Piggy-Back Tracked Wide-Angle Sagittarius and Scorpius This wide-angle astrophoto was taken with the camera and lens riding piggyback on top of a telescope. The scope was on a polar-aligned equatorial mount that was tracking the stars to compensate for the Earth's rotation.

The central portion of the Milky Way, in the direction of the center of our own galaxy, is visible here in the Sagittarius region at left center. The constellation of Scorpius is at the lower right side of the frame. Numerous dark nebula, clouds of non-luminous dust that obscure the stars behind them, are also part of the Milky Way and are scattered throughout the image.

The Milky Way is a vast collection of more than 200 billion stars, planets, nebulas, clusters, dust and gas. Our own Sun and solar system are also part of the Milky Way galaxy.

Seen as a luminous band of light and star clouds that stretch across the night sky, the brighter star clouds of the Milky Way are frequently mistaken for real Earth-bound clouds by observers at true dark-sky sites who are unfamiliar with their appearance. Sometimes interrupted by dark nebulas and rifts, these star clouds are actually innumerable unresolved faint stars.

This image was taken with a wide-angle lens riding piggy-back on top of an equatorially-mounted telescope. It is a single 60-second exposure at ISO 1600 at f/4 with a fog filter. The lens was manually focused with Live View at 10x magnification on Antares, the brightest star in Scorpius. A fog filter was used over the lens to accentuate the brightest stars in the image. A custom white balance was set on the sky background and a bit of blue was dialed in with the camera's custom white balance fine tuning in the menu. The contrast was also increased in the camera and sharpening turned down.

This image is from a single JPEG exposure straight out of the camera. No additional processing was applied. The image was resampled from its original full resolution to fit on this page.

Image Data

• Lens / Scope: Canon 18-55mm f/3.5-5.6 EF-S Zoom IS lens
• Focal Length: 23mm
• F/stop: f/4
• Exposure: Single 60-second exposure
• Mount: Orion Sirius polar-aligned German-equatorial mount
• Guiding: None
• Camera: Unmodified Canon EOS 1000D (Digital Rebel XS)
• Mode: JPEG
• ISO: 1600
• White Balance: Custom, set on sky background
• In-Camera Noise Reduction: None
• Filter: Tiffen Double Fog 3
• Temp: 65F
• Start Time: 4:41 a.m.
• Date: April 28, 2009
• Location: Steelmantown, NJ
• Calibration: None
• Processing: Standard in-camera JPEG processing. Contrast increased, sharpening decreased, color balance adjusted, all in-camera.