newcomers up and going.

Also, see this link about the free Zoom webinars that we offer. These webinars are great for a club meeting. They are a complete introduction to the fundamentals of spectroscopy, the equipment needed, and the kinds of scientific results you can expect.

Here’s what you need to get started in the field of telescope spectroscopy:

1. RSpec software: you can download a free, fully-enabled 30-day trial version of RSpec from this link. If your trial period runs out, just send us an email. We’re happy to provide you with a one-time extension. You can also purchase a copy of the software in our store: link.

Even without clear skies or a diffraction grating, you can get started today with the trial version and a sample spectrum you can download by right-clicking and saving the file at this link. This is a .png file, but RSpec handles FITS files too!

Also, see link for additional sample files and a YouTube video of a workshop Tom gave on processing.

2. Diffraction Grating: We recommend the Star Analyser 100. It comes mounted in a standard 1.25” filter cell which screws into your CCD imaging camera, your telescope’s filter wheel, or the nosepiece of your video camera, or your DSLR. With 100 lines/mm, the Star Analyser 100 was specially designed amateur spectroscopy. Details: link.

Note that capturing star spectra requires that you already be somewhat proficient at capturing images of astronomical objects.  You will need to be able to find those objects, and you will need to be able to capture images of them that are properly exposed, well-focused, and not smeared from movement.  We’re happy to advise you on how to get started.

Cameras

RSpec can process real-time video, FIT, JPG, BMP, TIF, or RAW images from any source including DSLRs and your current astronomical camera.

Video Cameras

For camera, your camera needs to be DirectX capable. Most of the popular astronomical video cameras (like ZWO, etc.) come with DirectX drivers.  For other cameras, ask your vendor about DirectX capability.

Or, rather than DirectX, if your cameras work well with SharpCap, RSpec can seamlessly read live images and video as SharpCap aquires them.

For inexpensive video, we recommend cameras from ZWO: the color ZWO ASI120MC-S or  mono ZWO ASI120MM-S.  For a larger sensor, see the ASI178. (ZWO link) Mono cameras are more sensitive. Color cameras can introduce artifacts but are usable and better for outreach and education.

Other cameras: For a bit more sensitivity and general performance, see the ZWO ASI190MC  and ASI190MM. RSpec can show live video spectra from most astronomical image cameras, including ZWO, and the QHY5-II series and QHY5-III series, and others.

Have a DSLR?  For video with a Canon camera, see Canon’s ESO Webcam utility: link. For other cameras, see  www.sparkosoft.com to use RSpec with a live DirectX feed from your DSLR.

Confirm your setup in our calculator: link. In most cases, you just screw your diffraction grating into the nose of these cameras, and you’re ready to go. If you use SharpCap or other camera control software, you can continue to use the same software. RSpec can read images from those programs in real-time.

Sample camera

If you already have an astronomical FITS camera, RSpec will read and process FITS images from it. You can continue to use your standard camera control software and RSpec will load images as they are saved to your drive.

With many cameras, you simply thread our 1.25″ Star Analyser 100 grating into the nosepiece threads of the camera. If you’re using a filter wheel, you can use our Star Analyser 200 grating. For more information on gratings, see this link.

Mono or Color

If you’re doing public outreach or teaching with RSpec, we recommend a color video camera. A color spectrum image is much more interesting and intuitive rainbow than just black and white. Mono cameras can produce more detailed spectra and are more sensitive, but a grey smudge.

If you already have an astronomical video camera that you use with your telescope, and if it can accommodate a 1.25″ filter cell for the diffraction grating, then you probably have all you need. To get the best spectra, the grating should be located at the optimal distance from the camera sensor – see our calculator (link) and read about spacers at this link.

Using your DSLR as a live video camera: The Canon 450d and other DSLRs can generate live video. With many cameras, the addition of an inexpensive software or hardware DSLR-to-webcam converter (to DirectX/DirectShow) as described above lets you feed real-time video from your camera into RSpec. This configuration can get remarkably good results and is extremely simple to set up.

Static image CCD and CMOS cameras

Although real-time spectroscopy using live video is easier and considerably more exciting, a standard astronomical FITS camera will yield better overall results and allow you to capture dimmer objects.

Do you have an astronomical FITS camera already? RSpec will read and process FITS images from any camera. Looking to upgrade your camera or buy a new one?

RSpec handles FITS, JPG, BMP, PNG, and RAW images straight out of the box.  

Or, rather than DirectX, many cameras work well with SharpCap. RSpec works seamlessly with SharpCap, both live video and live images.

With many cameras, you simply thread our 1.25″ Star Analyser 100 grating into the nose piece threads of the camera. If you’re using a filter wheel, you can use our Star Analyser 200 grating. For more information on gratings, see this link.

In addition to astronomical FITS camera images, RSpec can process RAW, JPG, BMP, and PNG images from, for example, a DSLR. You can configure RSpec to automatically load each new image file as your camera saves them to a specific folder on your hard disk. We offer special adapters ($42) to mount a grating on your DSLR: link.

Computer

RSpec runs on almost any Windows computer (1+ gigs of RAM, Windows 10 or 11).  For larger format cameras or live video, you’ll need a computer with a bit more processing power than the low-end, low-power mobile Celeron-type chips.

 Ask us questions! Use our live chat form to talk to us directly: link. Or, you can use our contact form (link). Don’t be shy  — we love answering questions!

Also, our online forum is a great source of information from a helpful community of experienced users: link.