|Star Analyser 100
... 1.25" Blazed diffraction grating for spectroscopy
* Professional Astronomers routinely use the power of spectroscopy to reveal the secrets of the universe. Now the STAR ANALYSER can do the same for the amateur imager at an affordable price with this simple telescope attachment.
* Used like a conventional 1.25 inch filter, it is the ideal accessory for today's low cost astronomical imaging cameras, webcams and video cameras.
* For example, with a telescope of just 80mm aperture and a simple unmodified webcam, the hidden characteristics of hundreds of stars down to magnitude +4 can be revealed. With a 200mm aperture and a sensitive long exposure CCD imager, the identification of bright Novae and Supernovae or even a measurement of the expansion of the universe from the redshift of a Quasar are possible.
You can turn this star into this! (Diagram made with Visual Spec software, not included)
* High quality transmission diffraction grating mounted in a standard 1.25 inch filter cell
* Anti- reflection coated glass protects the grating surface
* High efficiency 100 lines/mm blazed design
* Simple to use - Screws into a camera eyepiece adapter like a normal filter
* Spectrum direction marked on the filter cell. A locking ring maintains the orientation
* Optimised for the small CCD sensors found in popular webcams, video and astro cameras.
* Star and spectrum can be recorded in the same image, which aids identification and calibration
* Grating distance can be adjusted if desired using spacer rings (purchased separately)
* Can also be fitted to an eyepiece for visual use
Tips by Teleskop-Service:
The further away from the camera sensor the STAR ANALYSER is placed, the more spread out the spectrum becomes. If you mount it too close, you will lose resolution. Too far away and you will not be able to fit the whole spectrum in the camera frame. In practise the minimum recommended distance in mm is 4x the pixel size in microns (eg for a ToUcam webcam 4x5.6=22.4mm) and the maximum while still fitting the spectrum (diagonally across the chip) up to 700nm is 12x the sensor diagonal size in mm ie
55mm for 1/4 size sensors like the ToUcam, Neximage, ATK1 etc
75mm for 1/3 size sensors like the ATK2, LPI, DSI, SAC8 etc
100mm for 1/2 size sensors like the Minton 12V1 EX etc
The Freeware-Programm Visual Spec can be downloaded here: http://astrosurf.com/vdesnoux/