Webcam Moon Mosaic with Xbox Live Vision

A couple of weeks ago I took a series of photographs of the moon using my telescope and the Xbox Live Vision webcam to turn into a mosaic. It took me a while to composite them together, but I managed to do this using some free open source software called Hugin.

Moon Mosaic, 4 Feburary 2011

WebCam capture with Python on Mac OS X

I typically program in Python, and in the absence of any open source astrophotography software for webcam image capture that will run under the current Mac OS X, perhaps I can write something myself. So - how can you capture web camera photos from Python? One way is using OpenCV (originally Intel’s Open Source Computer Vision library). Another popular library is VideoCapture, but it is Windows only.

UVC webcam exposure under Mac OS X

Apple's Mac OS X includes drivers for USB Video Device Class (UVC) cameras, which means that most webcams, including  the Xbox Live Vision, are just plug and play without needing to install any specialist drivers. However, the Apple provided webcam software Photo Booth doesn't allow any control over things like the exposure, gain, or frames per second (FPS), which are quite important in astrophotography. And it only captured at 640 × 426 pixels. So what can we do about this?

Xbox 360 WebCam IR filter

My first blog post was about mounting the Xbox Live Vision camera on a telescope for astrophotography. Last night I removed the built in red glass filter, which makes the webcam much more light sensitive - especially for infra-red (IR). I actually bought a second Xbox 360 camera for this experiment, so I can show photos with and without this modification.

Mains power for multi-speed EQ2 motor

Thus far I've been using my telescope just outside the house, or sometimes indoors when it has been very windy. This means rather than wasting batteries to drive the multi-speed EQ2 motor (and batteries don't tend to last very well in cold weather either), I thought I should look into a mains adapter.