Patrick
Frank speaking to William Herschel Society 5/12/2014 at BRLSI
Picture of Hersche Nebula looks much better with a modern
digital camera on a smaller telescope, similarly with Orion Nebula.
Ideally use exposure time of an hour in total and at least
several minutes to achieve this.
Examples of objects: Andromeda, Heart and Soul Nebula,
Pheides, M3
Simple formula devised to maximise image quality:
Dark – from quantum temperature effects
on CCD chip
Read – from CCD chip – determines
exposure time
·
Use multiple exposures and integrate to reduce
other terms
Trick
·
Use short exposures of a couple to a few minutes
·
Align them
·
Integrate
Lights - Normal
photo x2 or so
Darks - with
lens cap on to subtract “dark” effect of sensor from integrated image
Flats - use
a uniform background such as a white T-shirt
Bias - rapidly
taken darks with same ISO
“stretching”
image – concentrated on lower end of spectrum to reduce noise to signal ratioe
and increase contrast on interesting objects.
Not sure
what this software package is called.
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