Credit NASA Astrophotography Copyright Dave Mc Donald 2006

Credit- NASA

Astrophotography Copyright © Dave Mc. Donald 2006

Agenda t. What is astrophotography? t. Basic concepts t. Imagers t. Techniques t. Guiding t. Advanced concepts

What is astrophotography? t. Taking images of the sky (celestial objects or phenomena) t. Can be done any time of the day or night

A typical session… t Choose your subject t Choose your technique t Take the image(s) t Process the image(s) t Display your results t Techniques technical vary from very basic to highly

Why do it? t. Recording events (conjunctions, phases, solar activity, Deep Impact) t. Advancing personal knowledge t. Share your experiences t. Real science ‘A picture paints a thousand words’

Before you take the plunge… t. Decide what you want to do and set clear goals t. Short, t. Where medium and long-term will you be living in 5 years? t. What are you prepared to spend? t. Research, research

How… t. Types t. Basic of imager techniques

Film t. Take a snapshot of the projected sun t. Use an SLR (similar techniques to Digital Cameras – next) t. Film is chosen based on the subject t. Can get very technical (hypered-film etc) t. Is diminishing in popularity with the advent of digital techniques

Digital cameras - Webcams t. Cheap, easy to use, lots of free software for capturing and processing images t. Stunning planetary images t. Very popular

Digital cameras – integral lens t. Dual purpose – astrophotography and holiday snaps t. Popular t. Coming down in price

Digital cameras – SLR’s t. Dual purpose t. Very sensitive t. Expensive t. Can purchase variety of lenses for different applications

Astronomical CCD imagers t. Purpose designed t. Very sensitive t$300 to $40, 000 t. Can be used for science t. Superb deep sky images

Basic Techniques t. Point and click t. Eyepiece projection t. Prime focus t. To guide or not to guide…

Point and click t. Hold your camera and click! t. Works with webcams and digital/film cameras t. Doesn’t work with CCD’s (no lens) t. Can piggy-back your camera on your OTA or use a guiding system to take longer exposures (more on guiding later)

Eyepiece projection t. Hold your camera to the eyepiece and take an image t. Can purchase t-adapters and rings to get the camera lens as close to the eyepiece as possible (to avoid vignetting)

Prime focus t. Your OTA becomes the lens t. Webcams, DSLR’s, CCD’s

Guiding t. The sky moves… t. If you take an image, trailing increases with exposure length (can be an advantage!) t. Can use a camera guiding system t. Can use your mount’s guiding system (piggy-back, projection or prime-focus)

Advanced Concepts t CCD and OTA matching t Collimation t Orthogonality t Polar aligning t Guiding t PEC, mount training t Integrated CCD guiding t Dual CCD guiding t Cooling t Focusing t Filters t Image reduction (darks, bias, flat-field) t Software/hardware t Advanced processing t Photometry/astromet ry t Nova searches

Q&A