Amateur Astrophotography

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.