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Archive for the ‘Equipment’ Category

Capturing the International Space Station (and Imagination)

Credit: Mark Humpage

What is it? – The International Space Station or ISS is a large spacecraft which orbits around Earth. This orbit allows the ISS to be reached by launch vehicles (such as the Space Shuttle) of all the international partners for the delivery of crews and supplies. It is the largest and most complex international scientific project in history. The ISS is the size of a football pitch fitted with almost an acre of solar panels that provide electrical power to six state-of-the-art laboratories.

Can the ISS be seen from Earth? – Yes, it travels at an amazing 17,000 mph and orbits earth at an altitude of approximately 250 miles. The sheer size of the structure and array of solar panels reflect sunlight, making it the biggest, brightest object orbiting earth. Only the sun and moon are brighter. It can easily be seen moving across the night sky, at certain times, almost resembling a slow moving fireball.

How do you capture it on camera? – With a bit of planning and the right equipment it can easily be captured on camera:-

Planning – Firstly, one needs to calculate at what time the ISS will pass over the skies above. This can easily be found by visiting a website: www.heavens-above.com which will identify the exact days and times at when the ISS will pass directly above one’s location, and which part of the sky to look. There are also a number of excellent mobile applications such as ‘GoSatWatch’ and ‘Flyby’ which allow this to be done remotely.

Credit: Mark Humpage

Execution – A good ISS capture will require a long exposure. A tripod is therefore required to keep the camera nice and steady. A wide angle lens will ensure maximising as much of the ISS flyby which can travel across the entire horizon. Personally, I use the Olympus 7-14mm or 8mm fisheye which are ideal lenses. Try to locate a foreground object of interest within the frame, a line of trees or buildings in order to give the image perspective and scale. Set the camera to manual and use long exposure times of anything between 15 and 30 seconds. With camera primed and in position all that is left now is to wait for the ISS to enter the field of view. By capturing a single or number of continuous exposures the resulting image(s) will reveal a long trail across the frame. Capturing numerous and continuous images will allow you to stack and produce a composite, which can produce stunning results.

ISS Double flyby photo (bottom) – For this ISS double flyby image I chose a location that offered a good foreground subject (water) and scope to cover the entire east/west horizon. Planning involved choosing an evening where the ISS would fly over my location numerous times (in one night) and a look at the weather forecast to ensure clear skies. Armed with a one man tent and all my camera gear I headed off and arrived on site late evening on June 11th. The first ISS pass was due at 2300hrs and subsequent passes every 90 mins. The plan was twofold 1) Set up one camera waterside and take continuous 15sec exposures for the entire night 2) Use a second camera for each ISS pass in different locations at the site. In between passes I would grab a short power nap huddled in the tent. Not a very comfortable evening but the resulting images made up for it. Using stacking software I produced two composite images, one detailing the ISS passes alone and the other including a star trail from the entire evening.

The star trails and bright light (moon) is the resulting visible effect of earth’s rotation. The location choice was also perfect as the morning mist makes for an eerie scene, perfectly complementing the ISS pass. The images made the national press the following day, which was very pleasing. One final word about capturing the ISS – it is due to be decommissioned (crashed into the sea) in 2020, so be quick!

Captured with Olympus E5 & 8mm fisheye – 2 ISS flybys, each comprising approx 12 images. Final stacked composite Credit: Mark Humpage

#Meteorwatch Competition

Faulkes Telescope

WINNER @bethlovescake

Win a chance to have Nick Howes (@NickAstronomer on twitter) equipment consultant for Astronomy now image your favorite object using the almost Hubble sized mirror of the amazing Faulkes Telescopes. One in Hawaii one in Asutralia…the choice is yours?

He will even process the image and submit it to the Astronomy Now magazine gallery.

For every Perseid meteor spotted and tweeted over the next two nights for the Meteor Map, each tweet will be entered into the #meteorwatch competition and the winner randomly selected.

So don’t forget to tweet #meteorwatch, 1st part of your postcode, Country code and how many meteors you just saw.

Share your #meteorwatch experience and have fun 🙂

Robotic Telescopes

Faulkes Telescope operates a network of research class robotic telescopes. Currently there are two telescopes, one in Hawaii and the other in Australia each with mirrors nearly the same size as Hubble costing £5,000,000

2011 © Copyright Faulkes Telescope Project, official partner of Las Cumbres Observatory Global Telescope Network

Meteor Watch – Catching Perseids On Camera

Credit: Mark Humpage

Meteor Watch, 2011. Well it’s that time of the year again. The air is warm, days are long, Noctilucent are departing, which can mean only one thing – Meteorwatch is back.

There are many subjects within our night sky that are fascinating to watch and equally challenging to capture on camera. However, there really is something quite exciting and magical about spotting balls of fire streaking across a star filled sky. Maybe my affinity with severe weather and, in particular, lightning was the catalyst for fascination, or perhaps the fact that objects the size of a grain of sand can ironically put on such a grand fireworks display. History, in the form of a meteor shower 200 years ago is said to have inspired Samuel Taylor Coleridge’s lines from his famous poem The Rime of the Ancient Mariner. It’s amazing to think that distant evening, when Coleridge was walking along the Somerset coast witnessing the upper air burst into life, would inspire others as we once again prepare for showers.

Whilst there are many displays throughout the year, the most visible meteor shower is the Perseids which light up the skies around mid August each year and offer peak shows of more than 1 meteor every minute – a perfect viewing event. The moon cycle can invariably weaken the viewing event (depending on phase) but even so the challenge of course is not necessarily to witness but to capture on camera. With this in mind, let us look at some useful pointers which will help camera owners increase their odds of pulling off a meteoric masterpiece over the coming weeks.

Credit: Mark Humpage

Firstly, what Camera Equipment is required? Let’s not pull any punches. To capture a decent meteor image will require a good quality camera. Shooting a subject in low light or darkness will require a camera that allows full manual control of the settings and interchangeable lenses. In this respect a dslr fits the bill perfectly. Talking of lenses, my ideal selection would a choice of two (or both). A wide angle, something in the range of *7-14mm (14-28mm 35mm equivalent) together with a lens to get a bit closer, such as the *12-60mm (24-120mm 35mm equivalent). I’ll talk about why I suggest these two lenses a bit later within the technique section. Another pre-requisite piece of equipment is a tripod. This will give stability for those long exposures, and prevent motion blurring. Finally, I would recommend using a cable release or remote method of triggering the camera shutter. Combined with a tripod for steadying this will minimise camera vibration – you would be surprised how much vibration is created by simply pressing the shutter release button with your finger!

Camera Settings – It’s important not to forget our camera subject which is essentially a fast moving bright object visible for a very short period of time. Successfully capturing a meteor with a short exposure time, in darkness, is near on impossible because timing will be down to luck (extremely low odds) and the foreground (for wide angle shots) will be too dark. In this respect, and to increase our odds of a successful capture we need to use a long exposure time. To do this firstly set the camera to manual mode (M). Now set the exposure time to between 15s and 30s (15s for continuous and 30s for single shooting – I will explain this more in the technique section) and shutter speed to the lowest setting (a good quality lens should get down to F2.8). Set the ISO to 500. This will be good starting point for most cameras. Bear in mind that camera systems and models vary tremendously depending on the technology inside, such as the sensor and processing engine. Personally, I have found 15s-30s is sufficient to capture the duration of a single meteor. Combined with a mid value ISO of around 500 will provide sufficient light to deliver a pleasing image of both foreground and subject whilst keeping noise (grainy effect) to a minimum.

Camera Technique. I must reinforce the fact there is a great element of luck in capturing a meteor on camera. One can advise on the optimum camera equipment and settings but there is never any guarantee of success. The key is not success but rather improving ones odds of success. I can certainly increase your odds and results by using the following techniques, based around lens choice. Firstly and desirably find a location away from populated areas and light pollution. Set up the camera with a Wide Angle Lens and try to position an on object in the foreground, such as a tree or man made structure. This will add perspective or scale to an image. Position the camera/lens to cover the north east skyline keeping a small portion of land in the bottom third or quarter of the frame. Ensure focus is set manually to infinity. Using a 15s exposure time and remote cable (set to lock) pop the camera into sequence shooting and hit the shutter release button (If you don’t have a remote cable simply keep the finger pressed on the shutter release button, although it will get numb quickly!). This effectively primes the camera to take continuous frames until you switch the camera off (or the battery runs out). What you will end up with here is as many (or little) images as desired and which can be imported into stacking software. A final composite image could be as long as the night combining a star trail effect with hopefully a meteor or two. If using this technique a good tip, to improve composition, is choose a foreground subject with something of interest and paint it with light. This can be done simply by setting off a few rounds of flash remotely whilst the camera is shooting or waving a lit torch around the foreground.

Pros – Excellent success rate of meteor capture with good image composition.

Cons – Captured meteors will appear small, with little detail against a wide angle frame.

The second technique involves using a lens with greater focal length or Zoom. The far end of a mid level zoom range would suffice (60mm or 120mm 35mm equivalent) or, if available, a high end zoom lens allowing anything up to 200/300mm (400/600mm 35mm equivalent).

Once again manually set the focus to infinity and use a 30s exposure time. Train the camera/lens on an area of sky alone and fire away as and when you feel. To start, concentrate on an area of north-east sky near the Perseids radiant (see Perseids section) but do vary the location all around the sky.

Pros – Captured meteors will fill the frame with great detail (and colour).

Cons – Low success rate of meteor capture (due to small area of sky concentration)

In addition, do experiment by adopting the 15s continuous shooting technique with a zoom lens. This will also increase capture odds. Personally, I shoot with two cameras using both these techniques to really maximise the odds of capture, composition and detail.

The Perseids are meteors which appear to originate from a point within the constellation of Perseus in the north-eastern sky. This point, known as the shower’s radiant is a good starting point for aiming the camera lens. Do note that one might see a meteor anywhere in the sky but the direction of motion, when traced back, will point to the radiant. A meteor that does not point back to the known radiant for a given shower is not considered part of that shower. Locating the Perseids’ radiant is very simple and situated in the constellation Perseus, just below the familiar ‘W’ of the constellation of Cassiopeia.

Finally, it is worth making a quick point about Iridium Flares. Sometimes it is hard to tell the difference between an Iridium flare and a meteor. (See top photo). Iridium Flares are common communication satellites which illuminate when the sun reflects off their bright antennas. Usually the brightness, colour and trajectory are a giveaway (noticeably brighter in the center and dimmer at its ends). Iridium flares can also be accurately predicted (http://www.heavens-above.com) and which is the best indicator for confirming, as long as you note the time, direction and elevation.

May all you showers light up!

Mark Humpage July 2011

* based upon  Olympus E-system 4/3 sensor camera

Credit: Mark Humpage

 

Imaging Perseids with an iphone

ISS with an iphone

Between the 11th & 13th August the perseid meteor shower will once again be visible. This will peak on Friday night when you can expect to see many metors burn up in the upper atmosphere. Its an impressive sight, and one that you can not only see, but capture on your camera, in fact you can get some great shots with only an iPhone!

You’ll need an iPhone 3G along with the Slow Shutter Cam app from Cogitap Software, its 69p and well worth it. This allows the shutter to remain open for a longer period of time, and hopefully catching a meteor. Just open App Store on your phone and download! (I’m sure that there are similar apps for Android phones too)

To take full advantage of this app I would recommend getting your iPhone set up on a tripod. I have been using an adapted generic (cheap) car windscreen mobile phone holder. I sourced the correct sized nut and glued it to the holder. I can then attach it to any tripod, although normally use a jobby gorilla grip on it.
These elements are all you need to use your iPhone to shoot great shots!

The settings I have been using to catch the ISS are
Capture Mode = Light Trail
Shutter speed = B (Bulb)
This should work for the meteors..
I would also recommend you enable the Screen Shutter function that allows you to tap anywhere on the screen to take a shot..

ISS with an iphone

iPhone Astrophotography: My First Attempts

This evening I decided to try some iPhone astrophotography. This blog post will let you see how I got on, and give you the info you need to get started yourself.

While the iPhone 4 camera is far from ideal for astrophotography (the sensor is small compared with a DSLR; in fact it’s not even as good as most point and shoot cameras) it does have one distinct advantage – it’s usually very much to hand, just in my pocket in fact.

There are two kinds of astrophotography you can do with an iPhone: with and without a telescope. The former is called afocal astrophotography, but it is the latter that I tried out tonight: just using the iPhone camera, some extra hardware, a 59p app, and a clear sky.

Afocal Astrophotography. Simply hold the camera to the eyepiece of a telescope (or binoculars) and snap a picture of whatever is in the field of view. For this you can just use the standard camera app on the phone to snap a picture, and it’ll use software to ensure that the image is exposed correctly (although this might not always work). I’ve tried this once before, using the Moon as my target, with decent enough results:

Pic of the moon taken on my iPhone 3GS held to the eyepiece of my 110mm TAL-1 telescope

You can also buy several apps that claim to allow you to take longer exposures, even letting you use a bulb setting (this isn’t actually possible with the iPhone shutter hardware – each of these apps is actually using a clever software work around, but you’re not getting a true 60 second exposure when you set your “shutter speed’ for 60 seconds).

The apps that I use are:

Slow Shutter Cam: has shutter speeds of 0.5, 1, 2, 4, 8, 15? and a B (bulb) setting, plus a crucial self timer delay to prevent wobble when pushing the “button” to take the shot (£0.59 on iTunes App Store)

Magic Shutter: has shutter speeds of 1, 2, 4, 8, 15, 30 and 60? and a B (bulb) setting, but no self timer (£1.79 on iTunes App Store)

Both of these apps have a variety of software setting to allow you to get the best picture; tonight I used Magic Shutter with a 60s shutter speed.

(These apps might allow you to take better images while the camera is mounted to a telescope, but I haven’t tried this yet. Watch this space for test of this later in the year.)

Afocal Astrophotography Hardware

The main obstacle to taking long exposure shots with the iPhone (apart from the fact that the hardware won’t actually let you!) is that you need to make sure that the iPhone doesn’t move at all during the duration of the exposure, so holding it in place with your hand isn’t an option. Luckily there’s a great gadget available from a company call Magnilux. The device is called the Magnilux MX-1 Telescope Adaptor, which allows you to attach your iPhone to any telescope eyepiece. It also doubles as a tripod adaptor.

 

Magnilux MX-1 Telescope Adaptor

 

Magnilux MX-1 Telescope Adaptor with iPhone 4 attached (works with any iPhone model)

 

Magnilux MX-1 Telescope Adaptor configured as a tripod mount

Astrophotography Without a Telescope

Tonight I didn’t connect my iPhone to my telescope since my target, the International Space Station (ISS), moves so quickly and travels across such a large part of the sky that you need as wide a field as possible to catch it.

To capture the ISS you need a long exposure (use Magic Shutter app – see above). The pass tonight lasted 4’19?, and traveled 90° through the sky (from 254° WSW to 164° SSE). The iPhone 4 camera field of view is only 60.8° so I couldn’t capture the whole pass. Instead I decided to try to capture a 60s exposure as the ISS rose to its highest and brightest, at 206° (SSW).

With a 60? exposure, of course, I had to have my iPhone mounted to a tripod. I could have used the Magnilux MX-1 Adaptor set up for tripod mode (see above) but instead I opted to use my new Kungl iPhone case with built in tripod thread, which I attached directly to my tripod.

 

Kungl iPhone Case

This held the iPhone still, and using the Magic Shutter app set to 60? exposure I managed to get this image:

 

The ISS passing over, iPhone 4 Camera, Magic Shutter App set for 60″ exposure, 2344, 23 June 2011

Far from ideal, but not bad given (a) it was my first attempt, (b) I had one chance to take the image before the ISS faded from view, (c) the sky was very bright (this was taken at 2344 on 23 June 2011, just after midsummer, with the sky just out of civil twilight), (d)  cars kept driving past (note the light art in the foreground!).

Once the sky darkens again later in the year I hope to test this set up under a truly dark sky to see whether it can pick up sharp star images. I suspect that might be tricky!

If anyone else has tried iPhone Astrophotography please let me know in the comments.

AstroParty

23rd to 30th of October 2011

In celebration of its 5th year, the Salisbury Star Party will be hosting AstroParty with 7 days of Astronomy activities for people of all levels of interest and ability. All are welcome and those who attend will enjoy dark skies, a fantastic location, great company and lots and lots of fun. The organisers intend to make the Astro Party one of the biggest and best astronomy events in 2011 and beyond.

Venue:

The event will be held in a lovely and spacious campsite in the pretty village of Sixpenny Handley in the glorious Wiltshire countryside, (an area of outstanding natural beauty) with dark skies and excellent facilities including a large cafe/ conference area.

The site is located within 300m of the Village High Street. There are a variety of shops, including General Stores/Newsagents, Butchers, Post Office, Gift Shop and also a Public House. The village church backs on to the campsite, which adds a little more of that country atmosphere to the venue.

The historic City of Salisbury and the market towns of Blandford Forum, Wimborne Minster, Shaftesbury and Ringwood are all easily reached within 30 minutes drive.

If you aren’t keen on camping, there are local B&B’s and hotels etc in the surrounding area.

Activities:

Star Party – Running for all of the 7 nights with around 70 to 100 experienced astronomers at its core, the Star Party is the main part of the event, so bring your kit if you have any, join in and take advantage of observing and imaging with a large group, whatever your level of experience? You don't even need to bring a telescope, just use your eyes.

Imaging World Record – More info coming soon?

Inflatable Planetarium Shows – Big planetariums with big shows all topped off with what’s up guides.

Talks – A daily program of talks by famous and experienced people in the world of astronomy.

Tweetup – A social gathering of social media. Twitter and Facebook users meet and tweet with your online friends here.

Tours of the Sky – live and real tours of the sky by experienced astronomers.

Telescope and Equipment Workshops – Ask for advice or get help with astronomical equipment.

Trade Stands – More info and who is coming soon?

Competitions – A raffle for that nice telescope or piece of imaging kit?

Hospitality – There will be a hog roast on the final Saturday, and there is a cafe which is open through the week. We hope to have additional tents where you can warm up, tweetup, get a coffee, have some soup, or somewhere to chill and drink your beer. There is a licensed bar on site and a pub in the village.

More activities and services will be added to the program before the event starts.

A website will be launched shortly where you can look for additional information and book your tickets for the event.

Please book tickets here 

Let’s Make AstroParty, hosted by the Salisbury Star Party one of the biggest and best astronomy events and we hope to see you all there.

 


Choosing a New Telescope – GoTo or not GoTo

Originally Posted on Universe Today by meteorwatch (@VirtualAstro)


I am often asked by people “I’m a beginner, so what telescope should I buy?” Or more often, what GoTo telescope would I recommend for someone starting out in astronomy?

When venturing out and buying your first telescope, there are a number of factors to consider, but because of glossy advertising and our current digital age, the first telescope that people think of is a GoTo.

Do you really need a GoTo or would a manual telescope suffice? In order to make a good decision on what telescope to buy, you need to decide on what you want to use the telescope for — observing, photography, or both and does it need to be portable or not? This will help you make the best decision for the mount of your telescope.

GoTo telescopes are usually advertised as being fully automatic and once they have set themselves up, or are set up by the user, they can access and track and many thousands of stars or objects with just a simple touch of a button. These features have made GoTo scopes are very desirable with many astrophotographers.

Manual telescopes are not automatic or driven by motors as GoTo scopes are. They are predominantly used for observing (using your eyes instead of a camera) and the scope is moved by hand or by levers by the user to find different objects in the eyepiece. Manual telescopes usually have a finder scope, red dot finder or laser finder to aid in finding objects in the eyepiece. They are unable to track objects, which can make them unsuitable for photography.

GoTo Vs Manual
Compared to GoTo telescopes, manual telescopes are much more economical as you are basically buying a very simple mount and an optical tube assembly (the telescope tube, or OTA). With GoTo you are adding electronics and control mechanisms to drive the scope, which can add heavily to the cost. A small GoTo telescope could cost the same as a lot larger manual Dobsonian telescope.

Good GoTo telescopes make astrophotography very accessible and enjoyable, especially with the addition of cameras and other kits. As opposed to manual scopes, GoTos can be used for long exposure astrophotography. Be aware though, that much astrophotography is done with very expensive imaging equipment, but good results can be achieved with web cams and DSLR cameras.

Manual telescopes are brilliant at helping you discover and learn the sky as you have to actually hunt or star hop for different objects. I once met a person who had been using a GoTo telescope heavily for a year, and at a star party I asked her to show some kids where a well known star was with my laser pointer, she didn’t know because she was used to her GoTo scope taking her to objects.

So which one should you buy?
I would recommend for pure visual observing a manual telescope such as a large Dobsonian or Newtonian telescope. The human eye needs as much light to enter it as possible to see things in the dark, so a big aperture or mirror means greater light gathering and more light entering your eye, so you can see more. What you saved by not having GoTo, you can spend on increasing the size of your telescope.

If you want to add photography or imaging capabilities then I would definitely recommend a good quality GoTo scope or mount. You will get a smaller aperture compared to the manual scope for the same money, but the scope will track for astro-imaging and can also be used for visual observing. Be prepared to spend a lot more money, though.

Consider how you want to use your telescope and the size of your budget. Avoid buying low end, cheap, budget, or what is known as “department store” telescopes to avoid disappointment. Save up a little longer and get a good telescope. Visit your local astronomy store or telescope distributor and before you buy ask an astronomer, they will be glad to help.

I hope you enjoy your new telescope for many years to come :)

Dobsonian Telescope