Astrophotography

Toryglen-boy

Toryglen-boy

Toryglen-boy

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Joined
7 Nov 2002
Posts
2,863
Location
Glasgow / Canberra
Anyone here do astrophotgraphy? Here are some images i have taken, not fantastic, but not bad either, i use a Canon 1000D, through a Baader MPCC to correct coma, on a 200mm Newtonian F5 OTA, on an EQ6 mount, guided with PHD through an ST80 F4 refractor, using an Orion starshot Auto Guider.



NGC6357, Nebula in Scorpio, known as "The Lobster Nebula" i remember it doesnt rise in the UK, being just below the horizon, this is a stack of around 40*10min lights, with darks and flats.
ngc6357mix4.jpg




M8, The Lagoon Nebula in Sagittarius, this one does rise in the UK, although not terribly high above the horizon, this was 20*6min lights, with darks etc.
lagoon10m.jpg




NGC 7293, known as The Helix Nebula in Aquarius, this is a gas shell from a dying star, and is one of the more closer planetary nebulas to us, at 6,500 light years.
helix3.jpg




M16, known as The Eagle Nebula in Northern Sagittarius/Scutum. This is a massive region on dust and gas where stars are born
m16.jpg




The moon! rising over the hill, and shinging through some ghost gum trees
moonlight.jpg






hope you like, if anyone else takes any astropics, then it would be great to see them

thanks

:)
 
Mud said:
Those're amazing...this is something I'd really like to get into, but I fear it's just not practicable in the city. Nth'ing more detail on the gear please :)
Click to expand...

ok ...

the whole lot sits on an EQ6 equatorial mount, that is, a mount where the declination axis is adjustable to your latitude, in my case, 33 degs. south, so this axis always points at the south pole. The mount has 2 motors, that drive it along at a sidreal rate (the same rate of the rotation of the earth) so basically, the object is always in the file of view. Ontop of this, is a 200mm (8") newtonian telescope, which is quick quick, with a widefield (F5), this has a 2" focuser, where there is a Canon 1000D, with a T-Ring, connected to a camera adapter, with a Baader MPCC (Coma Corrector) attached to the end. Ontop of that is a small 80mm F4 refractor, that has an Orion Autoguider on it, this is basically a mono CCD that takes an exposure every second, and guides on a star of your choice, this plugs into the mount, and basically says to the mount "ok, i am tracking this star, left a bit, down a bit" and keeps your selected star in the crosshairs. Its all guided with a program called PHD on a HP6220 Laptop, so this keeps the object centred indefinetly, the Canon 1000D takes a series of 10 min exposures, with an Astronmik CLS filter, placed just infront of the mirror on the DSLR, this is a filter that blocks out light on the wavelength of 490 and 510nm, or the slim band of visible light where sodium streetlights live, essentially blocking out streelights, with the filter i can go to about 20 mins before the image fogs, without the filter, its about 3 min.

So, i take a series of 10 minutes exposures, and i stack them in software, this stacking, helps to increase the SNR, and makes fainter detail pop-out, as it removes the noise around it, and increases the strength of the signal. i apply dark frames of the same exposure as a map for overall thermal noise, and flat frames to stop the field being vignetted. The image is then processed in CS4

and voila.

here is the setup.

rig2.jpg



DSCF1431.jpg
 
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