PlaneWave Instruments was founded in 2006 by Richard Hedrick and Joseph Haberman, two former telescope engineers at Celestron, one of the largest telescope manufacturer worldwide. Richard Hedrick brings over 21 years of telescope design experience. As former Chief Technology Officer and previous owner of Celestron he was responsible for developing Celestron’s award winning Schmidt-Cassegrain computerized telescopes. Joseph Haberman has over 20 years of experience in telescope design and worked at Celestron as an optical engineer and master optician. Getting a product like the CDK into the hand of serious imagers and amateur astronomers has been a shared vision of Hedrick and Haberman for many years. PlaneWave Instruments is committed to providing observatory-class products for serious astronomers at an unprecedented value.

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CDK Telescopes

The Corrected Dall-Kirkham (CDK) telescope is based on an optical design developed by Dave Rowe. The goal of the design is to make an affordable astrographic telescope with a large enough imaging plane to take advantage of the large format CCD cameras of today. Most telescope images degrade as you move off-axis from either coma, off-axis astigmatism, or field curvature. The CDK design suffers from none of these problems. The CDK is coma free, has no off-axis astigmatism, and has a flat field. The design is a simple and elegant solution to the problems posed above. The CDK consists of three components: an ellipsoidal primary mirror, a spherical secondary mirror and a lens group. All these components are optimized to work in concert in order to create superb pinpoint stars across the entire 52mm image plane.

The CDK design tackles the off-axis coma problem by integrating a pair of correcting lenses into a two mirror design. The beauty is that this design also corrects for astigmatism and field curvature. Because the lenses are relatively close to the focal plane and because these lenses work together as a doublet, there is no chromatic aberration. The CDK offers a wide aberration-free, flat field of view that allows the user to take full advantage of the very large imaging chip cameras in the market place today.

Having an aberration free telescope design means nothing if the optics cannot be aligned properly. The secondary mirror of the CDK design is spherical. It has no optical axis and so the centering tolerance of the CDK secondary mirror is comparatively huge. With the help of some very simple tools, the CDK user will be able to set the secondary spacing, collimate the optics and begin enjoying the full performance potential the instrument has to offer within a few minutes.

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CDK Alt-Az with Nasmyth Focus

An alt/az mount is inherently more stable than an equatorial mount as there is no cantilevered mass, nor are there any large counterweight protruding that are very dangerous in a public observatory. The mass it takes to make a rigid Alt/Az mount is substantially leading to cost savings. There is no dealing with balance changes as you cross the meridian or meridian flips that German Equatorial Mounts have to deal with. You can image from horizon to horizon continuously if desired. Alt/Az is more intuitive to use and there is no polar alignment needed. Besides, it is the way the big boys do it.

The Nasmyth Focus is along the altitude axis so there are virtually no balancing issue as you change out equipment. In addition the CDK700 comes standard with a field rotator / field framer. Direct Drive motors means that there are no gears which cause backlash and periodic error. With the high resolution encoders providing the feedback for the direct drive motors, not only will the telescope track without periodic error or have any backlash at all, but the mount will be able to counter against wind gusts. The direct drive motors can move the telescope at incredible speeds for tracking satellites or just to minimize target acquisition time.

The CDK optical design produces a flat, coma free and astigmatic free field of view. Since the secondary mirror is spherical, centering is very forgiving, which means it is easy to get the telescope optics aligned for optimum performance, this is not the case for most high-end astrographs. The end result at the image plane of the CDK design is no off-axis coma, no off-axis astigmatism, and a perfectly flat field, all the way out to the edge of a 50mm image circle. All this means, the stars will be pinpoints from the center of the field of view out to the corner of the field of view.

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Ascension 200 Mounts

The Ascension 200 and the Ascension 200HR German Equatorial Mounts. Both mounts are designed to give peerless performance with up to 275 pounds of payload. Both use 360-tooth, 12.1 inch diameter RA and DEC gears, have built-in homing sensors on each axis, and are supplied with permanent periodic error correction and a hand pad. The Ascension 200HR is additionally equipped with state-of-the-art high-resolution encoders on each axis that correct for residual mechanical errors including PE and DEC backlash, thereby enabling long, unguided exposures.

The Ascension 200 and 200HR are excellent mounts for both permanent observatories and portable applications. Modularity makes the mount easily transportable for field work, breaking down into three components. The heaviest component is 96 pounds. The PlaneWave Instruments Ascension 200 and 200HR mounts are beautifully machined and finished, featuring powder-coated aluminum with stainless steel complements.