Daystar Filters is very proud of our 40+ year history providing research grade equipment to the world's top research institutions. Our process can produce the highest grade quality equipment in the world, with unprecedented uniformity and finesse distinction.
Side-by-Side comparison:
Daystar uses specially produced test equipment which has been independently verified and tuned for precision and accuracy daily (sometimes hourly). Only 3 known sources worldwide posess equipment capable of quantitative analysis of sub angstrom spectroscopy outside of the Daystar Filters laboratory. Analysis from any of these sources is respected and always welcome. Owners are welcome to contact Daystar at any time with service concerns. Should filters sent for service meet or exceed stated specifications without flaw, filters will be returned to the owner in same or better condition.
As each Quark produced may vary from 0.25 - 0.5 FWHM; and each QUARK produced will vary from SE to PE grade, direct side-by-side comparison of one unit vs a different unit does not constitute a standard by which any unit may be qualified or disqualified.
Filters shall not be "upgraded" or exchanged because an SE grade filter is not providing PE grade uniformity or a wider etalon exchanged for a narrower etalon unless that etalon is outside of the stated specification for the product purchased.
All certifications of FWHM and CWL uniformity are performed spectroscopically and mathematically on highly specialized and externally certified spectroscopic equipment.
Users should expect a degree of variation from one QUARK to the next.
This is inherent due to both the lower price structure of the QUARK product line and due to the extremely high precision for isolation of the Hydrogen line which requires tolerances measured in >1/100,000 wave. These variations are caused at the molecular level as the chemicals which make up the mica crystal vary in abundance when the crystal is formed in the earth. They are beyond human control. The only control we have is to qualify or disqualify. Quark filters' specification categories allow for a larger number of samples to be qualified and therefore allow for the lower costing structure.
Daystar Bandpass:
Each Quark is warranted to have a FWHM bandpass (when introduced into a focal plane beam of ~F7-F/9) of 0.25 - 0.5.
Combo Quark filters are warranted to have a FWHM bandpass (when introduced into a focal plane beam of >F/25) of 0.25 - 0.5.
A degree of variation from unit to unit will naturally occur, as different FWHM filters are produced and binned into either Chromosphere or prominence specification categories.
A Quark will never be warranted to perform precisely to the standard of a different Quark or Quantum filter, due to the range of acceptable FWHM bandpass within the stated specification standard. More precise certification and smaller FWHM category ranges greatly increase the production and qualification costs of Quark filters due to degree of optical precision and assoicated cost required.
Clients who wish to achieve exacting FWHM performance should consider the Daystar Quantum filter line. Quantum filters have a higher cost structure partly due to the testing required to certify a specific FWHM.
Daystar Uniformity:
Each Quark is warranted to have a spectral CWL uniformity as stated below.
That uniformity may be of Standard grade or on occasion, the PE grade.
All Quark filters are NOT warranted to be PE grade uniformity.
40+ years' standing Daystar Uniformity Standards:
Our Quantum products are offered in SE grade and PE grade uniformity. All Quark filters are warranted to meet or exceed the SE grade uniformity standard.
Due to scarcity and certification requirements, PE grade uniformity is reserved for our top-end Quantum PE product line.
The uniformity grade of a filter is based on the uniformity in abundances of chemical composition (and subsequent index of refraction) within the natural mica crystal. Prices for the PE grade filters reflect the rarity of the required uniformity in homogeniety.
- STANDARD SE GRADE filters are specified as: Spectral uniformity: The mean peak wavelength of all 12 mm. dia. areas shall be within 0.5 Angstrom of the full aperture wavelength measurement.
- PROFESSIONAL PE GRADE filters are fabricated and qualified to very high uniformity tolerances to the specification of Spectral uniformity: The mean peak wavelength of all 12 mm. dia. areas shall be within 0.05 Angstrom of the full aperture wavelength measurement. (In fractions of a wavelength of light, this accuracy is equal to 1/131,260 wave).
- QUARK Filters share the Standard SE grade filter specifications, and are specified as: Spectral uniformity: The mean peak wavelength of all 12 mm. dia. areas shall be within 0.5 Angstrom of the full aperture wavelength measurement
Due to production processes and scarcity considerations, uniformity above specified SE grade cannot be guaranteed in a production QUARK. Therefore, hand selection of "honey" or "extra good" QUARKS is also not possible. All filters are tested prior to shipping both spectroscopically and visually to meet or exceed the SE grade qualification standard.
UNIFORMITY STANDARDS
