Orion optics UK ODK16 16 inch F6.8 Astrograph OTA

The full range is based on a focal ratio of f6.8, fast enough for some superb deep sky photo-visual use and, still have enough focal length for high resolution planetary work both visual and CCD applications.

The tube is constructed from Carbon Fibre sandwich design. Very, very strong to avoid flexing and, zero expansion to ensure the focal plane does not change over long photographic exposures. Being an open tube design and very short, cool down times are remarkably fast.

To assist cool down of the telescope, each model is fitted with three fans, all positioned behind the primary mirror.

Exact focusing across the ODK range is achieved with our own Precision ACU-3S 3" Crayford Focuser featuring a 10:1 reduction drive included as standard - focuser pictured right. Good images need good optics, all fitted in reliable, stable and precise engineering.

Customers with heavier than normal (4kg+) CCD equipment can add features to the ODK tube to enhance stability.

To produce the photo-visual wide, flat field of the ODK range, we have designed and fitted integrally, a corrector lens system. which ensure both colour correction, coma and spherical aberration are optimised to achieve almost a perfect photographic and visual field. Adequate back focus allows all modern CCD cameras to be used with auxiliary equipment. Multi layer anti reflection coatings are applied to all lens surfaces to maintain brighter images.

CNC machined mono construction secondary spider and trim ensures stability in collimation. Our unique collimation adjustment system enables perfect collimation of the secondary mirror to be achieved, quickly and reliably.

The ODK16 is in use world wide by amateurs and professionals alike.

Viewing the spot diagrams and other graphic information will show you just how good the ODK16 presents it's outstanding specification. As wil all the ODK models we don't skimp by using just 2 lens elements in the corrector system, we could, but we know from extensive computer designs that there is a real need for 3 elements to give a wider, flatter field. It costs quite a bit more to have this extra lens but, if you compare like with like spot diagrams of an ODK with a similar model on the market, the difference is noticeable and, it's there for every image you take or visual observation you make, you have the best optical performance available in an Optimised Dall Kirkham, anywhere.

We recommend that ODK16 are observatory mounted, ideally on a Paramount but, other mounts are available and we will be pleased to quote you for these if we do not offer them here on our web site.