Moving the mirror on the SkyWatcher 130M

My SkyWatcher 130M telescope needs a little help to reach prime focus with a DSLR camera (see also this great blog post). So I decided to move the primary mirror up the tube to allow my Canon EOS to reach focus when attached directly to the T-ring for prime focus astrophotography. This involved almost completely dis-assemblying it, playing with new nuts and bolts, then putting it back together.

I started by removing the spider and secondary mirror assembly, which are held by four recessed screws and nuts on the inside (which should not be dropped onto the primary mirror):

Four screws hold the SkyWatcher 130M spider

SkyWatcher 130M (SK1309EQ2) secondary mirror

PS3 Eye Camera for astrophotography

I was inspired to try out the PlayStation 3 Eye camera for astrophotogaphy after seeing this amazing Orion M42 nebula image taken using a PS3 webcam on a SkyWatcher 130P (an hours worth of 4s exposures and a lot of post processing). Here's another nice thread on using the PlayStation 3 Eye camera with a telescope. It's reported to use an OV7725 60fps 6um pixel VGA sensor and image processor from Omnivision.

PS3 Eye webcam with standard lens removed and replaced
with 1.25" telescope nose piece, with threaded IR filter

Actual test images pending - I need a clear night without other commitments.

Trapezium (Orion Nebula) using Xbox Webcam

I first tried imaging the Orion Nebula (M42) with the Xbox webcam on my SkyWatcher 130M telescope last year, and managed to resolve the Trapezium star cluster. Sadly I can't find the original images, so I tried again last night.

No editing other than cropping

Annotated by hand

As you can hopefully see, there are at least five stars here. Top right as show is the Trapezium cluster (Theta1 Orionis, or θ1 Ori for short), of which only the three brightest stars showed up. Centrally is Theta2 Orionis (or θ2 Ori), and another bright star to the left of it. That means I've captured the brightest stars in the centre of M42 nebula, but in the single stills at least there is no hint of the nebula background.

SkyWatcher Explorer 130M with Canon EOS (Take 2)

I borrowed a Canon EOS 1000D for the weekend, and was lucky to get some clear sky both on Friday and again tonight (Sunday). On Friday I was mostly working out focus travel issues, what modifications might be needed, and how to get any heavenly bodies in focus. Tonight I tried a planet, the moon, and some stars.

SkyWatcher Explorer 130M with Canon EOS DSLR

This weekend I borrowed a Canon EOS 1000D to try out for prime-focus astrophotography when connected directly to my SkyWatcher Explorer 130M (SK1309EQ2) telescope using a T-ring adapter.

Moon using Canon EOS 1000D, held at prime-focus with
SkyWatcher Explorer 130M telescope (SK1309EQ2).
Single exposure, no cropping, no editing.

As well as doing a lot of reading on assorted astronomy forums, I found this excellent blog post about using a (digital) SLR with the SkyWatcher Explorer 130M telescope very helpful, and this page on taking the SkyWatcher focuser apart was informative: The challenge is getting enough inwards focus travel.

Tasco 1603EF focus motor on SkyWatcher SK1309EQ2 telescope

Since I was having trouble with astrophotography focussing my telescope via the webcam, I decided to try out a motorised focus control - sometimes misleading called an automatic focuser. I found the Tasco 1603EF for about £20 all in on eBay, which seemed worth a try with my SkyWatcher Explorer 130M, also known as the SK1309EQ2. I was expecting a little tinkering might be needed but fitting it was extremely straightforward. SkyWatcher do sell their own focus motor at about £50, but it was unclear if this would fit my telescope.

Tasco 1603EF focus motor on SkyWatcher SK1309EQ2 telescope

Tasco 160EF manual focus clutch button

Webcam telescope image of Jupiter & Moons

It is winter again, and the upside to it getting dark before 5pm is many more chances for astronomy. This week I had my SkyWatcher telescope out again, and captured a few images of Jupiter and its moons using the XBox Live Vision webcam.

Wednesday 28 November 2012, Jupiter and four moons.
640 × 480 pixel uncropped image from Xbox 360 webcam,
No filters, prime focus, SkyWatcher SK1309EQ2 telescope.
Single snapshot using wxAstroCapture under Linux.

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

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.

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.

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.

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.