PDA

View Full Version : Messier object 42 - The Great Orion Nebula


Recty
02/02/2016, 01:45 PM
I took this from my brother's house in Palmer which has a view south. Unfortunately, I cant see south from my house thanks to some mountains. Sadly, that is where some of the coolest stuff in the night sky is... Oh well :)

This is 20 images at 360 seconds each, stacked for a total of 2 hours of exposure time.

http://i73.photobucket.com/albums/i236/Recty/integration_DBE1_16bit_Final_Small_JPG.jpg~original (http://s73.photobucket.com/user/Recty/media/integration_DBE1_16bit_Final_Small_JPG.jpg.html)

The large nebula on the right is M42, the one on the left is called Running Man. If you tilt your head to the left 90 degrees, you'll be looking at the Running Man in the orientation that makes the most sense.

M42 is about 1350 light years wide, just to give some scale to the image.

Recty
02/02/2016, 02:06 PM
Oh and if you're wondering if it's cold where I'm imaging at... here's my setup :)

http://i73.photobucket.com/albums/i236/Recty/ColdScope.jpg (http://s73.photobucket.com/user/Recty/media/ColdScope.jpg.html)

Sk8r
02/02/2016, 05:17 PM
Wow. Great pic. WInter skies. And that would be frost on that lovely instrument.

Fishbulb2
02/02/2016, 08:06 PM
That is really cool. Makes me want to get out the telescope. You must have really accurate sidereal tracking to have those images align so well correct? Or do you use software to align them?

Recty
02/03/2016, 01:26 AM
Wow. Great pic. WInter skies. And that would be frost on that lovely instrument. That would be a LOT of frost on the scope, yes.

That is really cool. Makes me want to get out the telescope. You must have really accurate sidereal tracking to have those images align so well correct? Or do you use software to align them?
I have a guide scope attached (it's the small scope on top/right in the picture with the two cables going into it) that helps track perfectly. And then yes, I do use software to stack the images afterwards.

Common misconception is that stacking 10 pictures produces a picture that is 10 times as bright as one. That isnt true. It just reduces the signal to noise ratio, which allows it to become nice and clear and less noisy, so then you can process the picture to bring out the faint wispy stuff.

Toads74
02/03/2016, 01:59 AM
Nice pic! Got some great detail!

Been having the itch to get the scope out for a while. The frost brings back those single digit nights where my eyebrows would freeze to the eyepiece. :)

snorvich
02/03/2016, 04:47 AM
Great picture. Have you considered heat straps with a controller for your equipment?

Recty
02/03/2016, 10:28 AM
Great picture. Have you considered heat straps with a controller for your equipment?

Yep, and they are being used in that picture. If you look at the main scope, right where the lens would sit (at the back of the dew shield, the widest part of the telescope) you see a strap and no frost in front of or behind it.

My two small scopes mounted on top are also basically frost free, and in the front where it matters they are frost free, you can see dew heaters wrapped around there as well.

Fishbulb2
02/03/2016, 09:37 PM
That would be a LOT of frost on the scope, yes.


I have a guide scope attached (it's the small scope on top/right in the picture with the two cables going into it) that helps track perfectly. And then yes, I do use software to stack the images afterwards.

Common misconception is that stacking 10 pictures produces a picture that is 10 times as bright as one. That isnt true. It just reduces the signal to noise ratio, which allows it to become nice and clear and less noisy, so then you can process the picture to bring out the faint wispy stuff.

Thanks Recty. I'm unfamiliar with the how you use a guide scope to do the tracking. Do you have a link for that? I have a small guide scope on mine as well, but I thought you simply first do polar alignment and then just use a motor to maintain sidereal tracking. I'm just curious now.

Super cool images.

FB

Sugar Magnolia
02/05/2016, 10:05 AM
Holy wow, that is an amazing picture!!

noy
02/07/2016, 11:53 AM
wow amazing picture. awesome setup.

Just curious why the photo stacking? What is the effect you were after?

Recty
02/08/2016, 01:42 PM
Thanks Recty. I'm unfamiliar with the how you use a guide scope to do the tracking. Do you have a link for that? I have a small guide scope on mine as well, but I thought you simply first do polar alignment and then just use a motor to maintain sidereal tracking. I'm just curious now.

Super cool images.

FB Thanks. As far as a guide scope goes, I use PHD2 with the guide scope to track. I'd get on youtube and search for PHD or PHD2 tutorials and it will teach you how to guide much better than I ever could.

Holy wow, that is an amazing picture!! Thanks!

wow amazing picture. awesome setup.

Just curious why the photo stacking? What is the effect you were after?
Photo stacking improves the signal to noise ratio. It doesnt improve "brightness" like you might think it would, otherwise you could just take 1 photo and stack it 10 times in Photoshop and have an amazing image. Instead, with every exposure the digital noise moves around in the background. The more you stack, the more the stacking software has samples of what is real data and what is noise and other extra data that you dont want in your picture. It keeps all the "good" and gets rid of all the "bad" and leaves you with a much cleaner and less noisy image. Then you go on to photoprocessing and bringing out all the faint wispy details without bringing it so high that it blows out the bright objects. It's a balancing act that cant be done without multiple stacked exposures to reduce noise.

noy
02/08/2016, 11:11 PM
Nice technique - using image stacking median/means to reduce noise. Going to have to try that out on high ISO shots.

Recty
02/09/2016, 01:22 AM
The sweet spot for most DSLRs for long exposure astrophotography is ISO800, just btw. I know with short exposure images it matters greatly what DSLR you have, but for anything approaching 5-10 minutes, ISO800 is the best for about everything. Smarter people than me have done the math behind it.