Whether for you own enjoyment or group observing, you can break into digital astroimaging with a minimum of time and little or no cost. You may already have everything you need: a telescope with tracking capability, a computer (which you don’t mind taking outside), some free software, and, of course, a webcam. I’ve tried a variety of models, although some are better than others. Nowadays, all come with a USB connection. CMOS chips are less light sensitive than CCD’s, but will work for bright objects. A favorite camera among many hackers, the Philips Vesta Pro Scan (photo 1, at right), sells for about $70 (and is getting hard to find) and has a CCD chip, good low-light sensitivity (<1 lux) and twice the resolution (640 x 480 pixels) of low-end cameras. This camera is often packaged as a portable page scanner and can be easily switched between office and astro uses. Geoff Chester (see web site below) has taken some remarkable images with this webcam.

With a webcam and a plastic, 35-mm film can (2), here are six steps for hacking a webcam:

1. Install camera software and driver as directed and verify that the camera works
2. Install Vega 1.2 or AstroVideo for astro-imaging operation, test it, and practice capturing video and images in a well-lit room
3. Hack the camera by removing lens and filter (3), and adapt it to fit securely in telescope eyepiece using a film can with the bottom cut off (4) and hot glue (5)
4. Try imaging the Moon or bright planets in one or more nighttime sessions--practice here will payoff later--finding objects and focusing can be challenging!
5. Select, composite and process your images with AstroStack, AstroVideo and/or other image processing programs
6. Have fun with your new astro-camera! (6)

Modifications to one such webcam are depicted in steps at right ("mouseover" the image to see a brief description). Do try to keep dust and dirt away from the chip or these will appear as huge boulders on you computer screen! To finish (7), a film-can cap with a wedge cut-out will serve as a dust cover.

I have found these web sites to be very useful sources of instructions, advice, sample images and software: QCUIAG, the QuickCam and Unconventional Imaging Astronomy Group; Geoff Chester’s WebCam Imaging Adventure; Vega image capture program (freeware); AstroStack image enhancement program (freeware); AstroVideo web site (shareware, $30, but worth it); and adapters for Vesta Pro and other cameras.

If you try this, please let me know how it works for you. I'll have more on what to do with your webcam images of the Moon and bright planets in a future installment. Many thanks for advice and suggestions from Tom Pomponio, Bob Stewart, Teri Young and Dave Groski, and many others at the Webcam Hackshop 2002 at the Mallard Lodge. I have personally used these modifications successfully on a number of webcams and computers. But you alone are responsible for what happens to your webcam, computer, files, telescope and images. You should realize that these camera modifications will likely void the warranty, and that installed drivers and programs may not function or may have unintended or unfortunate consequences. Operation of the webcam and computer in the dark, with connecting cables, and under cold or dewy conditions presents additional challenges to the astroimager. This is one reason that I recommend that you practice with the webcam in a comfortable situation. Even inexpensive webcams simply modified are capable of remarkable results, but remember that “your mileage may vary”

Moondark is written by Doug Miller, published on the web, and printed in the Delmarva Star Gazers' Star Gazer News. Please address comments and suggestions to dcmiller@dmv.com. This document was last revised on 24 March 2002. All text and images copyright © 2002 Douglas C. Miller, All Rights Reserved. This material may not be reproduced in any form without prior permission.