Founded in 2006 by Joseph Haberman and Richard Hedrick, PlaneWave Instruments produces high-quality Corrected Dall-Kirkham (CDK) telescopes for the serious amateur astronomer. PlaneWave Instruments offers Dall-Kirkham telescopes in 12.5-inch f/8, 14-inch f/7.2, 17-inch f/6.8, 20-inch f/6.8, 24-inch f/6.8 and 28-inch f/6.5 versions.
Astronomy Products – product reviews: CDK17; Planewave Instruments
For this review, I tested the CDK17, a 17-inch f/6.8 Corrected Dall-Kirkham telescope. I placed this telescope on a Paramount MEII mount and set it up in my friend’s dark backyard observatory twenty miles outside Prince George, British Columbia.
The CDK17 telescope includes a quartz primary mirror and field-flattening two-element corrector lens in the primary baffle tube. In other telescopes employing this design reviewed in the past it was difficult to keep the corrector lens clean in the baffle tube. The designers made it easy to take the corrector lens out in this model, all you do is unscrew the baffle tube and take the lens out.
The CDK17 includes a dual carbon-fiber truss design, with 4 fans blowing across the boundary layer of the surface of the mirror, and 3 cooling fans ejecting air from the back of the telescope.
The CDK17 consists primarily of three parts: an ellipsoidal primary mirror, a spherical secondary mirror, and a lens group.
The telescope we used also included a 3.5-inch Hedrick Focuser, Electronic Focuser Accessory, Paramount MEII, Paramount Versa Plate Accessory, extension bar and two counterweights.
Total price: $38,674
Collimating the CDK17 was very easy and forgiving if you are a little inexact. I was very impressed with the images of stars from corner to corner on a giant 40mm by 40mm CCD 16803 CCD chip. Even when I turned the telescope upside down, the stars remained perfectly focused.
Just take a look at the images I took below. They show no degradation due to coma, astigmatism or field curvature. The fields of stars shot through the CDK17 indicate this is one special telescope.