Capturing the UK Partial Eclipse with the Canon SX20

On the 20th of March the UK experienced a partial eclipse of the sun. From where I was in the UK it was about 85-90% partial and because the weather forecast offered a good chance to observe it, I decided to have some equipment ready to capture some images.

Because I wasn’t sure what would happen to my camera, I decided to use my Canon SX20 instead of my SX50 in case there was a risk of damaging the cameras CCD. I also had some grade 10 welders glass borrowed from my dad which I intended to fix in front of my camera to reduce the glare from the sun. 

  

The best way I found was to tape the glass to the rear of my Skywatcher 130 telescope and mount the camera on top using the camera adapter on the telescope mounting rings. It’s a bit Heath-Robinson but the cardboard and tape fixing worked well on the day!

On the morning of the eclipse, which was due to start at 8.30am UK time, there was low cloud and mist but the weather report promised that this would clear in time for the start of the eclipse. I set up early, picking a spot where the rising sun should clear the trees at the front of my garden. I had to set the camera up in such a way that it would see through the welders glass as, at a certain distance it would only see it’s own lens reflection. 

  

I also read in Sky at Night magazine some suggested settings for photographing the eclipse, such as a shutter speed of 1/500 and an ISO of 100. Using the full zoom of the SX20 (20x optical) I focused in on the sun in time to see the moon just starting to transit the sun. The weather at this stage was cold but the mist and cloud was rapidly clearing and was becoming sunny. 

Over the next few minutes I took some shots but adjusted the shutter speed down to 1/1600 (the lowest on the SX20) as the sun still appeared a bit too bright in the images. I also used the self-timer function set to a custom trigger of 4 seconds as my remote shutter attachment wasn’t supported on the SX20. A good thing about using a camera in this way is that you don’t have to look directly at the sun, I had special eclipse viewing glasses for this purpose – thanks to the Society for Popular Astronomy and Sky at Night magazines for those! 

  

What was also apparent in the images was a sun spot transiting the left-hand side of the suns face which was quite pleased at capturing!

  

Still sunny, the strength in the output of the sun was becoming noticeably weaker though the light wasn’t the same as the setting sun, it was quite strange and it was becoming noticeably colder. I had to pop inside the house and noticed the sun catching a glass ornament in the living room, which produced an interesting effect where the sun reflected also had the moon transiting. This is best illustrated in the images below. 

  

  

  

Because I had to move back up the garden, by about 9.10am the sun became blocked by a small bush and I had to perform some quick trimming of the top branches to stop my view behind spoilt!

At 9.30am, the sun reached its maximum totality, so I’ve combined a number of images into the image below illustrating the progress of the transit.

  

There had been reports of an ‘eclipse wind’ to watch out for and though I didn’t notice any change at the time, the birds had become noticeably quieter as the eclipse progressed to its maximum totality.

At 10.30am it was all over – considering how poor the weather was in the rest of the UK, I was quite lucky to be able to capture the images I have done.

Now I know that the welders glass works fine with the camera, I think I may try the SX50 with a piece when there is a larger number of sun spots to photograph. With the SX50’s better photographic capability (RAW image output, 50x optical zoom) it should help to produce some interesting solar images – something I’d never expected to be able to do with a point-and-shoot camera!

Website Update

Just a quick update as to what is going on, as there hasn’t been a posting to my blog for a (unbelieveably) couple of months. I’m working on a substantial update to my website http://www.digitalwaterfalls.co.uk which will consist of a number of tutorials, based on what I have learnt in astronomy and astrophotography.

Watch this this space for announcements before the end of the year…!

Posted by Wordmobi

Moon and Mars Opposition

The 29th and 30th of January was the closest approach of Mars since 2007 and the ‘largest’ Moon of 2010. Thankfully the skies in the UK were clear (well, where I live at least!) and gave good opportunity for some observing and astrophotography.

Though my first target was Mars, because the telescope was still ‘warm’ from only just being brought out from the house, this created poor ‘seeing’ from the small air turbulences inside the telescope as it cooled down. This created a shimmering blob effect that when coupled with 2 and 5mm lens, ruined the image.

Whilst I waited for the equipment to cool down, I decided on a bigger target that would be affected less by the aclimatisation problems. So I turned to the Moon and grabbed my Canon S2IS digital camera, holding it upto the eyepiece. Because I’d already worked out some test shots with aperture and shutter speed in CHDK, I applied the settings and managed to get the whole of the Moons disc in the eyepiece. One of the shots is pictured below, though I haven’t had chance to correct the rotation of the image so that the Moon looks the right way up. I had my Moon filter attached to the eyepiece and the only post-processing applied was auto-levels in Photoshop.

moon300110.jpg

By this time the scope had cooled down sufficiently to view Mars. Even though I’d fitted various combinations of barlow lens, 5 and 2mm lenses, I couldn’t manage to quite get much surface detail imaged, except two horizontal curved bands, one of which I guess corresponds to the polar cap. There was a hint of red-orange colour around the edges of the sphere, I didn’t bother trying to try imaging it with my hand-held afocal coupling method of taking pictures with the camera, as I felt it it would result in a blurred image.

Instead, I fixed the camera to the mount on the telescope and took a shot of the Moon and Mars (which was directly overhead), displayed below:-

moonmars.jpg

The image has been rotated and cropped due to the angle that the camera was viewing the scene. A small amount of red’ blue, brightness and contrast has been applied to the image.

Final shot for this post is the equipment setup:-

SkywatcherCanon.jpg

Mars is at closest approach to Earth for the whole of this week, before receeding until 2012.

Posted by Wordmobi

Blue Sky Moon

Getting back from a day out early one evening gave me the chance to image the moon that was high in the sky, whilst there was still some colour blue/light left.

Viewing the moon can gve some interesting results in daylight (from what I’ve read!) so I dragged the Skywatcher 130 down to the front of the house and brought the digital camera as well.

As I’d spent some time prviously setting up the polar alignment, adjusting the RA/Dec axis proved extremely easy, in using only one adjustment to keep the moon in view. I’d also sorted out the red dot finder alignment, so I got an immediate view through the 20mm lens.

I took several shots with my camera, again employing the Heath-Robinson method of simply shoving the camera lens at the eye piece and firing off shots, with various adjustments to the exposure control. This is known as the ‘afocal’ method. The best of the images is below, unforunately the ‘seeing’ wasn’t brilliant so I resolved to get a decent view from the lens I hadn’t really tried yet: the 2mm.

This was the first time that the view really came into its own and I was able to image large areas of the surface as it made its transit across the sky. The view through the 2mm lens can be seen at the bottom of this post. It was difficult to get the camera to capture an image, much adjustment using the afocal method was made and after this shot the batteries gave out on the camera and that was the end of the image capture session.

Coming up next: looking at methods to fix the camera to the eyepiece and Christmas shopping for the Astronomy amateur…

Bluemoon.jpg

moonquarter.jpg

Posted by Wordmobi

Capturing the Moon

After weeks of waiting, the conditions were perfect to view a near-full moon, high in the sky and with dark skies, not affected by light pollution.

Out came the telescope, set up at the front of the house. I fitted the 20mm lens and aimed roughly for the moon. However, frustration set in as despite the moon being in clear view, I could not get it in view, in the viewfinder. After 10 minutes of panning the scope around the sky, I eventually found it purely by chance and wow, what a view!

With the disc in full view in the viewfinder, all the craters and maria were revealed in sharp detail. Changing to smaller lenses brought more of the moon into view, along with the aiming problem. I’ve come to realise that I have some problem where the red dot finder is completely out of alignment and I need to re-calibrate it so that I can aim the scope correctly.

The 2mm lens is proving to be of limited use at the moment, because even though the seeing conditions at lower levels of magnification were fine, the 2mm lens revealed a shimmer in the atmosphere, so I changed back to a 5mm lens.

Grabbing the opportunity to try some direct digital imaging, I got my camera (a Canon S2IS) out and gently pressed its lens against the lens on the telescope. After some moving around of the camera against the lens and some alterations to the camera focal length and aperture (either f3.5 1/60 or f3.2 at 1/60), I managed to capture the following shots:-

moon011109a

moon011109b

moon011109c

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The images have had a little post-processing applied to highlight the dark and light areas of the image, but for a first attempt, I’m pretty pleased and take some inspiration from the attempt.

I must really try and get this red dot finder problem sorted out though…

Filtering out the Brightness

As mentioned in my last post, I tried out the lens filters during Saturdays observations that were supplied as part of the accessories kit. There are four; a moon filter, a neutral density filter, an amber filter and a blue coloured filter. I guess these were chosen for the accessories kit because they are probably the most common types you are likely to use.

Lenses.jpg

Because there was no sign of the moon, I didn’t bother with trying out the moon filter. Targeting Jupiter, I fitted the neutral density filter to the bottom of the 5mm lens, using the screw-type attachment. The lens then fitted into the telescope eye-piece as usual as the filter is flush with the lens.

This actually produced reasonable results, where the dark bands of Jupiters atmosphere could be seen with a little more clarity. The other coloured filters were of less use though. The blue filter only seemed to make the edge of Jupiters disc appear with a blue tinge, but not much for the surface features. The amber filter really did nothing at all, simply turning Jupiter and its moons into several traffic-light blobs. I’m sure the blue and amber filters will be useful, I just haven’t found the correct usage yet.

Now that the moon is starting to climb higher in the sky earlier in an evening now, the next main target to try with the ‘scope is the moon.

Posted by Wordmobi

Bright Lights, Big City

Saturday was a clear night to try out the new lenses that were delivered earlier this week from OVL. Probably one of the best nights so far for getting my telescope out, I set it up in the back garden and as Cassiopeia was high in the sky, decided to hunt for my first object; the Andromeda galaxy, M31.

Having studied my Philips ‘Guide to the Northern Skies’, I had arough idea of the patch of sky where it could be found. Deciding to use the smallest magnification lens in my new kit (the 20mm) to help me have a good chance of being able to pan around the sky and chance upon the object.

Surprisingly enought, it didn’t take me that long to happen upon a faint, fuzzy grey blob. Changing down to the 15mm lens and re-centering the ‘scope, then again to the 5mm lens, the problems of light pollution and living near a big city became apparent. The most resolution I could make out was simply a larger version of the fuzzy blob I spied earlier. The 2mm lens was even worse and I changed back to the 5mm. Satisfied this was the best view I was going to get, I turned the scope around to target Jupiter, which was just coming into view from behind the trees.

This is where is started to get a few problems. I noticed that even though I had a clear aim and lined up the red dot scope direct on Jupiter, the view through through the lens was of the trees a short distance away. Having spent about 15 minutes moving the scope, fiddling with the red dot finder and getting a little exasperated not getting Jupiter in view, I decided that I must have moved one of the adjustment dials on the red dot finder so I simply started to move the RA/Dec dials until I came across Jupiter by chance. Sure enough it came into view and I started to change the lenses so I could get a better view of Jupiter and the Galilean moons.

Changing to the 2mm lens, I came across something that I’d read about in the Astronomy books; ‘poor seeing’, ie. poor focusing due to atmospheric effects. No matter how much I tried to focus, the image of Jupiter continued to ‘wobble’ and be indistinct.

This is caused by heat/turbulence in the atmosphere and makes focussing on the object downright impossible. There isn’t a lot you can do about it so I changed back to a 5mm lens to get back a sharper view.

I did get to try out the filters before I packed up, but I’ll save my findings for my next post.

Posted by Wordmobi