M28 to M42 Camera T-ring Adapter for 1.25" Star Analyser
M28 to M42 T-ring Camera Adapter for 1.25" Star Analyser for "PRIME FOCUS IMAGING WITH GRATING" Configuration
We offer now our M28-T2 adapter that mounts a Star Analyser 100 or Star Analyser 200 grating into a 42 mm T-Ring that you already own or you can buy one from us (you can buy a wide range of T-rings for possibly all types of camera mountings for our online shope at www.365astronomy.com...)
Images are for demonstration purposes only. Telescope, Star Analyser, dSLR camera, T-ring and T-extension are not included but available separately.
Female T-thread (M42x0.75) on one side (5mm)
Male T-thread (M42x0.75) on the other side (5mm)
Female M28.5mm filter thread (threaded through:7mm)
Overall optical length: 7mm
Refer to the photo below to see how it works. When used with a dSLR, the total distance from the camera sensor to the grating (when using our M28-T2 adapter) is about 57 - 60 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, but it will work well with CCD or CMOS cameras like the ZWO ASI174, ASI1600 or ASI071 series.
You can now use a dSLR to take the spectrum of a star and other celestial objects by using this adapter in combination with the Star Analyser 100 that is available separately.
Click here for Tom Field's Star Analyser Calculator!
With the Star Analyser 100.... ...turn this... ...into this!
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 link)
(Image courtesy of Janet Simpson: Canon 350D, EF 85mm, Star Analyser 100, and an AstroTrac mount. 30 second exposure, F1.8, x 6 stacked, ISO 400)
You can capture images like the above with your DSLR. Bear in mind that the above image was taken with a dSLR in a so called “objective grating” configuration. It produces spectra that are two or three times better in resolution when compared to mounting your grating in prime focus between a telescope and camera, but of course that might not always be ideal, if you are pointing at very faint objects that will be possible to capture only through your telescope, in which case you would need this M28-T2 adapter for "prime focus" configuration.
For further info contact us at 365astronomy or Tom Field here (link).