Is a field flattener the same as a coma corrector?

Is a field flattener the same as a coma corrector?

Often in the form of an accessory, like a coma corrector that when added to a newtonian corrects it’s coma, or a field flattener that when added to an SCT or to a refractor corrects it’s field curvature. Some times, the corrections are built-in the scope.

What is a coma corrector telescope?

The photo/visual Astro-Tech Coma Corrector is a three-part 2″ auxiliary lens system that drastically reduces the coma and the curvature of field in a fast focal ratio Newtonian reflector during visual observing and astrophotography. It essentially makes an f/4 telescope perform like an f/8 in terms of coma.

Does a coma corrector change focal length?

However, in making that correction they may change the effective focal length of the telescope, but that’s generally a very small change (a few percent) and it’s largely just a side effect from the correctors intended purpose (which is to remove the coma).

What does a field flattener do?

Field flattener lenses in binoculars improve edge sharpness and lower the distortion. Field flattener lenses counteract the Petzval field curvature of an optical system. In other words, the function of a field flattener lens is to counter the field-angle dependence of the focal length of a system.

What does a reducer flattener do?

Refractor telescopes are made to be used visually with an eyepiece. To use a telescope for photography an optical device is needed to convert your telescope from a visual instrument to a photographic camera lens. This optical device is a field flattener (or reducer/flattener).

What is advanced coma free optics?

“ACF” stands for “Advanced Coma-Free.” Coma is an opti- cal defect that distorts off-axis images (those far from the field of view’s center). The LX90-ACF comes equipped with multicoated optics, a GPS receiver, two finder scopes, Level North Technology, and the AutoStar controller with Auto- Align software.

How does a Barlow affect Backfocus?

A side effect of Barlow lenses is the increase in back focus (the distance between the telescope to the end of the optical setup). Due to their design, some telescopes like Newtonians/reflectors, have very little back focus. Barlow lenses can help you increase it.

Is a field flattener needed?

To use a telescope for photography an optical device is needed to convert your telescope from a visual instrument to a photographic camera lens. This optical device is a field flattener (or reducer/flattener). Without a field flattener stars that are not in the center will appear distorted. Spacing is critical.

Is a field flattener necessary?