Astronomy product line
We supply custom and stock filters to the highest imaging quality standards for professional and amateur astronomers and atmospheric scientists throughout the world. Applications include both terrestrial and space-based observational instruments. Whether it's custom filters or prescription sets, we have successfully completed complex projects for a wide variety of university programs, observatories, government agencies, and international consortia.
Bessell Photometric Filter Sets
Our stock Bessell Photometric Sets manufactured to the prescription put forth by M. Bessell, offer high optical quality suitable for demanding imaging requirements. Filters are polished to stringent transmitted wavefront distortion, wedge, and flatness specifications and are then anti-reflective coated. Each filter's spectral response is determined by the combined response of two or three Schott filter glasses polished to prescription thicknesses. The individual glasses are then laminated into a single-piece optical assembly. The result is a set of precision prescription filters at an economical price.
If your application requirements differ in physical dimension or optical performance from our stock items, we can customize individual filters or sets.

Imaging Enhancement Attributes:
- Maximum transmitted wavefront distortion: l/4 (or better) per inch.
- Maximum wedge: 30 arc seconds.
- Minimum flatness: l/4 (or better) per inch.
- Surface quality: E/E as defined by C-48497A.
- Anti-reflective coating: dielectric AR coatings on both surfaces to increase transmission and reduce ghosting.
- Anti-reflective coating durability: to moderate abrasion as defined by Mil-C-48497A (cheesecloth test).
General Specifications
- Spectrophotometric curve(s) provided for each filter or set.
- Instructions are provided for handling and cleaning surface-coated optics.
Custom filters for astronomy
Many astronomy imaging applications require the custom design and manufacture of filters and filter sets. We can provide filters to the following general specifications:
- Wavelength Range: UV to mid IR.
- Bandwidths: 0.15nm to several hundred nanometers.
- Tolerances: Demanding throughput, band shape & band width requirements.
- Sets: All Filters with matching physical & performance attributes.
- Materials: Space-flight compatible

