Handbook for the TRIUS PRO-825C Issue 1 September 2020
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check the ‘Autosave Image’ checkbox near the bottom of the window. If you now
click on ‘Take Picture’ the automatic sequence will begin and will not stop until you
press a computer key. The images will be saved in FITs format with sequential
names such as ‘Img23, Img24….’ and will be found in the ‘Autosave’ directory (or a
sub- directory of Autosave, set up in the program defaults menu).
The exposure time needed for good planetary images is such that the image
histogram has a peak value at around 200 and does not extend much above 220
(Ignore the major peak near zero, due to the dark background). If you use too short
an exposure time, the image noise level will be increased, and if too long a time is
used you will saturate the highlights and cause white patches on the image. With
the recommended focal length, Jupiter and Mars will both need an exposure time
of between
0.1 and 1 seconds and Saturn will need between 0.5 and 2 seconds.
Processing a planetary image:
Planetary images have one major advantage over deep sky images, when you come
to process them – they are MUCH brighter, with a correspondingly better signal to
noise ratio. This means that aggressive sharpening filters may be used without
making the result look very noisy and so some of the effects of poor seeing can be
neutralised.
A raw image
