Tuesday, 18 December 2007

S194: Redirect

Having got a bit sucked into this astronomy lark, I thought I better split of the astro stuff rather than mess up my OU story. So there is a spin off blog here.

Friday, 7 December 2007

S194: More astronomy practicals

After my last experiences with Astronomy and telescopes, I decided that photographing things might be more fun. At least I could show the results rather than just describe them.

Now I'd tried before (March 2007) taking some pictures with a telescope and digital camera of a lunar eclipse. This was a very Heath Robinson setup. The telescope is a very basic reflector that I'd borrowed. The camera was a standard point and shoot digital, hand held up to the eyepiece of the telescope. I was actually very pleased with the results given it was a spur of the moment thing. I worked pretty well until the eclipsing happened too much, then the light levels fell, and I couldn't hold the camera still enough to take anything reasonable without a lot of camera shake and the camera waving a red handed blurring gonna happen sort of icon at me.

So - given the very basic nature of the setup it looked like things were possible.

Having got the telescope out again now the nights are getting darker and more accessible, I thought I'd have another go. Bad news, the moon is not visible from my garden, and waning fast. However there are some other things to take photos of. Mars is very prominent right now, and I had a go at taking a photo of that.

No chance, wobblesville Arizona, population you... Pressing the shutter button it was a good 2-3 seconds before the click finished, and there was just a blurred mess.

Well OK, it was probably a silly idea, I should wait for the moon again perhaps.

However flicking through some astronomy web sites and shops, wondering idly how much it would be to buy a 'scope of my own, and what do you get for your money I spotted some interesting bits on astrophotography.

For not very much money (well £20 or so) you can get a metal gizmo that sits on the eyepiece and has a couple of metal bits sticking out that allow you to screw the cameras tripod adaptor into, and suddenly the telescope and camera move as one! See the attached - if I had two cameras you could even see the camera in situ.

This was much easier to work with. You can even use the LCD display instead of the view finder. The only issue is that in the dark, without the camera attached, you stand a fairly reasonable chance of poking your eye out with the protruding metal spike - but hey, its a small price to pay.

A clear night arrived, and I had a play around. The results were not altogether as good as I had hoped, but at least there were results.

MarsMars again
Somewhere in Orion,
or maybe the Pleiades
Another Mars

Well - the results are not stellar (groan) but they are at least there.

Then I had the good fortune to notice that the Nottingham Astronomy Society were having a talk by a visiting speaker titled "Digital Astrophotography for Dummies" by Kevin Kilburn. I could perhaps pick up a few tips, perhaps join the society, get to use their 24inch reflector. At the very least I could find out if I was on the right lines. So off to check it out, on a cold, very wet night to see if Kevin has any tips I might use.


He was getting some stunning photographs without any telescope at all, but using a digital SLR camera on a equitorial mount. The secret was to use a digital camera and take multiple exposure, and then use photoshop or similar to remove the street light pollution, and stack the multiple images on top of each other.

The results are excellent. I was well and truly inspired as I left the meeting. He was getting pictures better than a lot of professionals, and using them to propose new theories about the moon and other things. I mean - just look at this example of M31, the Andromeda galaxy, our nearest neighbouring galaxy. Many of these were taken from his own back garden, from which he can see 12 street lights.

This could end up as a relatively expensive night out in the long run...

Tuesday, 4 December 2007

A251: Counting down to the ECA

Its the 4th and last part of the course. It depends now why you are doing the course. If you've got a burning interest in the material then there is lots to read. If on the other hand you're doing it for the points, or you're suffering Human Past fatigue, or you just want to be free over Christmas - then the ECA is the goal to be aimed at. As such, it is not really clear how much of the chapters left to be read have any use for the ECA questions.

The questions, to which you need to write 2,500 words worth of answers to one of are:
  1. How has demographic increase affected the development of human societies?
  2. In the archaeological record, what has happened when cultures have met?

So its not immediately obvious why reading several pages and online articles discussing rock art will help you much with either of these.

I think I'm going to pick the 2nd of the two, as TMA-3 has already given a few examples to consider. The Human Past, for all its size, is quite light in details on some of the civilisations that might be considered. It has very little on the Persians, and not a great deal more on the Inca.