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Astrophotography is Fun!

Astrophotography is Fun!. Astrophotography. Amy Eisin, with pictures by club members February 25, 2002. Overview. Camera Hardware Film Exposures Lens Telescope. Camera Hardware. Manual vs. Automatic T-ring (goes on camera) T-mount (telescope adapter)

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Astrophotography is Fun!

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  1. Astrophotography is Fun!

  2. Astrophotography Amy Eisin, with pictures by club members February 25, 2002

  3. Overview • Camera Hardware • Film • Exposures • Lens • Telescope

  4. Camera Hardware • Manual vs. Automatic • T-ring (goes on camera) • T-mount (telescope adapter) • ISO exposure settings, cable release • Size of film 35mm, Medium Format

  5. Film • 35mm negative • 35mm slide • Color • Black and White • ISO rated speed • “Push” processing

  6. Exposures • Final image depends on film speed, focal ratio, and exposure time • Film speed • Higher ISO numbers give brighter images • Focal ratio • Lower “f” numbers give brighter images • f/5 is brighter than f/10 • Exposure time • Longer exposures give brighter images

  7. Film Differences • Color reproduction • Grain • Sensitivity • 4 M42 shots, different films, exposures

  8. Film Grain • Film has inherent “grain” to it • Faster films (higher ISO) are usually grainier • Pushing film makes it grainier, sometimes much grainier

  9. Camera Lens • Lens aperture • Focal ratio • Focal length + image scale • Lens hood, prevent reflections

  10. Photography methods • Tripod • Barn Door (poor man’s clock drive) • Piggyback • Afocal (camera lens on camera focused at infinity, held near telescope eyepiece) • Prime focus (with telescope) • Eyepiece Projection (high magnification, for planets, very hard)

  11. Tripod Photos • Max exposure of 20 seconds before stars trail on a typical lens (not zoom) • Moon shot, right before sunrise, from Haleakala volcano, Maui • 1 sec exposure

  12. Piggyback Orion Photos • Exposure times: • Kodak E200 film, pushed 2 stops • 30 sec (below) • 120 sec (right) • 150 sec (bottom right) • Light pollution sucks!

  13. Mounting the Camera on a Telescope • Duct Tape (Joke!) • Piggyback adapter • T-Ring / T-mount • Eyepiece Projection adapter

  14. Telescope • Clock drive • Polar alignment (guiding) • Focal ratio (ISO speed, etc) • Magnification and atmospheric conditions (seeing)

  15. Vibration, Polar Misalignment • Polar misalignment, wind, vibrations, even footsteps can ruin your images • Take lots of pictures!

  16. Prime Focus Moon Shots • Eclipse (top right) • Varying exposures (bottom) • Enlargement of brightest of the three (bottom right)

  17. Prime Focus M42 • 8” SCT at f/10 • Kodak E200 film pushed 2 stops (800 ISO equiv) • Exposure time: 40 seconds

  18. Summary • You can do a lot with just a camera and a tripod • There are many great web sites and books on the astrophotography • Michael Covington’s book, “Astrophotography for the Amateur” is a great starting point

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