Monday, 12 May 2014

Orion

Only had two clear skies since moving up to Shetland, but the stars were amazing with very little light pollution. Unfortunately it was too windy for photos and now the days are long with little darkness so it may be a while before i can get any more star photos. I will be adding more sky photos soon. For now its good to remember Orion.

Anyone looking up at the night sky to the south cannot fail to see the Orion constellation. It is recognised by the bright stars of Rigel and Betelgeuse top and bottom. The three stars in the middle are know as Orion's belt and looking closely at the three stars  the Orion Nebula can be seen lower down on what is named as Orion's sword.

Orion is most visible from January - March in the northern hemisphere, but May - July it cannot be seen as it appears in daylight hours.




Orion can be used to locate other stars, by extending the belt south Sirius can be found and like wise north Aldebaran can be located.

The three stars in the belt are

  • Alnitak which is a triple star 736 light years away
  • Alnilam is a large blue super giant the 30th brightest star in the sky
  • Mintaka is 916 light years away and is the faintest of the three stars
Orion Nebula (Messier 42) is possibly the first deep sky object people want to photograph, after all its easy to find and can be seen by the naked eye. The Trapezium is a cluster of quadruple star system and  has many new born stars together with luminous gases and dust make a great object to photograph. It is amazing to find that it is 1,344 light years away and is thought to contain over 1,000 young stars and 700 other stars in various phases. 

The first ever photo of Orion Nebula was back in September 1880 when Henry Draper used an 11 inch refractor telescope to take a 51 minute exposure. It was also the first object that the Hubble telescope observed in 1993

the above Nebula photos are 17 images @ 50 seconds guided then combined.

Friday, 2 May 2014

Reducing Light Pollution


                                                           New light pollution map of Europe

At least most of Shetland, apart from Lerwick, Scalloway and Sullom are reasonably dark sites. I know I keep on about this but in Sheffield light pollution is a major problem, even in the depths of the Peak District you have Manchester at one side, Sheffield at the other.

This makes it impossible to take an exposure of more than 40 seconds otherwise you can see an orange glow appear in the image. Perhaps a light pollution filter might help, or in my case make a drastic move to Shetland where this is less of a problem.
                                       Unprocessed Photo except for noise reduction at ISO 1600


To see the Milky Way and other constellations you need to view from a dark area otherwise the light drowns out the stars. This is also the case when a full moon appears. I have been surprise that many people think that the moon is needed to provide a light in the sky to illuminate the stars, sorry but this is far from the truth.

People often say that you need to be more than 100 miles from a city to benefit, some chance in the UK. One thing to help is to shoot in RAW and then adjust the white balance after, but those shooting in jpeg should set for daylight white balance. Using an Astronomik CLS Filter will reduce the light pollution and bring back the colour of the stars. Don't forget the optimum time for photography is around 2 am when most people have turned their lights off and gone to bed.

While you are out waiting for a long exposure you need something to do, so when not some light painting



                                                                                                                                                      It's me !!!

Sunday, 13 April 2014

Massive Meteor shower due

Make sure May 24, 2014, is circled on your sky watching calendars. On that date, we might experience the most dramatic display of "shooting stars" in more than a decade.

Orbit of Comet 209P/LINEAR
According to predictions, a little-known comet will pass perihelion in early May of 2014 and, two weeks later, sandblast Earth with dust particles spread along its orbit.
NASA / JPL / Horizons
The source of all this buzz is a little-known periodic comet called 209P/LINEAR. Discovered by an automated sky survey in 2004, it follows a looping but relatively tight path that carries it just inside Earth's orbit every 5.04 years. According to dynamicist Syuichi Nakano, Comet 209P/LINEAR's next perihelion occurs on May 6, 2014, at a point 0.969 astronomical unit from the Sun and with Earth not far away. 

Just 18 days later, we should cross through dozens of particle streams shed during past orbits. The predictions are still rough, but three different models suggest the sky show could be spectacular. "All the trails ejected between 1803 and 1924 cross Earth's path in May 2014," notes Jérémie Vaubaillon (IMCEE, France). "As a consequence, this shower might as well be a storm," with the potential to see more than 1,000 meteors per hour under ideal conditions.

That's the same conclusion reached by Russian meteor sleuth Mikhail Maslov, who thinks at least 100 to 400 meteors — and quite possibly many more — should rain down per hour. But he cautions that Comet 209P/LINEAR is small and hasn't been observed much. Moreover, outbursts of meteors linked to this comet haven't been noted in the past.

The potential for a strong showing in 2014 was first pointed out by meteor specialists Esko Lyytinen and Peter Jenniskens, but detailed calculations by Vaubaillon and Maslov have heightened the anticipation.

Although darkness in Shetland will be at a premium at that time of year its worth staying up to see this shower

Friday, 21 March 2014

Moon Phases

The moon always shows the same face to the earth and craters can be seen on the surface. It is the second most luminous planets in the solar system after the sun. Back in 1967 I was at school and witnessed the moon landings, which captured everyone's imagination. there are some that don't believe that the Americans landed at all . the footprints will last for many hundreds of years because there is no wind and no atmosphere to destroy them.

When I look up at the sky at night and see the large searchlight of the moon shining down i cannot fail to be moved. It is approx 239,000 miles from earth yet we seem to be closely connected , i know that the moon is likely to be a part of our planet having been struck by a large meteor which broke a chunk from the earth which eventually became the moon as we know it.

The large featureless plains that can be seen by the naked eye are called Maris or seas, these are really vast solidified pools of lava. These seas cover 31% of the surface on the near side of the moon, on the far side these only cover 2% of the surface.

The light coloured regions are know as the highlands as they are higher than the seas, these have been studied and have been found to be 4.4 million years old.

Craters form a large part of the surface and at the last count there is over 300,000 craters over 1 km in length .

A few days after new moon, when there is just a very slim crescent, you can sometimes see earth shine on the unilluminated portion of the moon .Earth shine caused by sunlight being reflected off the earth and falling onto the moon

                                                                                                                                                          Photos showing earth shine

When photographing the moon make sure that you remove all filters otherwise you will get a reflection as shown the the photo below

Sunday, 9 March 2014

stop moving please

In the last Blog i talked about increasing the amount of night photography time.This one is about a different type of time. If you have ever taken a night photo you will know that the stars move (really its the earth that's moving) and cause streaks so you have to calculate the exposure time based on the lens and camera that are used. Often the calculation is based on the 600 or 500 Rule which i think is better for more rounded starts.
                                                                                                                                                                  That's unless you want a star trail effect as above

Shutter Speed Using the 500 or 600 Rule

Use this table to help you calculate the maximum shutter speed you can use before you’ll start getting noticeable star trails in your nightscape photos.

Use the 600 rule for longer exposures and web images where slight trailing won’t be noticeable, or

Use the 500 rule if you’re more conservative or plan to print your images at 30” or higher.
                      1.5x Crop Sensor                   1.6x Crop Sensor                  Full Frame
                               NIKON                             CANON

Focal Length 500 rule 600 rule                  500 rule 600 rule             500 rule 600 rule

8 mm                42 s     50 s                            39 s        47 s                       63 s        75 s
14 mm              24 s     29 s                            22 s        27 s                       36 s        43 s
17 mm              19 s     23 s                            18 s        22 s                       29 s        35 s
24 mm              14 s     17 s                            13 s        16 s                       21 s        25 s
35 mm                9 s     11 s                              9 s        11 s                       14 s        17 s
50 mm                7 s      8 s                               6 s        7.5 s                      10 s        12 s
70 mm                5 s      6 s                               4 s         5 s                          7 s          9 s



For custom focal lengths, simply divide 500 or 600 by the focal length of your lens.
Example, for a 20 mm lens: 600 / 20 = 30 seconds on full frame, or 600 / (20*1.6) = 19 seconds on a Canon crop camera or 600 / (20*1.5) = 20 seconds on a Nikon/Sony crop camera.

  
For a 2 x crop sensor (bridge or 4/3rd camera)

            500 rule
14 mm  17 s
20 mm  12.5s
30 mm    8s                          
45 mm   5s





Friday, 28 February 2014

Finally

At last some dry weather with clear skies. On Tuesday it cleared late on but I was out giving a talk on Shetland so wouldn't have  been able to do any night photography. On Wednesday night we had already made plans so it was down to Thursday and luckily it was a good clear night but very cold, down to -4 degrees.

When i arrived up at Ringinglow near Sheffield it was just light so I set up asap and thought I was in a quiet spot until around 50 cyclists past in 3 groups, followed by a few cars which lit up the area I was working in. So not a dark site but as I have mentioned before we don't have any true dark site around here



Orion nebula (Red spot)

On Thursday I was lucky enough to see the aurora which was a surprise as i had not received any notification. Seeing the photos the next morning from Shetland you can understand why Sheffield had a glimpse for around 30 seconds. The photos coming out of Shetland were incredible with some fantastic reds and greens, wish we had been there. The aurora activity is only ever 12 years or so with 2014 being the best one, although some activity can be seen at other times.



Friday, 21 February 2014

Double time anyone ?

When you start night photography you will come to see that any time spent photographing is very precious. You are the mercy of the weather and unlike many aspects of photography you cannot plan ahead. Take a look at my calculation and see whether this is about right for you.

365 days a year
- 2 (6 months too light) = 182.5 days
- 10 days a month x 6 months due to full moon and poor weather = 60 days
182.5 - 60 days =  122.5
- 4 days a week (Other commitments ) x 4 weeks x 6 months =  96 days
122.5 - 96 = 26.5 days  per year
4.41 days per month if you are lucky

Talking with many astronomers in and around Sheffield , they usually consider that they only manage about 10-12 sessions a year.(this may be optimal view conditions, you can never tell what the atmospheric conditions are going to be like, well up in the sky ) Therefore I might have over calculated, if you take January and February this year you will have already lost around 7/8 days due to the very wet, cloudy and windy conditions.

So to maximize my chances on good viewing nights i have decided to start to use two cameras on tripods (just picked up an excellent Monfrotto pro tripod for £50) rock solid with a good head. Then I can take two sky objects at the same time. Often one camera will be tied up taking a long exposure so it will keep me busy.

Also the other objective is to move permanently to Shetland therefore increasing my night viewing times. It goes darker earlier and in winter sunrises very late. One problem will be the very windy conditions so the locations will have to be chosen carefully, at least the number of dark sites will increase dramatically. Around Sheffield it is virtually impossible to find one.