Friday, 3 July 2015

During My Trip To The UK,

I chatted with Lee about his hobby,


astronomy, well he sent me a few of his pictures, like this one of the moon, so much more detail that the ones I take with my camera, unfortunately I do not have a camera mount for my telescope,

speaking of which this is Lee's telescope, it is a Skywatchers 150 on a motorised equatorial mount, handset attached, this picture was taken at Greenwich observatory to picture the last solar eclipse in the UK, naturally there is a solar filter on the telescope,

video
and if you look carefully you will see Lee behind the presenter in this Sky News report of the lead up to the event,

moving further away from the moon and the sun, this is the Orion Nebula, a mass of hydrogen gas compacting with gravity to produce stars, in the middle slightly overexposed stars are being born, the gas has a mass of 2000 of our suns and is huge measuring 24 light years across and 1300 light years away, if you stood on the equator and flashed a beam of light, in 1 second the beam would have travelled around the earth 7 times, a light year is the distance that a beam of light would travel in a year, Lee took this picture using a Canon 550d on 150mm reflector scope no lenses, he took 35 x 40sec  exposure ISO speed at 1600m then a further 25 'dark' pictures to make a complete picture, all of the ones of the object are layered in a stacking program and added together, each picture has the object and background 'noise' as it is called, the 'dark' pictures are what the camera itself takes, no object, just noise which are then used to improve the picture by taking one from the other, some times you may find your own camera doing this you take a picture but in the viewfinder there is a countdown going on before you can take the next picture, 5,4,3,2,1, that is your camera taking a dark picture and processing in camera for you, 

this is a ring nebula, Lee took 20 x 45sec and 20 darks again stacked using a stacking program, the object is 2.5 light years across but 2400 light years away, this star exploded and is very slowly expanding, Lee lives just outside of South East London where the sky is heavy sodium light polluted so removing the lens in his camera there is a cut out in the throat of the camera that a sodium filter can be dropped in to, but be careful, only a few Canon bodies can do this and there are even fewer lenses that you can use as the lens couplings will foul the filter, Lee uses a company called First Light Optics for his supplies, just one other small thing, you may think you set your cameras focus to infinity, you may see this symbol on the lens , well if you do every picture of the star or system that you are taking will be out of focus, you do actually have to focus on the object, the sky at night, all from a back garden in south-east London, well done Lee, I know just how difficult and time consuming taking these few shots will have been.


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