What does an off-axis guider do?
An off-axis guider is an optical device used in astronomy and astrophotography to maintain alignment of a telescope's optics with a particular set of stars or celestial objects. The device works by providing continuous feedback that allows the user to correct any misalignments before taking a long-exposure photograph. Off-axis guiders are incredibly useful for creating sharp, clear images, as they allow for precise tracking of celestial objects throughout the duration of an observation or imaging session.
Is an off-axis guider better than a guide scope?
Both an off-axis guider and a guide scope can be great tools for astrophotography, depending on the user's needs. The main difference is that an off-axis guider uses a separate camera to track stars or celestial objects, whereas a guide scope uses the same telescope optics as the imaging device. In general, an off-axis guider offers more precise tracking of whatever object is being imaged, as well as faster response times and less vibration. However, they can also be more expensive and require additional equipment like a computer-controlled mount. Ultimately, which tool is better depends on the user's goals and preferences.
What does an on-axis guider do?
An on-axis guider is a specialized device used in astrophotography to maintain alignment between the telescope optics and the celestial objects being imaged. Unlike an off-axis guider, which uses a separate camera to track stars or other celestial objects, an on-axis guider uses the same eyepiece or imaging device as the telescope. The on-axis system works by tracking a small area of the night sky and calculating misalignments rapidly, making corrections as needed. This type of guider is best for when precise tracking of wide field objects is necessary. It also offers some advantages over off-axis guiding, such as faster response times and less vibration.