Secondary Mirrors – The Heart of Your Telescope

Antares Optics provides ultra precision secondary mirrors, prisms, and custom optical components to your exact specifications. We also carry a custom line of optical fabricating equipment. The exact equipment we use to produce our radical wavefronts that have become our hallmark in the optics industry.

We specialize in low to medium volume production, cost effective prototypes, on time delivery, and a wide selection of materials and configuration.

Complete with a state of the art facility and a top engineering staff, Antares Optics offers excellent quality optics, competitive costs and a fast turnaround time.

Choose which kind of mirror works best for you listed below. 

Minor Axis 1.3
Minor Axis 1.52
Minor Axis 1.83
Minor Axis 2.14
Minor Axis 2.6
Minor Axis 3.1
Minor Axis 3.5
Minor Axis 4.0
Wave PV 1/12


As any amateur astronomer knows, the secondary mirror is one of the most critical components in a reflector telescope. This small, circular mirror sits centered in the optical path, reflecting light from the primary mirror up to the eyepiece or camera. While the primary mirror gathers all the precious photons from celestial objects, the secondary mirror is what allows you to actually view and image those objects.


That’s why it’s so important to choose a high-quality secondary mirror for your reflector telescope. The secondary mirror determines how efficiently light is transferred to your eyepiece, how crisp and sharp the image is across the field of view, and how much contrast and resolution you can achieve on planetary and deep sky objects. An inferior secondary mirror can severely limit the performance of even an excellent primary mirror.


So where do you turn for a top-notch secondary mirror that will give you the maximum performance from your telescope? Look no further than Antares Optics. With decades of experience designing, fabricating, and testing secondary mirrors, Antares Optics is the number one name amateur astronomers trust.


Perfect Parabolas and Ellipsoids


At Antares Optics, we use advanced computer-controlled fabrication machines to grind and polish your secondary mirror to mathematical perfection. We achieve surface accuracies measured in millionths of an inch, far exceeding the precision needed for exact parabolic and elliptical curves. This guarantees maximum light throughput and the sharpest possible focus across the entire mirror surface.


We can create secondary mirrors from 3 inches up to 18 inches in diameter. Our standard wavelengths include the most common 1/10 and 1/12 waves. Or, if you require an unusual curve or wavelength, our skilled optical engineers can produce custom secondary mirrors to your exact specifications.


Built for Collimation and Durability


Our secondary mirrors feature sturdy, thick substrates of low expansion borosilicate or Fused Silica glass. The thicker the substrate, the more inherently stable and resistant to warping from mechanical stress and temperature changes. You’ll spend less time tweaking and collimate your optics.


We also apply high quality, enhanced aluminum coatings that boast reflectivities of 87% to 95% across the visible and near infrared. This maximizes light transmission for brighter, higher contrast views. The enhanced coatings are also more resistant to oxidation and corrosion, maintaining peak reflectivity even after years of use.


Get the Most From Your Primary Mirror


Don’t handicap your excellent primary mirror with a low-grade secondary. Antares Optics secondary mirrors are specifically designed to give you maximum performance by seamlessly matching your particular primary mirror.


For example, our parabolic secondaries are optimized for use with parabolic primaries, providing the best on-axis image quality. Or, for Ritchey–Chrétien scopes, we fabricate the precise elliptical curve required to deliver optimal performance across the entire field of view.


Extensive Testing for Premium Quality


At Antares Optics, we don’t just rely on our mathematical models and computer-guided fabrication. Every secondary mirror is thoroughly tested and validated to certify that the actual optics match the intended design.


We check surface accuracy interferometrically to verify the mirror matches the required conic constant, spherical radius, and higher order terms to incredible precision. The surface smoothness/figure is measured to guarantee diffraction-limited performance. Finally, reflectivity is tested to ensure the coating was applied uniformly and has the correct bandpass for your application.


This exhaustive testing validates that your Antares Optics secondary mirror will perform up to its full potential in your telescope. We stand behind every mirror with our 100% customer satisfaction guarantee.


Choose from Our Wide Selection


Antares Optics maintains a extensive selection of in-stock secondary mirrors. Browse our online catalog to find just the right diameter, minor axis length, and wavelength for your telescope. Common sizes like 1.25”, 1.6″, 2” and 3” secondaries are ready to ship today.


For larger aperture telescopes, we offer ellipsoidal secondaries up to 18 inches across. Just provide your primary mirror’s specifications, and we’ll configure the optimally matched secondary mirror for your system. Don’t see what you need in our catalog? No problem! We can fabricate fully custom secondaries tailored specifically for your telescope.


Unmatched Precision and Accuracy


The key to maximizing your telescope’s performance lies in the extreme precision of the secondary mirror. At Antares Optics, we use advanced computer-controlled grinding and polishing machines to achieve surface accuracies measured in millionths of an inch – far exceeding the precision required for flawless optical surfaces.


Our parabolic secondary mirrors boast surface accuracies of λ/10 waves or better, meaning no more than 1/10 of a wavelength deviation across the entire surface. For visual astronomy at 550 nm wavelength, that translates to a surface accuracy of 0.000055 inches or 55 angstroms. Our ellipsoidal secondaries for Richey-Chretien telescopes achieve even tighter surface accuracies of λ/20 waves or λ/30 waves, down to an incredible 18 angstroms RMS surface figure.


This meticulous polishing results in diffraction-limited mirror performance with strehl ratios over 95% and RMS wavefront errors under 1/20 wave. You’ll enjoy maximized light throughput, pinpoint star images, and sharp views right to the edge of the field of view.


Choose from Solid Substrates


We craft our secondary mirrors from only premium substrate materials that minimize thermal expansion and provide long term stability.


Our most popular option is low expansion borosilicate glass like Pyrex or Duran with a coefficent of thermal expansion of only 3.25 x 10^-6/C. This keeps your optics locked in alignment over a wide temperature range.


For ultimate stability, we offer Fused Silica glass substrates with an ultra-low CTE of just 0.54 x 10^-6/C. Your collimation will stay locked in permanently.


Diameters from 1.25″ to 18″


Antares Optics offers an extensive selection of secondary mirror sizes from small 1.25″ diameter mini-secondaries for short tube refractors all the way up to massive 18″ secondaries for giant observatory telescopes.


Common sizes like 2″, 3″, 4″ and 6″ secondaries are in stock and ready to ship today. We also regularly fabricate secondary mirrors up to 18″ in diameter for custom large aperture telescopes. Just contact us with your needs and we’ll promptly deliver a precision-matched secondary for your system.


Expert Guidance for Your Project


If you need help selecting the proper secondary mirror for your telescope, our knowledgeable technical staff is happy to assist. Just give us a call or send an email. We’ll recommend the best option for your primary mirror, focal ratio, and optical design.


For custom secondary mirror projects, our optical engineers will work closely with you through the design process. We’ll expertly translate your requirements into a precision secondary mirror that delivers outstanding optical performance.


Order with Confidence


Ordering your Antares Optics secondary mirror is quick, easy, and secure on our online store. We accept payment via all major credit cards, PayPal, wire transfers, and purchase orders from established customers. Your order will ship directly from our facility in California, usually within 1-4 business days.


You can trust that your Antares Optics secondary mirror will arrive as ordered, on time, packaged with care to protect the delicate optical surface. We guarantee your complete satisfaction or your money back.


Give Your Telescope the Best – Choose Antares Optics


Don’t compromise the performance of your meticulously crafted primary mirror with a low-quality secondary. Get the most out of your reflector telescope by selecting a precision engineered secondary mirror from Antares Optics. Our decades of optics fabrication experience, rigorous testing, and unmatched expertise ensure you’ll get a secondary mirror that helps you achieve strikingly sharp views and brilliant images.


The secondary mirror makes all the difference when you demand the ultimate in visual and astrophotographic performance from your telescope. Choose the number one name that leading amateur astronomers have relied on for years – Antares Optics. Discover why our secondary mirrors continue to earn rave reviews from the most discerning customers.


Take your telescope to the next level with a parabolic, elliptical, or custom secondary mirror from Antares Optics today!


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