About this product
Part Number: 69900
Japanese made Borg 90FL f/4 drawtube astrograph features a premium quality Fluorite objective from Canon with 80mm tube diameter.
The 'drawtube' package features a drawtube for easier focusing and doesn't include the M57 camera rotator found in the regular astrograph package. To use visually you can simply remove the reducer and replace with a 2" eyepiece holder available separately such as 7504.
The addition of the drawtube makes this useful for use as a telephoto lens for wildlife photograph as it allows focusing at various distances - the pure astrograph set is designed primarily for focusing at infinity.
Includes a Borg Helical focuser for precise dependable focusing.
Modular Borg design allows you to reconfigure the scope for visual observing or to disassemble it for ultra portability.
- Aperture: 90mm
- Focal length: 360mm
- F-ratio: 4
- Lens configuration: 6 elements in 5 groups
- Coating: Fully multi-coated
- Physical length: 400mm
- Tube diameter: 80mm
- Weight: 1.9kg
- Filter: 82mm (front cap) & 48mm in front of reducer
- Parts included: 2591, 7101, 7780, 7790, 7835 & 7872
90mm Fluorite Objective
- Focal length : 500mm
- F-ratio : 5.6
- Weight : 950g
- Length : 145mm
Precision helical focuser
- Light path: 63mm to 82mm
- OD: 77mm
- ID: 56mm
- Weight: 320g
- Four-element reducer
- Back focus distance: 60mm
- Image coverage: Full frame
- Objective side interface: M57 male
- Camera side interface: M57 female
Telescope Field of View Simulator
What's in the box
- 2591 - 90FL Flourite Objective
- 7101 - 80mm Dia. 100mm Tube
- 7780 - Drawtube Holder DX
- 7790 - Drawtube DX
- 7835 - Helical Focuser M
- 7872 - 0.72x Quadruplet Reducer
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