Cademuir » Astronomy

Hacking a webcam for long exposure astrophotography

albertw — Fri, 30 Dec 2011 19:56:41 +0000

I finally got around to hacking a Philips SPC 900 to enable it to take long exposure images suitable for astrophotography. The modifications are fairly well known. The approach I took is a mixture of the http://www.boltonastro.org.uk/Members%5FArea/Projects/spc880conversion.pdf and http://www.yesyes.info/index.php/diy/philips-spc900-webcam-lx-and-ampoff-mod/ .

The circuit between both approaches is roughly the same, I followed the circuit in the former. The modification allows the camera to be switched to a long exposure mode via a switch. The switch can be triggered over a serial port, so I added a USB to serial adaptor and a USB hub (both from ebay) to the unit to allow control from a computer and have just one cable coming from the unit.

As soon as you have some new astronomy kit to try out it inevitably becomes overcast, so no test images just yet however I’ve included some images of the construction.

First Solar Haplha image in years

albertw — Sun, 27 Nov 2011 12:27:35 +0000

I got the PST out again recently. As we approach Solar Maximum it would be a shame not to have a look every now and then.

This was taken by attaching my Canon 400D to the scope. 1s exposure. Green channel extracted, a few tweaks, then coloured orange. The diagonal lines are from Nebulosity, which is image aquisition software that I’m trying out. The free to try version puts diagonal lines in the images.

It needs better focusing, and the red channel with the flares needs to be merged in, but I’m happy with it given its the first image of the Sun I’ve tried with this setup since 2006.

Philips SPC900 Mods

albertw — Fri, 25 Nov 2011 22:50:31 +0000

A collection of some of the main pages describing the long exposure and amp mods for the SPC900 webcam.

Now just to read through them all, order the bits I need, and do the mod. Simples.

Skymax 102mm Maksutov Telescope for Sale

albertw — Mon, 14 Nov 2011 23:37:20 +0000

Hi,

Final bit of telescope equipment for sale for the moment.

This time a compact 102mm Maksutov. I bought this to take abroad for the transit of Venus in 2004 and the solar eclipse in 2006. It’s the biggest telescope that I can take as carry-on luggage on a plane and has a decent enough aperture to still be useful.

Diameter of Primary Mirror: 102mm
Telescope Focal Length: 1300mm (f/12.74)

It came with a tripod adapter but this wasn’t really up to the task and is no longer on it, it does come with 2 O rings and a plate for mounting to an telescope mount (not included!). I’ve been using it on my LXD55 mount (also for sale by the way ) for years.

It also comes with a solid glass 102mm white light solar filter, as well as the carry bag, red dot finder, diagonal, and 25mm eyepiece.

Some solar eclipse photos taken through this scope: http://www.flickr.com/photos/albertw/sets/72057594096922769/with/122029134/

€200. Email me at albert.white@gmail.com if interested. I’m based in South Country Dublin.

LXD 55 Mount for Sale

albertw — Sun, 13 Nov 2011 18:48:34 +0000

I’m selling my trusty LXD55 mount as well as the Telescope (see previous post).

This mount is designed to support the weight of the SN10″ telescope (~15kg). The mount itself with counterweights weighs about 25kg. (See the manual for details on the mount LXD55_Instruction_Manual_revD-1)

The mount comes with the Meade Autostar goto system, and has a built in polar scope.

I’ve replaced some of the screws and bolts in the past with stronger ones than came with it.

Not in photo but comes with the 3 counterweights & shaft, 12v car adapter, D cell battery pack.

€500 – drop an email to albert.white@gmail.com if you are interested. Based in South County Dublin.

Telecope for Sale!

albertw — Mon, 07 Nov 2011 21:43:12 +0000

I’m selling my Meade LXD55 OTA in a Dob mount plus some accessories. The price is €500.

For that you get:

The LXD55 10″SN Telescope (OTA Only in a homemade Dobsonian mount, but includes the O rings)
2 eyepieces, 26mm & 12.4mm Meade Super Plossils.
JMI Motofocus. (cost $169)
Red dot finder.
EZ Collimator (useful for a quick collimation check)
Original OTA box if you want it

I’m selling it with the Dobsonian mount I made for it. This has been my main scope for the last 10 years or so.

The scope is a Schmidt Newtonian design, 1016mm focal length, 254mm diameter (f/4), UHTC coatings.

The mount is constructed from marine grade plywood. I may have overdone the mount and you could probably safely cut some of the weight out of it. The design uses the original ‘O’ rings to keep the scope in place (see image below). This also means that you can still easily use the scope on an strong equatorial mount if you choose.

There is a very minor flaw in the mirror where it was damaged the one time it was ever cleaned. As you can see from the photo (half way down, near the left hand side of the mirror photo) it’s tiny and causes no image quality issues.

The scope does come with a finderscope. However one of the crosshairs is broken! I replaced it with the red dot finder which I find much more useful. It is a wide field scope, so once you have the dot on what you want to look at the object will be easily visible in the 26mm eyepiece.

I bought the scope for IR£1400 back in 2000. It did come with a computerised mount, however the scope was really too large for the mount, a slight breeze causes very frustrating vibrations. So I instead made the Dob mount, and while it does loose the computerised tracking ability it is a much better viewing experience.

I’m selling for €500. It’s located in South county Dublin. You will need a car to collect it. If you are interested you can contact me by email at albert.white@gmail.com

Reason for selling? Well I now have a Celestron 9.25 and since I bought this 11 years ago I’ve got married and live in a small terraced house and my mother would rather I didn’t store 4 telescopes in her house so it’s time to start getting rid of them!

Here are some pics of the scope and a webcam capture of the moon and Jupiter through the scope recently.

Light Pollution Sensor Data for December 2010

albertw — Tue, 04 Jan 2011 01:57:38 +0000

As part of the 2009 International Year of Astronomy our Colleagues at the Kuffner Sternwarte Observatory in Vienna produced a light meter that could be used to monitor light pollution. More details on the project and the meter are available at lightmeter.astronomy2009.at (use login Guest and IYA2009).

There are three stations in Ireland. One in Monasterevin (I’m not sure if it is active), one on the roof of the physics building in Trinity College Dublin, and the one I maintain in South Dublin.

Station Location:
long: -6.11
lat: 53.27
height: 95m
Raw Data: cademuir.data.12.2010

Partial Light Pollution Sensor Data for November 2010

albertw — Tue, 04 Jan 2011 01:55:58 +0000

There are three stations in Ireland. One in Monasterevin (I’m not sure if it is active), one on the roof of the physics building in Trinity College Dublin, and the one I maintain in South Dublin.

Station Location:
long: -6.11
lat: 53.27
height: 95m
Raw Data: cademuir.data.11.2010

Partial Light Pollution Sensor Data for October 2010

albertw — Tue, 04 Jan 2011 01:54:44 +0000

There are three stations in Ireland. One in Monasterevin (I’m not sure if it is active), one on the roof of the physics building in Trinity College Dublin, and the one I maintain in South Dublin.

Station Location:
long: -6.11
lat: 53.27
height: 95m
Raw Data: cademuir.data.10.2010

Partial Light Pollution Sensor Data for September 2010

albertw — Tue, 04 Jan 2011 01:52:12 +0000

There are three stations in Ireland. One in Monasterevin (I’m not sure if it is active), one on the roof of the physics building in Trinity College Dublin, and the one I maintain in South Dublin.

Station Location:
long: -6.11
lat: 53.27
height: 95m
Raw Data: cademuir.data.09.2010