PlaneWave 12.5" Dall Kirkham Astrograph

PlaneWave 12.5" Dall-Kirkham Astrograph

Flat 50 mm field with perfect star images

The PlaneWave Instruments CDK12.5 is a 12.5 inch (0.32 m) f/8 Corrected Dall-Kirkham Astrograph telescope. The telescope has a closed carbon fiber tube, with 3 cooling fans blowing out air from the back of the telescope. The CDK12.5 covers a 52 mm field of view without any field curvature, off-axis coma, or astigmatism. The instrument weight is 46 lbs and comes standard with the large capacity 2.75 inch Hedrick focuser.

The CDK (Corrected Dall-Kirkham) optical design is an innovative solution for unsurpassed astroimaging quality at an affordable price. The CDK telescope design provides excellent imaging with large format CCD cameras while remaining superb for visual use. The CDK design far exceeds the off-axis performance of most commercial telescope designs including the Ritchey-Chrétien design.

This no-compromise design is unique in making the optical alignment forgiving and collimation very easy. This guarantees the user the best possible performance from the telescope. The end result at the image plane of the CDK design is no off-axis coma, no off-axis astigmatism, perfectly flat field (no off-axis defocus). The CDK design will give you pinpoint stars from the center to the corner of the field of view.

Standard Features

Carbon Fiber Tube Design: Minimizes thermal expansion which causes focus shift with changes in temperature

Dovetail expansion joint: Allows for the difference in thermal expansion between carbon fiber and aluminum. The expansion joint allows the aluminum dovetail expand and contract without stressing the carbon fiber lower truss

2.75 inch Hedrick Focuser: Heavy duty no-slip focuser. The focus tube runs on 5 bearings and is driven by a leadscrew so there is no chance of slipping. Focus may be automated through a computer using PlaneWave´s EFA Kit add-on. The draw tube travel is 1.3 inch.

Cooling Fans: Three fans blow out of the optical tube pulling air though the telescope and by the primary mirror. This helps the telescope to reach thermal equilibrium quickly. The fans are controlled by a switch on the optical tube or can be conrolled by a computer if the optional Electronic Focus Accessory (EFA Kit) is purchased.

Optional Accessories

2.75" to 2" Adapter: The adapter steps the 2.75" opening of the focuser down to 2" for standard 2" accessories. The BA1323850 also adds some additional spacing to optimize the use of a 2" diagonal so focus is reached with most eyepieces. The adapter is linked in the accessories section, as is a star diagonal mirror.

M68 Adapter: You can use the M68 adapter BA1323842 to attach M68 accessories to the CDK125. The adapter is linked below.

0.66x Reducer: The focal reducer BA1326012 reduces the focal length and thus increases the field of view, but the shortened exposure time of 44% for two-dimensional objects is also helpful. The reducer is also linked.

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin

Downloads

The manufacturer provides instructions, drawings and software for many of its products. The files can be accessed centrally from his download page.

Telescope OTA

2.75" motorised focuser - provides 1.3" (3.3 cm) of focus travel and requires 3" (7.6 cm) of back focus. Requires EFA kit BA1329012, sold separately.

Built-in dew prevention heaters - the heaters on the primary and secondary mirrors require Delta-T Controller BA1329110 for Planewave telescopes, sold separately, with pre-installed wiring for the heater.

OTA cover - to protect the primary mirror and the inside of the optical tube

Dovetail bar Losmandy style

Flash Drive - contains software and instructions for collimation and primary to secondary mirror spacing.

Tool kit (PlaneWave #5812A35) - standard Allen key (for European orders only)

Soft cover for the secondary mirror

12 V AC adapter

No adapter is supplied for the familiar 2" and M68 connections, but there is one for each in the accessory links.

Shipping box BA1323512 is additionally required.

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin

Safety informations: PDF Download