To give a new dimension to astrophotographers dedicated to deep sky photography, we introduce the AG (Advanced Astrographs) telescopes from ORION OPTICS UK. These are tubes constructed with a carbon fiber reinforcement - very rigid to prevent flexing and with virtually zero expansion or dilation coefficients to ensure that the focal plane does not vary throughout the duration of a long photographic exposure.
To help thermally acclimatize the telescope, each model is equipped with three fans, all positioned downstream of the primary mirror to create a laminar flow that accelerates the acclimatization process without generating disturbances.
Very precise focusing is possible through the use of the new 3" Crayford focuser that is standard on all models. Oversized bearings in strategic positions distribute the weight of the focusing tube, or corrector, and any cameras that may be attached. In this way, no bending of the optical train is achieved. A 10:1 reducer system on the focuser is included as standard, and as an additional option, a motorized electronic system can be added to control the speed of the focuser.
To achieve a remarkable flat photographic field, ORION OPTICS UK has designed and manufactured the Corrected Field Flattener (CFF). This design is based on the Wynne corrector, very frequently used in similar telescopes. ORION OPTICS UK has taken this design a step further by improving the performance offered over the entire wide field of view.
Stars remain incredibly small and regular across the wide field of view captured. The use of specialized ED glass ensures the absence of chromatic aberration and coma, and spherical aberration is optimized to near perfect image over the entire field of view. The backfocus of ORION OPTICS UK AG telescopes is 79mm.
This allows the use of virtually 100% of the CCD cameras currently in use, using the appropriate adapters. When selecting a camera and adapter accessories, ensure that your CCD will be placed at a maximum of 79mm (plus minus 1mm) away from the corrector lens. Otherwise, the full potential of the corrected system will not be achieved. The CFF is treated for low light loss through absorption and with anti-reflection treatments to keep images bright.
The AGs come equipped with OC2 focusers, designed to accept up to 4Kg of load. In cases of higher weight load, ORION OPTICS UK allows the selection of machined stability ring type attachments to allow for greater load capacity.
The secondary spider and secondary support are computer numerical control machined to ensure collimation stability. ORION OPTICS UK 's unique collimation adjustment system allows us to quickly and easily achieve perfect collimation of the secondary mirror.
The main mirror is placed in a newly computer optimized suspension cell with 9 attachment points. This allows to balance the mass of the mirror over a much larger area and thus achieve sharper and more defined images.
In summary, we can say that ORION OPTICS UK AG astrographs are excellent for deep sky work. The optical quality, engineering design and ORION OPTICS UK 's own quality control measures ensure some of the most exquisite imaging ever achieved with amateur equipment.
Technical Specifications:
Primary Diameter: 250mm
Focal Length: 950mm
Focal Ratio: F3.8
Backfocus: 79mm
Tube weight: 12Kg
Tube diameter: 300mm
Tube length: 810mm
Material used: Carbon fiber reinforced
Secondary diameter: 100mm
Primary cell: cNC machined with 9 suspension points
Focuser: 3" Crayford with 10:1 double speed reduction
Corrector Design: 4 ED (Low Dispersion) Lenses
Flat field size: 50mm
Spot size on optical axis: 3.0µ
Spot size at end of field: 7.2µ
Mirror/tube cooling: 3 controllable fans
Mounting method: Aluminum dovetail rings and dovetail designed under numerical control
