The full easyHDR PRO documentation is available in form of a PDF document. You can get it from the "download" section of this website.
In addition to the PDF documentation you may also find the following articles interesting:
Photography of astronomical objects brings many difficult problems as compared to the photography as most people know. The exposure times can be very long (even tens of minutes) and the lenses, or telescopes used, typically characterize with big focal lengths (thousands of millimeters). This means that the photographed objects must be well guided during the exposure and that the noise (that increases with the exposure time) can spoil the efforts. When we add to this problems with light pollution, quality of optics (even smallest imperfections are clearly visible in case of photographing stars) and the weather, astrophotography appears to be very difficult.
What is more, there are the same problems as in the "normal" photography. One of them is the high dynamic range of the photographed objects - comets, nebulae, galaxies, or the Moon.
A tone mapped HDR photo of a quarter Moon. Visible are both the earthshine and the sunlit lunar surface. This kind of photo cannot be taken without using HDR techniques because of very high luminance ratio. The photo has been processed with easyHDR PRO of a series of 13 photos taken at exposure times ranging from 1/650 sec up to 3.2 sec.
One of the examples is the Orion Nebula (M42). It is very difficult (top shelf class equipment is needed) to take a photo with properly exposed core as well as the outer fine detail.
The sample M42 (Orion Nebula) photos, shown below, were taken by Luke Bellani with Meade DSI Pro 2 astrophotography camera attached to Skywatcher ED80 telescope. The photos were taken at 4, 15, 60 and 340 seconds of exposure. EasyHDR PRO directly imported the FITS image format (that is used by the camera to store image data) along with the exposure parameters, which were used to calculate the exposure values, necessary for true HDR radiance map generation.
4 seconds (EV: -3.91)
15 seconds (EV: -2.00)
60 seconds (EV: 0.00)
340 seconds (EV: 2.50)
Here are the results, using the global only and, additionally the local operator:
Processed: global operator
Processed: local operator
The HDR generation window with the loaded M42 sequence (the "Selectivity" is "Normal" to cut out the noise):
In order to achieve the final result (see below) the default tone mapping settings were slightly modified - gamma was a bit increased as well as the strength of the "Local Contrast" operator. Also the white clipping point on the histogram was moved maximally to the right.
