Starguide - A Practical Guide to Astro-Photography

Unlike normal photography, where scenes are photographed in daylight, for example, astrophotography requires a few different approaches. The main challenges here are:

• objects, especially DSO (deep space objects) are very small size
• => this requires long focal lengths
• and they are rather faint:
• => long exposure times even with fast optics (F-Stop < 8.0)
• You need very dark and clear skies 
• => This may require the use of filters to block ambient light from street lamps or cities.
• You have to compensate for the Earth's rotation, depending on the exposure time and focal length 
• => For this, you need a paralactic or azimuthal mount with tracking or guiding capability.
• And you should choose the right file format for the recordings:
• => In any case, a RAW or linear format should be used, preferably and depending on the camera, a format that can store more information about the optical configuration and sky coordinates, such as the .fit, (= standard file format for ASI astro cameras) .fits or .xisf (= standard format for PixInsight image processing) format.

The above-mentioned conditions mean that the simplest, but unfortunately also more expensive, way to take good astrophotographs is to use the Electronically Assisted Astronomy (EAA).

Electronically Assisted Astronomy (EAA) refers to the possibility of observing celestial objects not through eyepieces, but with electronic cameras (today mostly CMOS-based digital single-lens reflex cameras (DSLM) or special astro cameras with additional tracking support by control programs (electronic guides), in order to compensate for design disadvantages of the mounts and thus to achieve very long exposure times that would not be possible without these electronic aids.

The Electronically Assisted Astronomy (EAA) workflow are described in this chapter concentrates on the ASIAIR device manufactured by the ZWO company. The ASIAIR device controls the recording planning, the tracking of the equipment, the recordings themselves, and much more. This is described in the chapter ASIAIR based Workflow.

There are many other HW and SW tools such as Lacerta MGEN-3, N.I.N.A., Sequence Generator (on Windows), APT etc., but these will not be discussed further.

Created with the Personal Edition of HelpNDoc: Effortlessly Publish Your Word Document as an eBook