Adapters for Star Analyser and Rainbow Optics Spectroscope gratings

Use your Paton Hawksley Star Analyser or Rainbow Optics Star Spectroscope with a DSLR to produce absolutely wonderful spectra. We prefer the Star Analyser grating because it was designed by a knowledgeable spectroscopist.  He created the Star Analyser specifically for the kind of spectroscopy that amateur astronomers do (link). But many amateurs have also gotten good results with the Rainbow Optics Spectroscope grating.

How to get started in spectroscopy

Have a telescope and cooled astronomical CCD camera already?  Then just screw a grating into the camera nose or your filter wheel. You can easily process the resulting spectrum (rainbow) into a scientific graph using our RSpec software.

See this short Sky & Telescope video interview. Our tutorial videos (link) and active forums (link) make it easy for you to get started. Don’t think you have to be a post-doc researcher with a big budget.  This isn’t your father’s spectroscopy anymore. These days, it’s surprisingly easy.

Using a DSLR

Below is a spectrum taken with just a DSLR showing a Wolf-Rayet star.  See the Carbon emission lines?  That’s the photosphere fluorescing from UV light!  The photosphere on a Wolf-Rayet star is dense, high-velocity wind region surrounding the star.  Even with simple equipment, you can easily spot the Carbon peaks because Doppler shift from the winds has widened them. (Wikipedia)

(Image courtesy of Janet Simpson: Canon 350D, EF 85mm f1.8 USM lens, Star Analyser, and an AstroTrac mount. 20 second exposure, F1.8, ISO 400)

You can capture images like this with your DSLR.  The AD-55 adapter attaches a Star Analyser or Rainbow Optics grating to your DSLR lens. (See photo below.) This is called an “objective grating” configuration. It produces spectra that are two or three times better in resolution when compared to mounting your grating between a telescope and camera.

This is an excellent way to get started, if you don’t have a telescope.  Great for use in educational settings.

Above: Our adapter is made of black-anodized, light-weight aluminum. It screws into your DSLR lens cap/filter threads.  Your grating then screws into the adapter. Use it with a Star Analsyer, a Rainbow Optics Star Spectroscope, or any filter grating (including nebula filters, etc.)

For the best spectra, use with an 85 to 150 mm lens.   You don’t even need a driven mount! For brighter objects, simply orient your grating so that the star-drift is perpendicular to the dispersion direction.  For additional information, see Robin Leadbeater’s site (link),  email us (link), or post a question to our forum (link).

Technical details: Our adapter’s male threads are 55 mm and screw into the female filter threads on your DSLR lens.

Adapter Rings

If the filter threads on your camera lens are not 55 mm, you can order a step-down or step-up ring from this site: link.

The “From”-end of the ring should have male threads that match your lens’ filter threads.

The “To”-end of the ring should be 55mm female into which our AD-55 screws.

Feel free to email us if you have questions.

Your Star Analyser 100, Rainbow Optics StarSpectroscope grating, or any 1.25″ filter screws directly into the 1.25″ inner threads of any AD-55.

Cost for the AD-55 is only $38 plus shipping and handling.  Available now!  Click here to order.

T-Ring Adapters

We also offer our AD-T2 adapter that mounts a grating into a 42 mm T-Ring that you already own.  Refer to photo below to see how it works.  Total distance from the camera sensor to the grating when using a our AD-T2 is about 70 mm.  Depending on your hardware geometry additional spacers may improve the spectra: link.  (The AD-T2 is not for use on webcams, whose sensors are too small for this spacing)

Cost for the AD-T2 is only $38 plus shipping and handling.  Available now!  Click here to order.