Tuesday, 31 January 2012

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?

Sunday, 29 January 2012

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.

Saturday, 28 January 2012

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.

Inside the EQ2 motor controller

I decided to open the control box for my SkyWatcher telescope's EQ2 mount multi-speed motor. Other than curiosity and to see how you might fine tune the speed, my main goal was to check the 6V power supply polarity in order to connect a mains adapter.

Multi-speed motor for SkyWatcher EQ2 mount

After trying the single speed simple economy EQ2 motor with my SkyWatcher telescope, I decided to upgrade to the multi-speed version which I think is much nicer to use and definitely worth the extra money.

Saturday, 14 January 2012

Simple motor for SkyWatcher EQ2 mount

My SkyWatcher telescope came with their entry level equatorial mount, the EQ2. This is designed to allow the right ascension axis to be motorised, so that it turns to compensate for the Earth's rotation. Without this, you must manually keep tweaking it! With the motor, you can point the telescope at something in the sky and have it "stay put" for longer. This obviously is quite important for astrophotography, but also simply for sharing a good view with anyone else. Here's how I got on with fitting the simple EQ2 motor.

Wednesday, 11 January 2012

Xbox 360 WebCam for Astrophotography

Xbox Live Vision (green LEDs on)
My Christmas present this year was a telescope, and after successfully using it on the first couple of clear evenings to observe Earth's moon, Jupiter and its four biggest moons, I wanted to try and take some photos - without spending hundreds of pounds if I could help it. From some reading online, connecting a web camera seemed to be the best plan.