Saturn on a Dobsonian

Saturn is definitely a favourite planet among stargazers. It was always my favourite planet as a kid, even having never seen it in the sky. There was just something damned cool about having rings around it, being different from all the other planets in our solar system.

Using BackyardEOS to capture images through the Dob'

One thing that fascinates me, and always surprises people when I tell them, is what the rings are made up of. The rings are formed of blocks of ice, varying from the size of a pea to the size of a house. Which is another surprising fact, that the rings are only about 30ft thick, so not very thick at all.

The images below were taken using my Skywatcher 8" Dobsonian telescope, with the body of my Canon 600D mounted onto it using a T-ring. As this telescope is stationary, requiring manual movement to find your target, Saturn passes through the view of the camera in around 20 seconds. In order to capture the images below, I used a piece of software called BackyardEOS (which Cheryl bought me for my birthday :-)), which has a feature that records short videos of your target passing by due to the rotation of the earth.

Saturn - using Canon 600D body mounted with a T-ring onto an 8'' Dobsonian 

Each video was around 200 - 300 frames, and each of the frames are then stacked using Registax 6 into a finished image. Stacking basically takes the 'best bits' of each frame, and puts them together. As the light from Saturn takes so long to reach us, it is often distorted.

To increase magnification, a 2x barlow lens was used between the camera body and the telescope, which magnifies Saturn by 2x. This can increase the image size of the end result, but by magnifying it twice, you are halving the time it takes for Saturn to pass your view - meaning shorter videos and less frames to stack together. I am very happy with both results and especially proud that I even managed to capture the Cassini Division - the black line that runs through the middle of the rings. This 'division' is caused by the gravitational pull from one of Saturn's moons (Mimas) causing the debris in the ring to veer off course, causing an emptier section of the rings.

Saturn - Taken with Canon 600D with 2x barlow adapter on a 8" Dobsonian

Each of the images have their good and bad points. I think the first image has better colouring, and is a sharper image as it's not as zoomed in, but the second image has a little more details, but is slightly distorted through less frames and more zoom. A lot of the skill and patience in astrophotography is required in the processing stages. Once you have captured your photos and data, it is using that information the best you can in order to find the best results. It can take hours to stack many images, which may not always achieve desired results. I'd like to one day give more information and tutorials about processing, but at the moment I'm pretty new to it and don't really know what I'm doing most of the time! 

Report: Hunting the Milky Way

Having never actually captured the Milky Way (that big ol' galaxy of ours) I went on an adventure last week and took advantage of a relatively clear evening. I drove over to the Isle of Sheppey, in order to find as darker skies as I could within a reasonable distance. A 25 minute drive saw me in the middle of a number of fields, surrounded by a country path, some noisy birds and, well, that was about it. See the red dot on the map!

I'm going to travel to a few places around my area to find dark skies, and to find appropriate places I could set up my new tracking mount, without getting too much unwanted attention.

I took my camera and tripod out, and once parked up positioned the tripod just outside my car window -using a wired remote I was able to snap shots of the night sky without leaving my seat.

As it got darker, and my eyes adjusted, the milky way became more and more visible to the naked eye as a misty streak of stars drifting from one horizon to the other. I took a few hundred photos, but only happy with a few - it seems the milky way is a pretty tough target regardless of its size. Balancing the exposure to capture the feint stars, without filling the shot with light pollution was also a challenge.

The below shot was my favourite from the night, with the Milky Way clearly visible rising up above the horizon. The majority of the light pollution came from over the water in Whitstable. I may in future try move further West to reduce the light pollution, but like with many aspects of astrophotography - trial and error seems to be the way forward.

An adventure into space

My first lunar capture (September 2008)
1/200, f3.5, ISO 64, 303mm

I'm not quite sure how to begin, it feels as though I should be all excited and enthusiastic about this new journey into the realms of astrophotography.

But in truth, I've been doing astrophotography longer than I have been into photography. The photo on the right was taken on the 13th September 2008. Back before I knew what DSLR's were, before I was regularly uploading photos to Flickr, and before I had any idea how seriously I'd get into the hobby. I had a Fujifilm Finepix S5700, a simple inexpensive point-and-shoot which had a 10x optical zoom. Having figured out what manual was, I captured this shot at 10x zoom on a tripod outside my window. I remember it being a big accomplishment, as I didn't think such photos were possible without huge telescopes or big fancy lenses. I think with a bit of time and effort (same with a lot of things) you are able to push the boundaries laid out by your equipment.

Since then, I've managed to advance a little further into astrophotography, having captured photos of Saturn, Jupiter and more recently the Sun. As astrophotography is a huge hobby to get into, requiring a lot of patience (and money), I'm using this website as a way to monitor my progress and share my favorite photos, whilst sharing what I have learnt to help others going through the same process.

I've invested in a Celestron CG-5 GoTo tracking mount, which (once aligned after a few frustrating hours!) allows you to take long exposures of the night sky, by cancelling out the earths orbit effecting the movement on the stars. This is one of the first steps into capturing deep-sky objects (DSO's) which require longer exposures due to being so feint and not visible to the naked eye. A photo of the CG5 will be in the Equipment page linked here.