Posts tagged “venus

This astro stuff DOES get easier, slightly…

Equatorial mounts, Newtonian reflectors, refractors, registax, counterweights, polar alignment, autostakkert, wavelets, webcams, tracking motors, collimation, Saturn, Venus, avi’s, sharpcap… Astro photography, it’s enough to put you off just thinking about the bewildering array of stuff to learn. What the hell are those things, where are they, what do they do, how do I use them? Well, with a little perseverance it DOES get a bit easier.

Take the telescope and mount to start with. When I first got it I had no idea what I was doing, Even now the EQ5 mount seems more like an instrument of mental torture than something to mount a telescope on but I am getting used to how it works. I’ve never attempted an accurate polar alignment yet mainly due to how late it is in summer until I can see Polaris but even a rough alignment is enough to get you moving. Simply set your latitude on the mount, 55 degrees for Edinburgh point the North leg funnily enough North and make sure the mount is level. It’s not perfect but it’ll allow you a go at some planetary imaging at least.

Just doing the above steps I’ve found that it’s adequate enough to keep a planet in the field of view for ages with the tracking motors engaged. It wouldn’t be any use at all for imaging deep space objects but for now, for planets and moon its working ok.

The tracking motors too came with the vaguest of instructions, now though I’m confident enough to find my target, lock the clutches and start the tracking and it works fine.

So, as I’d got hold of a Philips SPC900 webcam, all ready to be used with the scope and the skies had cleared it was time to give this planetary imaging a shot.

There’s not a lot of targets at this time of year, Venus is rapidly heading for its appointment with the Sun in June and Jupiter is long gone is the twilight sky. Saturn is getting higher and Mars to be honest has never been my favourite subject so Venus and Saturn were to be the targets.

When I setup, only Venus was visible in a still twilight sky. I can’t wait till dark as it’ll be lost behind the neighbourhood roofs. It’s so easy to locate in a twilight sky and the crescent shape is very visible in the scope and it’s quite a thin crescent now too. After centering Venus in the eyepiece I slipped in the 2x Barlow and made sure it was centered and then switched to the webcam.

Luckily for me, Venus was still there with the webcam and using the free capture software, SharpCap I was able to get it centered on the camera and adjust the settings till I got a clear view. I got a couple of short captures with the webcam until Venus was lost to the shed roof. I then ran the avi file through another free bit of software, Autostakkert which stacked the best frames from the movie.

The resulting image was saved as a TIFF and then opened in Registax 6 where you can adjust the wavelets. I have no idea what a wavelet is but it certainly works and greatly brings out the image detail and sharpness. I then finally opened the image in Photoshop CS5 for some final tweaks and this was the end result.
Venus 19 May 2012 Cropped

A million times better than I’ve managed with the DSLR, the webcams much smaller sensor gives a much bigger final image which in turn lets you get more detail. Using a webcam also lets you capture those microseconds of clarity through the atmosphere where the viewing is at its clearest and the stacking software puts all these together to get your final image. It takes a bit of getting your head around but it does work!

Saturn was next up and this was the AVI file I processed to get to the final image:

It’s probably way too long but after processing this in the same way as the Venus image I got to this final shot.

Saturn 19 May 2012

Which is a vast improvement on my best with the D90 attached to the telescope:

Saturn

As you can see, there’s a lot more detail in the stacked image, some colour too.

For a first shot with this style of imaging I’m pretty pleased especially as the seeing was pretty bad. There’s a lot of room for improving especially with the software end all of which I’ve hardly even scratched the surface of yet. I also need to get hold of a quality 5x Barlow lens to get a larger image. Lots to do, I just a few more clear nights!


First time photography with a telescope

After only a mere 3 days of frustration of owning a telescope and not being able to use it for the purpose it was designed, I finally got a clear night to try out a bit of photography with my newest photography acquisition, my Skywatcher Explorer 200P on an EQ5 mount.

With a clear sky looking almost certain the hardest part of waiting till it was dark enough to actually see anything in the night sky on Friday night. The moon was coming up frustratingly low and was steadfastly refusing to peek over the top of the house from my back garden so I was forced to wait until the sun had at least waved goodbye for the day.

While still in a twilight sky I obviously couldn’t properly polar align, not that in a dark sky I’d probably have had any more luck either if I’m honest! I did make an attempt though, first finding north using the iPhone compass, so it was probably east or something knowing the accuracy of the iPhone compass and I did level out the mount properly too. With this being the best I could do in a twilight sky I made an attempt at balancing the telescope and that was me ready to go.

I’d spent time earlier in the day setting up the finder scope so with Venus bright in the sky that where I headed. Centred nicely in the finder scope I looked through the eyepiece to find… nothing at all. After some searching I did find Venus and even in the 20mm eyepiece it was a brilliant sight. The crescent clearly defined and even better, the tracking motors seemed to be keeping it in the field of view as well. So far so good.

With Venus in my sights I setup the MacBook pro and tethered it to my Nikon D90, fitted the t-ring and the 2x Barlow (which is needed to get the prime focus) and switched out the eyepiece for the camera and watched the scope drift off on a tangent with the extra weight fitted. Re-balancing and trying again finally I got Venus in the D90 viewfinder and switched the live view on the laptop. This gave me a chance to play with some settings and get a few shots, none of which I’d be willing to stick up online…

By this time Saturn had peeked over the top of the house so that’s where I headed next. Despite a glaring moon just below it the view wasn’t bad at all. Easy to find, find the roof and move up, Saturn was an awesome sight, the rings and some of the moons clearly defined in the eyepiece. With the tracking more or less working I got a good chance to try out some single frame shots of the ringed planet before youngest son walked into the 5m USB cable between the D90 and MacBook pro knocking everything out of line again.

This was the best I got of Saturn, not exactly epic but I was pleased enough for a first go.

Saturn

Next up was Mars which was… unexciting so I skipped Mars and went in search of the Moon which was still hiding around the front of the house. Moving the scope I got a view of the Moon and within mere milliseconds of getting it in the eyepiece I realised the importance of having a Moon filter. There’s no way you should be looking at a nearly full moon without one. I worried for a bit I had damaged my left eye, the black spot the Moon left in a field of vision a bit of a worry to be frank! Thankfully it subsided and I won’t be doing that again. I did however hook up the camera and use the live view to the laptop to focus and get a few shots, the best of which is below although I’m frustrated at the lack of sharpness in the shot.

Moon 4th May 2012

The list of questions and things to learn is still massive. Among these…

1. How can I get the whole moon in a single photograph with the camera, the 2x Barlow means only bits at a time and when I tried eyepiece projection the result was more like a lensbaby shot with selective focus!

2. How the hell do you find deep space objects without a GOTO? I’m really thinking I’ll need to invest in the SynScan controller soon.

3. The tracking motors SEEM to work but I’m not convinced, Skywatcher seem to be overly vague in their operation.

4. How the f**k do you balance a telescope for the eyepiece and camera without having to adjust where the scope sits on the rings?

5. Where the hell did all these eyepiece caps come from? As the night wore on I seemed to have more than I had places to fit them?

6. Why do I need a woolly hat, scarf and big jacket in May!

7. Why did I buy such a heavy unwieldy telescope in the first place!

These, and not doubt many more questions may or may not be answered in the coming months…


Preparing to photograph the ISS

I have to say, the International Space Station is an engaging photographic subject. Hundreds of miles above the planet traveling at 17500mph it wouldn’t be the first thing you’d think of nipping out with the camera to capture. However, once you figure out roughly where it’s coming from, what you’re looking for and when it’ll be there it’s almost addictive.

If you happen to be on Twitter try following some of these accounts and you’ll be amazed at how many retweets they send out of images after every visible pass over the UK.

@VirtualAstro
@PeoplesAstro
@NewburyAstro

Planning for the ISS makes a huge difference. The @VirtualAstro twitter account is a good place to start, there’s a wealth of info for every pass from that particular source. The website, http://www.heavens-above.com is also good for working out the directions, altitude and brightness of the ISS for any given pass. The free astro programme, Stellarium for Mac or PC is also very helpful, it’ll show you the exact path the ISS will take and from this you can work out in relation to the planets where it’ll be which makes planning a lot easier. The iPhone app StarWalk also allows you to do this.

Here’s a screen dump from Stellarium and from it you can see the ISS path for tonights pass in relation to Sirius and Mars, two of the easier night sky objects to spot.

This is a screen dump from the iPhone Star Walk, from here you can see the ISS and you can advance the time with the bar on the right to watch the path it’ll take over the sky.

Typically the nearer to sunset the longer the ISS will be visible, approx. an hour to 1.5 hours after sunset you’ll get a very bright pass almost from the western horizon to the east later in the night, it’ll disappear into the earth shadow quicker.

So, with this info in mind the temptation is to sit in the house watching the telly and nip out just as it’s about to pass. I’m guilty of it too. But if you apply a little landscape photography principals to the astro info you can totally change the shot you get.

Photographing just the sky is fine, and even better if you can get something significant in the sky to reference the ISS path, i.e. passing Mars, or Saturn. However, get the land in the shot and you’re starting to tell a story with your shot, you’re showing the whole event. The pass of this object over the scene you’re looking at. So tell me whats better here…

The ISS crossing over my back garden, passing just over Saturn

ISS flies over Saturn 14 April 2012
Or this image taken on the Cammo Estate in Edinburgh

ISS over Cammo Edinburgh

The 2nd image took a stack of planning to get. All the info above plus looking at Google maps to find a location with good views to the west, south and east. The only issue I had with this image was the clouds were obscuring Mars so I couldn’t get a reference for how high the ISS would be in the sky, with hindsight I should have used a wider lens but we can all be great in hindsight can’t we?

Using Star Walk I figured out roughly where on the horizon the ISS was going to emerge from and composed the shot to catch it as quickly as I could as it rose, also keeping in mind I wanted Cammo Tower and the copse on top of the hill in the shot. Ground was kept to the bare minimum required and the sky was the main focus.

The sky was still quite light so I went for a balance to catch the ISS. I used ISO320 and f4.5 and limited the exposures to 10s, this gave a nice balance in the shot but meant enough sensitivity to get the light from the ISS.

In the end I got 12 frames of 10s each until the ISS left the field of view, being an early pass I had time to recompose and get another few frames before it disappeared.

The 12 raw images I took into ACR and processed them all exactly the same and saved as jpg files. These 12 jpg’s were loaded into StarStax and blended on lighter mode. This was fine, the ISS trail was night and bright but the cloud movement was nasty and not smooth. To get around this I stacked the 12 images again using the “average” method which gave a much more pleasing image with the clouds but a faint ISS trail. I then blended the first image into this on lighten mode and decreased the exposure until only the bright ISS trail and stars remained. The resulting image was flattened and tweaked in photoshop to produce the final image.

If I were to process again I may patch in the gaps in the trail between the exposures and as a personal preference I would also try to lose the star trails by blending in another image and selectively deleting the trails.

With a location like this though and a nice (nearly clear sky) it’s worth taking time for a few other shots before you back up.

This was a single from from the composite image. Notable objects in the shot are the ISS, Mars, Regulus, Sirius, and Orion.

Mars and ISS over Cammo Tower

In this shot, the ISS can be seen behind the clouds passing just over Saturn and Spica.

Saturn Spica and ISS over Edinburgh

In this final shot taken just after the ISS pass, Venus is nestling on the branches of this particularly creepy tree!

Venus in the spooky tree

A little planning can work wonders, it’s all just about planning and crossing your fingers for the weather to play ball. It won’t work out every night but for that odd one it does you’ll be well pleased you put in the effort.

Get out and look up tonight and for the next few nights before it disappears under the horizon for another few weeks!


Stars, Planets, Snow, Hail and Wind!

One thing about Astro-photography, you’re totally at the mercy of the weather. No matter what’s going on in the night sky, you can only see it if the clouds let you see it. There’s nothing you can do about it other than cross your fingers and hope that as darkness falls the skies clear. Which predictably they don’t 9 times out of 10. The conjunction of Venus and Jupiter last month being a perfect example. The night the 2 planets were at their closest in the sky thick cloud hung about all night over Edinburgh spoiling the celestial display.

With the weather rollercoaster central Scotland was experiencing yesterday I held out little hope of even seeing, let along photographing 2 meetings of night sky objects last night. All afternoon the weather swung from heavy snow/hail showers to broken cloud and back again. As the twilight approached this was still the case so getting anything was going to take timing and a hefty dose of luck.

With this in mind, I set up the camera and tripod in the garden shed. This is the kit I’ve been using until I finally get my telescope. It’s a Nikon D7000, fitted with a Sigma 70-200mm f2.8 EX HSM and 2x tele converter which gives me a 400 f5.6 lens, 600mm on the Nikon crop sensor. The D7000 is fitted with a Hahnel Giga T Pro remote receiver so I can use the powerful IR remote to trigger the camera. Exposure delay mode is on the try and minimise any shake. At 400mm the slightest movement will be obvious, more so when the subject is many thousands of light years away.

The first object to try for was the conjunction of the planet Venus and the Pleiades open star cluster, also known as M45 or the Seven Sisters. Venus has been steadily getting closer this month and on April 3rd it was sat right on the edge of the cluster to our view. 400mm fills the frame nicely and even though M45 wasn’t visible in the twilight sky, the camera could see it. There was just the small issue of the passing torrential hail shower to wait out first. As the dirty ominous clouds passed I got my first few shots at the target which was made difficult with a biting strong wind. 18″ long lens setups and strong winds don’t go too well together.

So, high ISO of 1600 and 1s exposure to try and keep the stars as dots rather than oblongs and the full 400mm was the order of the day. The wind affected a lot of shots but this was the pick of the bunch. Venus is of course very bright and the star cluster much dimmer, so I exposed for the stars and let Venus appear as an attractive starburst. Exposing for Venus would leave the stars not visible at all.

Venus Pleiades M45 3 April 2012

This shot was taken later on in the night with a darker sky and the 2x teleconverter removed to try and combat some of the “wind wobble”. ISO1600, 200mm and f5.6, 0.8s exposure time.

Venus Pleiades M45 April 3 2012 2

The 2nd object of the night was the close proximity of the Moon to Mars and the star Regulus forming a celestial triangle in the constellation of Leo. The clouds hadn’t parted at all over this part of the sky and it took a while to get any hope of photographing it. With the 2x tele removed due to the distance between the objects around 9.45pm the clouds moved and I got my first shot at the Moon. The final shot had to be a blend of 2 shots, one for the Moon and one for the planet and star. To expose for the very bright Moon left Mars and Regulus nearly invisible, to expose for Mars and Regulus burned out the moon totally and worse still caused huge lens flares.

Moon Mars Regulus in Leo

As the clouds rolled over again the final shot of the night was a closer shot of the moon with the clouds looking all atmospheric. ISO800 at 400mm, f5.6 and 1/25th exposure time done the damage. It’s hard to get decent focus with clouds moving over the moon so I consider this a fairly lucky shot.

Cloudy Moon 3 April 2012

An enjoyable, if cold, night but hammers home the need for a telescope again, even just for tracking purposes it would be invaluable. I’ve pretty much decided on a Skywatcher Explorer 150p Newtonian on an EQ3-2 mount which I’ll fit with the optional motor drives. Hopefully I’ll have it soon when the real fun and steep learning curve will start.


An Evening of Astro-Photography

I’m obsessed with the night sky just now. Which is unfortunate as now we’re into BST the night sky is coming at a more unsociable hour. Who’d have thought after a long winter I was going to miss the dark nights? I’ve enjoyed my recent journey into some low level astro-photography, even without a telescope to really start on deep space and planets, with some modest photography equipment it can be an engaging subject to photograph.

A crystal clear sky on any night is a joy to behold, especially if you’re away from heavy light pollution, and it’s even more enjoyable once you get an idea what you’re looking at. Last night (March 26th) was one of those special nights with a conjunction in the night sky, where 2 or more celestial bodies appear close to each other in the night sky. Last night was the turn of a nice thin crescent Moon and Venus to take centre stage.

Unlike the night before when Jupiter and the Moon were in conjunction the sky had finally lost that misty haze of the last few days and the seeing was very good indeed. Without a cloud in the sky it was too good an opportunity to miss.

We’ve all seen the proper astro-photography stuff, those striking coloured images of distant nebula or close in shots of planets which is specialised stuff but with a basic camera setup you can have a great night working these special night sky events into your pictures.

All pictures were taken with a Nikon D7000, on a tripod and fired using a wired remote control, but most cameras would do a decent job with a mid range zoom lens.

This close in shot of the Moon and Venus show’s just how close they were in the sky. This was taken with a Sigma 70-200mm f2.8 and 2x teleconverter, and it filled the D7000’s frame perfectly. 1/60th, f5.6, ISO400 and 400mm. The moon needs a fast exposure to stop the detail burning out as it’s a very bright object, a full moon requires a even faster shutter, luckily Venus is so bright its fine with the faster shutter speed too.

Moon Venus conjunction March 26th 2012

Switching now to a Nikon 18-200mm VRII lens, a general purpose mid-range super zoom, we get a wider view of the same scene. This time though I’ve slightly lengthened the exposure to 1/2s, f5.6, ISO400, -2/3ev and 200mm. The result is lost detail in the bright part of the moon but I’ve picked up the Earthshine instead, the light reflecting back of Earth lighting the shadow portion of the moon.

Moon Venus conjunction with ES 26 March 2012

Pulling back the zoom even further it was possible to include Jupiter in the shot as well. Same settings as the previous shot, but at 135mm. Jupiter is on the lower right of the shot.

Moon Venus Jupiter conjunction March 26 2012

It’s all very well shooting the moon and planets on their own, you could do that from your own garden probably, but sometimes it’s nice to get a little context to the shot as well. I was at Blackford Pond in Edinburgh, not long after sunset when I was taking these so a bit of playing about got the 2 planets and the moon with the tail end of the sunset over the pond. 1/8th, f5.6, ISO400, 18mm, -4/3ev.

Conjunction Blackford Pond March 26 2012

With the pond so still there were a lot of reflections from the trees but where was the moon reflection? Moving right to the edge of the pond revealed where it was and with a little playing about with the composition and waiting for a swan to move away which was causing ripples I got a respectable shot of the reflection in the pond.

Same settings as the previous shot but -2/3ev and ISO3200. The super high ISO was required to get as fast a shutter as possible to freeze the movement of the gentle ripples in the water to stop the reflection distorting. This isb’t a major problem with high end DSLR’s these days but some old cameras will give very noisy shots at this high an ISO.

Reflected Conjunction

Final shot of the night was a closer in view of the reflection, again a high ISO was required and I also switched on the VR on the lens, which you wouldn’t normally do on a tripod but it did help. After many goes, I finally got a shot with a proper moon shape and pin point stars.

Reflected celestial triangle

To finish up with, here’s a quick shot of the Jupiter Moon conjunction the night before, if you look very close next to Jupiter and around 4 o’ clock there is 2 tiny pin pricks of light, 2 of Jupiter’s moons.

Moon, Jupiter conjunction, earthshine and Jupiter moons

Next time you find a nice clear night and you’re looking for something new to photograph, why not see how you get on with the stars? They are far from the easiest subjects to photograph thanks to the Earth rotation but with a little practice you could be adding extra depth to night landscapes.


First tentative steps with Astrophotography

Well, I knew it was going to happen. This tale kicks off back in early December when I made my first ever attempt at a star-trail image, it never happened that night as cloud rolled in but I did get a natty shot of the Forth Bridge and the Big Dipper next to it in the sky. That was the start of the near obsession with the night sky.

Winter is a difficult time for me photographically, especially a winter with little or no snow like this year. Sunsets are difficult, due to working when the sun in setting and the position of the winter sunset is tricky in Edinburgh to so I typically resort to night-time shots and to be honest, I get a bit fed up with photographing the city at night so I needed something new. That something new turned out to be the oldest thing I could photograph, our universe.

Since that night I’ve progressed though star-trails, photographing star fields, the Milky Way, the planets the ISS and anything else astro related I could manage with my current photography equipment but I still lacked one thing, mega zoom!

I needed a telescope. So I bought one for the exorbitant fee of £30 from Jessops. Now, I didn’t expect much from a £30 Jessops junior telescope with a 50mm front on it. What I didn’t reckon for was how bad it actually was. This spindly thing was dreadful and nearly put me off a telescope all together. It was so frustrating to use. I went off the idea since then and started looking at a Sigma 150-500mm lens instead, which combined with my Sigma 2x teleconverter would have gave me a 1000mm lens, 1500mm on the crop sensor. To be honest I’d have bought this but I lacked the £800 or so I needed to get one.

Then Gumtree happened. Up popped a Meade 4504 114mm Newtonian Reflector and motor-driven equatorial mount. The usual Googling was done and off I went to see it. As soon as I laid eyes on it I knew I was buying it. It was huge and that’s what matters right? £80 paid and off I went with my bazooka sized new toy. Satisfyingly filling the boot and back seat of the Mondeo it looked perfect, there was even a camera adapter with it. Glorious up close moon shots were just around the corner, or so I thought.

If you’ve never used a telescope on an Equatorial mount before then you are well unprepared for how difficult it is to get the thing pointing where you want it to. Then when you discover that your 2nd hand bargain has had a harder life than you first thought the bubble slowly starts to burst. Over the next 2 days I discovered that the mount won’t lock in place, a real pain, once you located an object it requires little more than a gnats fart to move the scope and lose the object. Not that bad with the moon but a real bollock ache with the planets.

No matter thinks I, it’s got a motor drive that’ll fix the problem! 10, yes 10 AA batteries later and the motor drive whirred into action. It works, yes. But wait, shouldn’t the mount actually move when I tell it to? Scratch that, it doesn’t work. So, I now have this massive malfunctioning telescope sat in my shed, the wife wont let me keep it in the living room. To be fair, it’s that heavy I don’t really want to carry it from the house to garden to use, 8ft out the shed is much better so there it lives under an old blanket.

Much as I was disappointed by the mount I still figured I could at least get some moon shots with this setup. That’s when I got a stark lesson in focal lengths of telescopes. No matter what I do I cannot get the D90 to focus when attached to the telescope, either using the prime focus or eyepiece projection methods. It seems as if the camera is too far from the telescope mirror. I tried every combination but nothing worked. I’ve since read that using a 2x Barlow lens might correct the issue, I’ve got one of them so that’ll be the test for tonight.

All in, it’s been a frustrating and disappointing experience so far, I didn’t expect to jump right in and be photographing details on Saturn or distant galaxies from day 1 but I had hoped at least for a sharp shot of the moon filling the frame. I’m treating this as part of the learning curve for now, I had similar issues when I first delved into proper long exposure photography but with a little dedication I did get there in the end.

But, and there has to be a but. This post sounds fairly negative, it’s not been the best of experiences but there has been a massive positive. Even with the scope not perfect, I’ve managed to observe the moon really close up, right into individual craters and even a view of the moon on the lowest magnification is awesome, it’s so sharp. A truly breathtaking sight. If that wasn’t enough I’ve also observed Jupiter and close enough in to pick out the moons and the coloured bands around the planet. Something which amazed my youngest son too. I’ve also seen Saturn and the rings around the planet, a sight so awesome it’s hard to describe. When you think about the distances involved in where these objects are its mind boggling.

Even if this telescope never takes a picture for the views I’ve had so far it’s been worth it alone. I’ve seen things that relative to the amount of people on the planet, few have seen. I get fairly awestruck seeing historic landmarks you’ve only heard about of seen pictures off, places like the unfinished cathedral in Barcelona, the leaning tower of Pisa, Pompeii to name a few but seeing Jupiter and Saturn? That’s quite a special feeling and one you can get from your back garden with an £80 investment.