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Pages: 1 [2]
Author Topic: Astrophotography  (Read 11298 times)
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light pollution is ruff these days ,all the new streetlight LED's are extra crispy ...
when it comes to Lumens and street safety the Light rules the night .

   
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Posts: 327
... for the LED streetlights.  And that damn thing is _bright_.
You could approach the offending streetlight with a ladder and a tin of black paint and improve the edges where the beam is useless anyway.
   

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Posts: 2037
Why I don't like driving at night these days, the led tail lights give me red eye :'(

Regards

mike 8)


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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860

As a general rule, the most successful person in life is the person that has the best information.
   
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opportunity knocks, this time a photo opp next time perhaps a real knock??

http://www.newsweek.com/potentially-hazardous-asteroid-3200-phaethon-will-pass-earth-sunday-and-you-750356
   

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Posts: 1298
Have you seen the stars tonight?



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"The easiest person to fool is yourself" -- Richard Feynman
   

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Posts: 573
nice shot TK. What lens?
   

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Posts: 1298
Thanks!
I've lost the full image data (stacking, exposure times and numbers) but I used the William Optics Megrez 90 apo refractor, at about 600mm fl and f/6.5, and the TeleVue field flattener/reducer, into the Canon DSLR. Took a handful of image frames, some dark frames and some flats, stacked them all together in DeepSkyStacker, then processed the result in PixInsight and gimp. The diffraction spikes on the brightest stars come from a little trick: A "crosshairs" set made of black thread that I mounted on the front of the telescope.

Capturing the bluish nebulosity around the main stars of the Pleiades has been a real challenge for me. I captured a bit of it in that image, but there is much more that can be caught. I'm still trying....


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"The easiest person to fool is yourself" -- Richard Feynman
   

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Posts: 1298
I came across this video tutorial today. It's a demonstration of Darktable, a freeware photo editing package, as applied to astrophotography.

http://www.youtube.com/watch?v=_Yq60o5yQsg

It's kind of long and he goes really fast, but I couldn't look away. He also has some more basic tutorials on his channel, so that should keep me busy for a while.



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"The easiest person to fool is yourself" -- Richard Feynman
   
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Posts: 2337
  Fascinating video  O0   
Thanks, TK.
   

Hero Member
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Posts: 573
Thanks!
I've lost the full image data (stacking, exposure times and numbers) but I used the William Optics Megrez 90 apo refractor, at about 600mm fl and f/6.5, and the TeleVue field flattener/reducer, into the Canon DSLR. Took a handful of image frames, some dark frames and some flats, stacked them all together in DeepSkyStacker, then processed the result in PixInsight and gimp. The diffraction spikes on the brightest stars come from a little trick: A "crosshairs" set made of black thread that I mounted on the front of the telescope.

Capturing the bluish nebulosity around the main stars of the Pleiades has been a real challenge for me. I captured a bit of it in that image, but there is much more that can be caught. I'm still trying....
wow nice work indeed. What's the max exp time you can get on that combo and not leave star trails?
   

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wow nice work indeed. What's the max exp time you can get on that combo and not leave star trails?
Thanks! Depends on how carefully I can get the mount aligned, (Celestron CGEM) and whether or not I am using guiding.  Two or three minutes when not guiding, and basically unlimited if guiding (using Stark Labs "PhD" "push here dummy" guiding software and the Orion Short Tube 80 guidescope setup).  My main problem with long exposures isn't usually tracking or guiding accuracy, but rather "skyglow" from all the light pollution hereabouts. And it's worse now that they have changed all the streetlights to LED. I have a photographic filter that cuts sodium and mercury vapor lighting but it doesn't work so well with the new LED light spectra.  So ten minutes per exposure is pretty much my practical limit due to light pollution.  But if something happens (and it often does) then I lose time, so I generally limit to 5 minutes max and just take a bunch of frames and stack them in DeepSkyStacker (Free software) or Stark Labs Nebulosity (not free but worth the cost). I generally use Nebulosity for controlling the camera and saving the frames. DSLRshutter is another free application from Stark Labs that works well if all you need to do is to control the DSLR exposures and sequencing.
A few years ago I installed a concrete pier for the mount so I don't have to use the tripod. It's a lot more stable, but when a truck goes past I still get vibration that can ruin an exposure. It's a tradeoff: Longer exposures mean a given incident of vibration doesn't affect the image as much, but longer exposures also mean more chances for vibration to happen during the exposure.
I also have Maxim DL (quite costly, "professional" amateur astrophoto software)  but it is so complicated that I never actually use it.
So, when seriously imaging, I have the mount connected to the laptop, and I'm running PhD with the Orion guidescope to keep the system on target, and Nebulosity to control the camera and save the exposures.  It's a maze of cables. Laptop > USB hub > mount, guidescope camera and imaging camera.

This is the result from a stack of ten-minute exposures of the Rosette nebula, taken with the Parsec monochrome cooled CCD camera.



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"The easiest person to fool is yourself" -- Richard Feynman
   

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You could approach the offending streetlight with a ladder and a tin of black paint and improve the edges where the beam is useless anyway.

Heh... that's a good idea, especially now in winter that the trees have shed leaves and no longer block the direct view from the light to my observayurt ... but it would probably get me arrested!    ???



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"The easiest person to fool is yourself" -- Richard Feynman
   
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Posts: 327
Heh... that's a good idea, especially now in winter that the trees have shed leaves and no longer block the direct view from the light to my observayurt ... but it would probably get me arrested!    ???
There are some new LED street lamp heads which are very directional and much more energy efficient. You might be able to  persuade the local authority to swop them in. It will pay them in the end. I may be able to provide precise details but not for a couple of weeks.
   

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wow TK that's great info. I'm yet to get a scope, it's on the list though. I'm pretty lucky with light pollution here. I'll be going wide before going deep. A Samyang 14mm 2.8 is also on aforementioned list :)
   
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Imagine finding some of this?

a piece from the solar system before it was formed.

https://www.yahoo.com/news/mysterious-ancient-egyptian-rock-made-091001866.html

 

   
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