PlaneWave Instruments is a company making telescopes for amateur and professional astronomers. They make CDK (Corrected Dall-Kirkham), IRDK (Infrared Dall-Kirkham), and RC (Ritchey-Chretien) telescopes as well as imaging and observatory class mounts.
The company also makes high-end telescopes that are optimized for astrophotography. They offer a product line with stable pricing, available to amateurs, educational institutions, and the scientific community.
Table of Contents
Who is PlaneWave Instruments and what are the different models of PlaneWave Telescopes?
PlaneWave telescopes are professional-grade, high-performance astrophotography equipment that is used for astronomy, spectroscopy, and other scientific research. They are designed and engineered to provide high-end performance and exceptional astronomical imaging for a wide range of users, from amateurs to professionals.
Founded by former Celestron engineers Richard Hedrick and Joseph Haberman, PlaneWave Instruments produces some of the finest observatory-class products for serious astronomers and professional researchers. Their innovative Corrected Dall-Kirkham (CDK) telescope optical system works with large-format CCD and CMOS cameras to capture sharp, detailed images of the sky.
This groundbreaking optical system is incorporated into many of the CDK and Richey-Chretien telescopes offered by PlaneWave Instruments, adding a new dimension to professional scientific investigations of the cosmos. In addition, PlaneWave offers a variety of other telescopes for visual observation and small-scale research applications that are ideal for a variety of users.
CDK Features
The corrective optics system found in all PlaneWave Instruments CDK telescopes were developed to provide sharp, detailed images of the sky without field curvature, off-axis coma, or astigmatism that can interfere with astrophotography and image quality. The CDK optical design is based on the physics of light, and is optimized for a wide array of observing conditions.
Carbon Fiber Truss Icon
The trusses on the CDK17, 20 and 24 telescopes are made of carbon fiber to minimize problems of thermal expansion that can cause focus shift with changes in ambient temperature. This material reaches ambient temperatures quickly and is extremely lightweight and rigid to ensure that excellent imaging data is produced.
PlaneWave also uses digital 3D printing technology to produce lightweight baffle tubes with precision positioned internal stray light baffles that help reduce vignetting and maximize image contrast. These baffles can significantly improve astrophysics results and are critical for reducing the effects of atmospheric haze on the astronomical imaging process.
L-Series Direct Drive Mount Icon
PlaneWave’s innovative and revered L-Series direct drive mount is the standard for observatory class telescopes. It is a high-quality, fully automated alt-azimuth telescope with direct-drive motors and integrated encoders that deliver zero backlash or periodic error. These innovative features make this telescope a true workhorse for any astronomical project.
CDK (Corrected Dall-Kirkham) Telescopes
The CDK (Corrected Dall-Kirkham) is a revolutionary telescope design that provides astronomers with a large image circle free of coma, off-axis astigmatism and field curvature. It also produces a flat field that is ideal for imaging with the largest CCD sensors available today.
This new optical design was created by a team of Celestron employees who wanted to build large telescopes that would be affordable and easy to use. It was developed by David Rowe and is based on the standard Dall-Kirkham design but adds two corrective lenses that address off-axis aberrations.
Many telescopes suffer from off-axis coma, off-axis astigmatism, or curvature of field. These problems result in a lower quality of imaging and may even cause the images to be blurry or unusable. This is because off-axis aberrations can affect the way the image is reflected by the primary and secondary mirrors, leading to the loss of image clarity.
Another problem with most telescopes is that they are hard to collimate properly. This is especially true with Ritchey-Chretien telescopes, which are notoriously difficult to align. This can make it impossible to take advantage of the full performance of these telescopes, reducing the usefulness of their optics for astronomical observation.
In the CDK, alignment is forgiving and easily achievable due to the design of the spherical secondary mirror. This makes the design a much more future-proof solution than many other astrographs, which are often quite difficult to collimate when fast cameras and adaptive optics become available.
The primary mirror in the CDK is conical, which allows it to shed heat more quickly and easily than a conventional cylindrical mirror. Three cooling fans are positioned inside the telescope to exhaust hot air that collects on the back of the mirror, which helps the mirror reach thermal equilibrium more quickly and keeps the images clear.
In addition, the CDK12.5 is constructed from carbon fiber that has a significantly lower thermal expansion rate than traditional metals like aluminum. This enables it to maintain a stable temperature throughout the night and reduces the need for refocussing. The CDK12.5 also uses quartz mirrors, which are much more thermally stable than the typical Pyrex mirrors found on many telescopes.
IRDK (Infrared Dall-Kirkham) Telescopes
PlaneWave Instruments sells IRDK (Infrared Dall-Kirkham) telescopes to astronomers who need infrared optimized imaging optics. These telescopes feature a Dall-Kirkham optical design with coatings that are optimized to transmit in infrared wavelengths. The coatings are protected gold that provides better than 98% reflectivity from 0.65 microns (650 nm) to 5 microns (5000 nm).
These telescopes are diffraction limited across a 20mm image circle at the focal plane and can be ordered in 24′′, 20′′ or 14′′ apertures. All IRDK telescopes are built with quartz optics figured by a master optician to provide a flat field of view and accurate collimation.
All IRDK telescopes are available with an optional Electronic Focus Accessory that allows you to manually adjust your focus using a computer-controlled fan blowing air through the optical tube and over the primary mirror. This helps your telescope achieve thermal equilibrium quickly and reduces the chance of focusing problems.
The IRDK is a modified Dall-Kirkham design that offers several advantages over the Ritchey-Chretien telescope. The spherical secondary mirror is less prone to distortion than the hyperbolic secondary of the Ritchey-Chretien design. This is particularly important if you are using a spherical camera with a CCD chip that can be shifted or aligned on different lines of sight.
This modification also removes the need for a corrective lens to compensate for chromatic aberration and eliminates the coma effect in the imaging zone. The result is a perfectly flat field of view that can be used to capture high-contrast, sharp stars in a wide range of fields.
In addition, this design enables us to offer a wider range of field diameters than are possible with the Ritchey-Chretien design. We can also manufacture RC telescopes with an image circle of 52mm, which is equivalent to the diagonal of a modern full frame DSLR or a new generation of CCD chips that will soon be on the market at affordable prices.
Alluna Optics is committed to manufacturing a telescope that is universal and future-proof. That means a telescope that is designed and manufactured to last for years to come, even when used for astronomical research and spectrographs.
RC (Ritchey-Chretien) Telescopes
The Ritchey-Chretien telescope is a type of Cassegrain telescope with a hyperbolic primary and secondary mirror. This optical design eliminates the problems of coma and spectral dispersion suffered by conventional Schmidt-Cassegrain telescopes, while delivering a wider field of view. RCs are a popular choice for astrophotographers because they can capture stellar images that are free of chromatic aberration.
The iOptron Photron RC6 (Ritchey-Chretien) Telescope is an advanced astrophotography imaging instrument with low thermal expansion quartz optics. The RC6 offers superb coma and spherical aberration free results for true color imaging. This astronomical telescope is ideal for use with astro-cameras up to an APS-C sensor size.
This telescope features precise figured optics and baffled tubes to provide superior contrast. It also features a dual-speed focuser to securely hold a camera or accessories in place, and rugged construction with a carbon fiber body.
These telescopes are great for astrophotography because they have wide, flat fields of view. They are also easy to use and require less adjusting than other types of telescopes. The RC6 is an excellent choice for both beginners and advanced astrophotographers.
PlaneWave Instruments sells several different models of RC telescopes. They include the PlaneWave PW700-RC Ritchey-Chretien Automated Alt/Az Telescope System, which is perfect for astrophotography. This RC telescope can be used with an astronomical camera without the need for a corrector, which reduces exposure times and allows you to shoot longer star-filled astro-images.
Another model of RC telescope that is popular with astrophotographers is the Astro-Tech AT10RCF. This scope is the first large aperture true Ritchey-Chretien astrograph offered at an affordable price by a U.S. manufacturer. It has all the premium features of much more expensive RCs, including quartz mirrors, a carbon fiber body, and a precision dual-speed focuser.
RC telescopes are often used as deep-sky imagers, but they are not the best choice for visual observation. However, the RC telescope is very useful for imaging smaller deep-sky objects such as galaxies and small nebulae. Many professional astronomers and observatories use this kind of telescope for their research. This is because RC telescopes produce better images in dark sky settings than traditional reflectors and Schmidt-Cassegrain telescopes.
Additional References about PlaneWave Telescopes
This is a list of websites providing information about Planewave Instruments, Corrected Dall-Kirkham (CDK) telescopes, and more:
- Planewave Instruments website – https://planewave.com/
- CDK Telescopes design – https://www.baader-planetarium.com/en/blog/cdk-optical-design/
- Astronomy Technology Today’s article on the Planewave PW1000 1-m class telescope – https://astronomytechnologytoday.com/2017/05/31/planewave-instruments-enters-one-meter-observatory-grade-telescope-class-with-pw-1000/
- YouTube video of the Planewave CDK700 telescope with HartSCI ClearStar Adaptive Optics – https://youtu.be/yWf6YBgkGG0
- An article about PlaneWave Instruments Adaptive Optics – https://astronomytechnologytoday.com/2022/08/14/planewave-instruments-adaptive-optics/
- An Optodir Market article about the different types of telescope mounts – https://www.optodir.com/telescope-mount-types/
