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Optical Testing

Our Approach

AG Optical Systems LLC employs a rigorous interferometry testing process to ensure that our customers receive high quality optics.  We do not compromise when it comes to testing mirror blanks for detrimental internal stress, the quality of the lenses we use in our corrector, and the coatings we use on our optical components.

We appreciate that an AG Optical Systems telescope represents a significant investment and we are commited to ensuring that we exceed your demanding performance expectations.

Optical Grade Fused Quartz Optics

AG Optical Systems uses only optical grade fused quartz optics in our telescpes.  Fused quartz is an amorphous, non-crystalline, extremely thermally stable material (1/6th the thermal expansion compared to Pyrex and borosilicate glass) that provides outstanding optical figure and focus stability as temperatures change over the course of an evening.


All AG Optical Systems telescopes are tested using a rigorous, double-pass interferometry process.  Interferometry is the acid test of optical testing and is used extensively through the aerospace, scientific, and commerical optics industries to verify the quality of optical systems.

Each AG Optical Systems telescope is provided with an interferometry test report detailing the Strehl ratio and RMS wavefront error of the telescope optical system.  This is a system level report that is obtained from hundreds of data points measured at the wavefront of the entire optical system.  

Below is an actual interferometry test report from an AG Optical Systems 17" Imaging Dall Kirkham.  This telescope has optical grade fused quartz optics figured by Ostahowski Optics to an exceptional level of performance.

It is generally accepted that a telescope with a Strehl ratio of .80 will provide good optical performance. Telescopes with a Strehl of .90 or greater are generally considered to offer excellent performance. 

AG Optical Systems is one of very few telescope manufacturers to provide interferometry test results with every telescope we produce.  We do not think it is an unreasonable expectation for our customers to know (rather than guess at) the optical quality of the AG Optical Systems telescope they are purchasing.

Corrector Lens Element Testing

AG Optical Systems receives interferometry test reports on the corrector elements used in our telescope.  Rather than seek a cheap oversea source for these critical telescope elements, AG Optical Systems purchases our lenses from an established US-based optics manufacturer with extensive experience producing optics for aerospace, military, satellite, and commercial optical systems.

Below is an actual interferometry test report for a lens used in a corrector for an AG Optical Systems Imaging Dall Kirkham astrograph.

Lens Anti-Reflection Coatings

AG Optical Systems sources our lenses with a high-quality broadband anti-reflection coating.  Every lens surface in our iDK corrector is coated with a BBAR coating that reflects less than .5% of incident light.  In addition, each lens edge is blackened to minimize the potential for stray light to impact the high-contrast performance of the system.

Stable Optics

The anneal of every AG Optical System mirror blank is checked to ensure the blank is free from internal stress.  Residual internal stress in a mirror can detrimentally affect the figure of the mirror especially as the temperature change through the night.  AG Optical Systems accepts only those blanks with a high quality anneal.

Mirror Coatings

The mirrors in AG Optical Systems telescopes are coated by Ostahowki Optics using their state-of-the-art coating chamber.  The 96% reflectivity enhanced aluminum coatings applied by Ostahowki are extremely bright, clean, and durable.  AG Optical Systems has had optics coated by many different coating companies and, quite simply, Ostahowki's coatings are best in class!

AG Optical Systems iDK primary mirror being coated by Ostahowski Optics Inc.







Please ask our competition how they ensure YOU receive high quality optics in that expensive telescope you are considering.  You will find that cutting corners to save money is industry standard.  Few companies take the measures AG Optical Systems employs to ensure YOU receive only high quality, high performance optics!