SkyRaider DS10CTEC User Manual
March 17, 2019
SkyRaider DS10CTEC User Manual
Page 133
Taking Flats:
A Flat Field is an image taken of an evenly illuminated object like the dusk sky, or
a special illuminated white card hanging on the wall of the observatory or even
a white T-shirt placed over the telescope.
These images are ideally taken through the telescope:
➢
at the same temperature as your nightly images
➢
through the same filter/s as your nightly work.
➢
Do not change your imaging train (this include adding or
subtracting filters, extenders, reducers, or even rotating the
camera) after you have taken your flats.
➢
with integration times to allow the flat to produce an image that
captures of “noise”, but Flat
images should never bloom, but
should also not be less than a second in integration time.
For precision work, 5 to 30 or more flats at an exposure of not greater than a
couple of seconds. You want an image that shows the faults, not one that is over
exposed. Practice, Practice, and yes, even more practice to get the flats
correct. Each flat will then be averaged together to create a master flat which is
then divided out of your light frame on a pixel by pixel basis.
Visit the following site for before and after images when applying Flats:
http://theworldofastronomy.blogspot.ca/2016/04/astrophoto-flat-field-
illustration.html
