Advanced Telescope Supplies

Australia's Premier CCD and Astro-Imaging Experts

Custom Scientific Filters


Custom Scientific manufacture a range of Astronomy Filters, including Bessell formula UBVRI photometry sets, and narrow band Hydrogen Alpha filters.








Of particular interest to CCD users are the Custom Scientific Hydrogen Alpha filters.

 These precision interference filters are centred on the 652 nm hydrogen alpha wavelength, being where many emission nebulae have their strongest intensities.



Using a H-Alpha filter in conjunction with a CCD camera delivers superb high contrast images of these objects, as can bee seen in the images below.


Custom Scientific 3nm Bandpass H-alpha filter 
CCD Image though 130mm refractor  (2mins exposure)
Custom Scientific 10nm Bandpass H-alpha filter
 CCD Image through 130mm refractor (2mins exposure)

ATS can supply these specialised filters on a timely basis 4.5nm H-Alpha $A 430 inc GST 10nm H-Alpha $A 340 inc GST

1.25" Scientific grade 3nm H-Alpha filters $A1500

(price subject to change without notice)


Custom Scientific Bessell formula photometry filters prices are around $A2000 for a complete set including a SBIG carousel. Exact price available on request due $A to $US exchange variations.








Custom Scientific Filters Typical Specification
CWL Tolerance +/- 10% and +/- 15% of FWHM
FWHM Tolerance +/- 10% and +/- 15%
Blocking 300-1200nm .0001 average transmission, no leaks beyond ).01%
Flatness 1/4 wave per inch
Parallelism 2 arc minutes
Pinholes None visible per MIL-C-13830 viewing chamber
Anti-Reflection Coatings less than 1% per surface
Scratch Dig 60-40



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