Page 41 - DENOISE projects professional - User Manual

Use the correction radius to select the pixel area in which the correction should take
place.
A radius of 1 uses an area of 1 pixel, so in total 3x3 pixels, a radius generates a
correction matrix of 7x7 pixels.
(d) Colour correction
Colour correction is option for reducing so-called colour clouds. Colour clouds are very
soft and widespread colour noise.
Note: Often in astrophotography many dark frame shots will be taken, which are then
summed up into a “Master dark”. Definitely 50, if not more, dark frame shots can be
taken to be assembled into the master dark.
The rule of thumb is that more dark frames than normally exposed shots should be
taken, so that the noise in the master dark is less than that in the master light.
DENOISE projects professional can directly assemble the sequence of dark frames for
you with the batch processing function.

Flat Frames – and what are they?
Flat frames are exposures of a uniform surface showing sensor spots and vignetting. It is
thereby important to take the flat frames with the same optic settings (filter, lens etc.)
as the shots of the actual subject.
The flat frames will help to remove light distortions like the camera’s vignetting and
caught dust (sensor spots).
It is also practice, like with dark frames, to take many shots that can then be assembled
into a “master flat”.
The “stacking image sequence” function has a special modus for flat frames, just like it
does for dark frames.

In the original image on the left, a light interference can be seen in the upper left half.
The middle image is the flat frame (master flat) – which also clearly shows the
shadowing defect in the brightness.

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