Teeter's Telescopes Guarantee

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Telescope Performance Guarantee

All Planet-Killer Truss-Dobsonians and Truss Conversions are tested both optically and mechanically before shipment or delivery to each customer. Scopes are tested a minimum of two nights of average or better seeing conditions with above average transparency. A range of magnifications are used to ensure that the scope focuses brilliantly. Eyepieces yielding 50x to 60x per inch of aperture are used to "dial-in" the collimation, square the focuser and confirm no gross defects in either the primary or secondary mirrors. Scope rigidity is also checked using laser-methods to determine if there is any change in collimation as the scope is moved through altitude and azimuth motions. If so, the scope goes back into the work shop and is reworked until collimation is rock steady from horizon to horizon.

*Note: For "blind builds" where the customer does not supply us with their optics, we can make no guarantees with regard to balance of the telescope or to proper focus-point location. We try our best but there is nothing like having the actual optics within the Truss structure to find and remedy any and all kinks. Please notify us before placing your order if you do not plan to send in your optics or have us purchase optics directly. Thanks - Teeter's Telescopes staff.

Primary and Secondary Mirror Guarantees

R.F. Royce of Royce Optics (supplier of our 8" and 10" mirrors) has this to say about their optical guarantees: "Wavefront accuracy having an RMS of .032 and a Strehl Ratio of .96 or better at 587 nm for apertures up to 10". Mirrors up to 16" to have a wavefront accuracy having an RMS of .036 and a Strehl Ratio of .95 or better. Primary surface ripple below discernable amount in star test."

Steve Swayze at Swayze Optical (suppliers of our 12.5" to 20" mirrors) has this to say about their optical guarantees: "The best possible surface smoothness and accurate correction are obtained through a series of tests. For final figuring we use the Ross Null Test which employs a certified reference lens. Steve has proven these methods by his years of experience and the many mirrors he has made. Since the Ross Null Test is a null test, we have no zone measurements or certifications available. Your mirror is figured to a smooth null. Experience in the field has shown that this method provides exceptional results, and outstanding views. Our mirrors are well within the diffraction-limited envelope. No inaccurate wave front claims or misleading expectations are made. Your satisfaction is guaranteed."

Ed Stevens of Stevens Optical (supplier of our 10" f/6, 12.5" f/5 and 16" f/4.5 mirrors) has this to say about his optical guarantees: "I am able to produce a mirror with an extremely smooth, zone free surface. High contrast images and pinpoint stars are expected at the eyepiece as well as the ability to achieve a minimum of 50x per inch of aperture on nights of excellent seeing. The images are crisp, clear, bright and detailed. You will not be disappointed with a mirror from Stevens Optical."

Antares Optics (supplier of all our of secondary mirror mirrors) has this to say about their optical guarantees: "All Antares Optics secondary mirrors are manufactured to an ultra radical surface accuracy. Each piece is tested before and after the coating process. By using Standard reference surfaces, and a 1/30 wave PV Dynaflect reference surface, our Zygo GPI interferometers can measure highly reflective coated surfaces. Giving you certifiable proof of it's flatness, before and after it has been coated."