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View from a Scope | August 24, 2017

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New Telescope Day + 7

New Telescope Day + 7

I am little late in coming back with a review of my initial experiences with my new telescope. I don’t think I actually mentioned in my last post what telescope I got. It is a Skywatcher 150p on an EQ3-2 mount.

What that essentially means is that the telescope was made by skywatcher, has an aperture of 150mm (6″) and uses a parabolic mirror. EQ mounts are equatorial which means when set up correctly they can accurately following objects in the sky along the same angle as earth rotation. The 3-2 is the model of the mount.

 

Anyway I have been using the scope for over a week now and the first couple of nights I had the scope there was lovely clear nights to stargaze, unfortunately the last week has been terrible, so have got no viewing in at all.

Ok on to the first proper night out with the scope, I had spent the entire day lining the scope up and tuning the mirrors (this is called collimating the scope), this is lining the primary and secondary mirror up so you get as clear an image as possible.

Tuning the Telescope

Before I bought the scope I had read a lot about collimating a reflector telescope and a lot of people recommended getting a laser collimator which I did. This device allows you to shine a laser down the telescope tube, have it reflected back of the primary mirror onto the secondary mirror and onto the white target of the device, the idea being that when the laser is in the center of the target the telescope is properly collimated.

Unfortunately I only read half the instructions and was actually making things worse by only moving the primary mirror to line the laser point up with the target. I went out viewing with the scope that night not realising my mistake, and although I could still see objects, focusing on them was hard and my field of view was dramatically reduced. I will admit at one point a sense of dread overcame me and I started wondering if the telescope had being damaged. So I brought all in at examined the scope, it was only when I was looking down the tube did I notice another small target printed on the primary mirror, I set up the collimator again and I could see the reflected point on the primary mirror was way of, to fix this I needed to adjust the secondary first, then adjust the primary once the laser dot had being lined up.

Imaging

The next night I went out the difference in image was amazing, I was starting to see real detail in nebula, and could easily make out Jupiters clouds, unfortunately the Great Red Spot was on the other side of the planet.

After a long time viewing different deep space objects I decided to try and take a photograph of one of them. I had purchased some adaptors (picture left) to allow me to connect a canon 400d DSLR camera to the focuser and essentially use the telescope as a camera lens, (this is called prime focus astrophotography). I also purchased a motor to allow the telescope to counteract the rotation of the earth, allowing an image to stay in the viewfinder. This is essential for long exposure photography, which is what is needed in astrophotography to help tease out the colour and detail from these object 100’s of light years away. As it was getting late I didn’t really spend as much time on setup as you should.

To do it properly you should get a really good polar alignment (lining the mount up with the north star), focus on a bright star and finely adjust the focuser until you have a pinpoint image, I did none of these, I just roughly lined the scope up with the north star, took a view photos of a bright star until it looked ok on the camera screen. I then point the scope at the Orion nebula (located in the sword of Orion).

I took a 1 minute exposure of the area, and when I seen the results I was blown away.

 As you can see from this picture the stars are kidney bean shaped, I believe this is due to the image not being in focus, Also 1 minute might have being pushing it exposure time for the wee motor I had, from what I understand what you should do is take a lot of photos with a lower exposure time and stack them on top of each other. This would build up a lovely picture. Even so I am still delighted to be able to capture this on my first go without any real setup time or effort.

I could not wait for the next clear sky so I could do it the right way, unfortunately I am still waiting, the weather here has being terrible. While I have being waiting though I have stripped a webcam and placed it in a 1’25” tube. This should allow me to video through the telescope. This technique is supposed to be ideal for taken photos of the moon or planets. I will go more into this in another post.

Anyway that’s about it for now. So far I am over the moon (wink wink) with my new telescope, the fears I had before I got it about the scope / mount not being good enough for astrophotography, or the finite detail you needed to setup before taken a photograph has largely being laid to rest. The photos I take wont be anything near the ones you see in books, but you know maybe some day I might stick them on my wall. Which is good enough for me.

On a final note, I find it amazing that this the photo above was taken from a small village in the north of Ireland, with very modest equipment and operator with more luck than knowledge. For some reason I had in my head that photos like this only came from some mountain top in Chile. The point is if you can see the stars from where you are, you can take photos like this as well.

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