Showing posts with label beginner. Show all posts
Showing posts with label beginner. Show all posts

Friday, 26 July 2013

Report: The hunt for Messier Objects

I went to the pub with a few friends from the local photographic society, and eventually got home about 23:30. I looked up, as I always do, and saw it was a good clear night (you know - when you just seem to see more stars than usual). So decided to quickly cart my gear into the garden and set up. 

Galaxies M81 and M82
Click for annotated version
By around midnight I was set up and aligned - I'm starting to love the routine of setting up now - tripod facing N? check, tripod level? check, Polaris aligned? check, north star focused at 10x zoom with DSLR? check. Once I was star aligned I popped back into the house to look at my report of what there is to see that night, wrote down in my notebook M39 - an open cluster in Cygnus. Having looked at a few images of it, I saw it wasn't your usual cluster (no cloudy blob of stars) so I noted down a rough sketch of what I should be looking for.


So I head downstairs and outside, and punch in M39 on the keypad and watch it slew to the right position. I look up to see... cloud. Bright lit-up-by-the-goddamn-moon type of cloud, moving in. I quickly fired the shutter for 30s to see if I could at least catch something before the cloud came in, but looking at the image after - a hazy blank image with the most prominent stars just shining through.

So I headed in and shouted at my girlfriend about how annoying it all was and she said to just wait a bit, it may pass. But of course, I'm sure you all know, there's never an opening in the cloud! I then noticed there was a clear area of sky lower down toward the horizon, so quickly found some more targets to try out. Armed with my list - M51, M52, M81, M101, I had another go.

M52 - Open Cluster in Cassiopeia
Click for annotated version
First, the pinwheel and whirlpool galaxies - I managed to capture them, but laughed at how feint they were and decided to leave them for another night. Then I moved onto M81 & M82 and got a surprise, they were surprisingly clear - however, due to the theme of the night, it wasnt perfect. The neighbours tree decided to stick a branch right through my field of view. A few more swear words and I then slewed over to M52 - Open cluster in Cassiopia - it was there my luck changed. It looked stunning, a clear hazy cloud of stars on a black background was what met me on my camera screen. I spent about 10 minutes then capturing exposures to stack. I then moved back to M81 & M82, to see if they'd moved clear of the branch - to which they had :-) Good times! - another 10 or so minutes worth of exposures on these and I then realised the clouds had passed, revealing M39 - my original target. A quick final slew and there it was, clear as anything. I took a few shots, then compared the formation of the stars to my sketch - even showed my girlfriend who was very impressed how I found such a formation in the sky that was exactly the same to what I had planned/drawn out. Another 10 minutes or so of exposures and I decided to call it a night.

M39 - Open cluster in Cygnus
Click for annotated version

The only thing I am a little disappointed with, is I completely forgot to get some dark frames. Though my last few sessions have mainly used the same camera settings so could possibly use some of those.

I finished viewing at around 01:00. Came inside, then wrote down the file numbers of each object from - to, as I find this is much easier when I come to stacking as I know which RAW files to stack - considering I can't preview the image quickly.

The following day I processed the images using Deepskystacker 3.3.3 (beta version) and then touched up the images in Photoshop CS5. I'm really happy with how they came out, especially the two galaxies.

Thursday, 11 July 2013

Report: First light with Evostar 80ED

New Telescope - Evostar ED80 on CG-5I returned home from work yesterday just to meet the delivery driver at the door, to receive my new Skywatcher 80ED telescope. Unboxing it I felt like a child at Christmas, slowly taking pieces out of their protective bags and looking at them wondering what each bit did and what goes where. I first mounted the scope on my CG-5 and just played around with the balances, counterweight, and just getting a feel for it. There it stayed until it got dark (my girlfriend wasn't too impressed with it being left in front of the TV and her being too afraid to move it knowing I've spent an entire months salary on it all).

Then a miracle happened, I had clear skies. They weren't perfect as here in the UK has been very hot and muggy, so there is a slight haze lingering around in the evenings, and I went out pretty early - Polaris was quite faint as it wasn't long after full sunset, but I was eager to get out there and playing. Having lined up the mount with Polaris, I had a look through the camera's viewfinder (camera attached with a t-ring to the back of the scope) and was greatly surprised to find Polaris in sight, not right in the middle, but it was there. I then aligned the mount with Arcturus, Dubnhe and Deneb? (I think!) and took this opportunity to line up the finder scope, which always surprises me by how much you can see through them.

First target was the globular cluster in Hercules (M13). I took a few exposures, and initially noticed I was slightly out of focus. To fix this I navigated to the nearest bright star using the GoTo and used the 10x digital zoom to make tuning much more accurate. The fine-tuning focuser really helped too. Back to Hercules and things were much clearer, though in fairness it did seem to come out similarly to when I was capturing it with my 300mm lens.

I tried out a few other targets, the pinwheel galaxy was unsuccessful, and I couldn't even make out the feint shape of it like I could with my 300mm. The Dumbbell nebulawas visible, but a little faint, and again similar result to the 300mm lens. So I decided not to get too disheartened and went back to the Hercules cluster. I took roughly 4 minutes worth of 30s exposures, and ended up with the following result:

Hercules Cluster M13 through Skywatcher Evostar ED80


I'm happy with the result, but it's a little darker than I'd have liked but I didn't want to burn out the centre as I have with my previous attempts.

Here is the same target with the 300mm lens and around 15 minutes of exposure, I took this a week or so ago:

Hercules Globular Cluster - M13

When comparing the two, I think the ED80 clearly shows more details and especially from a shorter total exposure. I now just have to find a way to prevent the middle from becoming burnt out and over exposed.

I have to admit, my first impressions of the scope are good, but there is a little doubt. The results from this first session were very similar to what I was getting with the 300mm lens. I know full well that this telescope is a good tube, and I know i'll be able to get some great photos with it, but at the moment I don't think I'm seeing that just yet. There is clearly much more room to work on and more to learn, and hopefully I'll be able to see real improvements compared to images with the 300mm lens (otherwise I'll feel like I've wasted a bit of money!).

Monday, 24 June 2013

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
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 this evening
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! 

Thursday, 20 June 2013

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.

The Milky Way

Tuesday, 18 June 2013

An adventure into space

Moon on 13th Sept. 2008
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.