The coma corrector is a very important accessory for all NEWTON telescopes with an aperture ratio between f/3.5 and f/6, especially for photographic use.
With this corrector, you can correct the field even with cameras with large sensors up to full frame ("FULL FRAME").
On the inside (camera side) there is a 2" filter thread, e.g. for use with a narrow band filter or a light pollution filter.
The Artesky coma corrector also reduces the focal length of your Newtonian telescope:
For example, a Newtonian with a native focal length of f/4 is reduced to a resulting focal length of f/3.4. This significantly shortens the exposure times and also results in a fully illuminated field of view - ideal for shooting with full-frame DSLR cameras!
Compatible with Newtonian telescopes between 150 mm and 300 mm aperture with an aperture ratio between f/3.5 and f/6.
Factor: 0.85x
Field: Full Frame
Optical elements: 4 optical elements with multiple coating
Outer diameter: 76.3 mm (3")
Back focus: 55 mm
Total length of the corrector: 119.81 mm
Weight: 0.89 kg
What is coma and what causes it?
Coma is an optical aberration that derives its name from its classic comet-like appearance (coma = tail of a comet).
Coma occurs when the object being imaged (e.g. a star) is moved sideways relative to the axis of the system by a certain angle. The rays that pass through the periphery of the optical axis are focused at a different point on the axis. This gives the star a "tail" and makes it look like a small hook. This effect occurs mainly in fast Newtonian telescopes at the edge of the field of view. A ray of light passing through the lens at a certain distance from the centre is focused in a ring shape on the focal plane. The superimposition of these different rings creates a V-shape similar to the tail ("coma") of a comet.
As with spherical aberration in refracting telescopes, coma can be reduced or even completely eliminated by using suitable coma correctors for the optical system in question.
