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Equipment Discussions >> Electronically Assisted Astronomy

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Connor Walls
scholastic sledgehammer
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Reged: 10/05/10

Loc: California
Re: Astro Video Image Gallery new [Re: lunar]
      #5005225 - 01/07/12 01:33 AM

Really awesome images everyone. Can't wait for my adapter to come in so that I can get started!

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Craig in Tacoma
super member


Reged: 01/27/11

Re: Astro Video Image Gallery new [Re: Craig in Tacoma]
      #5007803 - 01/08/12 06:27 PM Attachment (48 downloads)

Here's a nice screen shot from today (Jan 8, 2012)

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Michael Rapp
Post Laureate
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Reged: 04/27/04

Loc: Dickinson, TX
Re: Astro Video Image Gallery new [Re: Craig in Tacoma]
      #5018929 - 01/15/12 01:32 PM Attachment (36 downloads)

We had an exceptionally transparent night last night so I engaged in my odd predilection for hunting white dots that only subtend a few pixels.

Here was the most challenging object for the night, Hickson 20 in Aries. This is a compact galaxy group consisting of six galaxies arranged in a nice "> >" pattern. One of the galaxies (member f) is exceptionally faint and SkyTools puts it at 18.8 magnitude. (Now, there is some error here, sometimes +/- 0.5 magnitude.)

I was able to detect relatively easily all of the members but member f, this one took some doing. After experimenting with my settings, about in one out of every three integrations there was a hint of something in that spot that I believe was not noise, so I've recorded this detection as tentative. (The screen shot below does not show it.)

I'm absolutely beside myself with how cool this is. I'm only 30 miles from the fourth-largest city in the U.S.! (mag 4 to mag 4.5 skies)

Here is my strategy for hunting these tiny dots at the edge of detection:

  • Observe near the meridian so you are looking through the least amount of atmosphere.
  • Have saturation at zero. There's no color here and this way you're not fighting through color noise.
  • Paradoxically, lower AGC. At a typical video focal length, these galaxies only subtend a view pixels. You want to keep noise at a minimum. (Within reason.)
  • Be gentle on contrast stretching/adjustments. We are not trying to enhance large-scale detail, we're just trying to detect. Our focus is on the sky background. Even moderate contrast adjustments can posterize the sky background making detection difficult.
  • Mind your black point. Avoid the temptation to go for that black sky background. The sky background is not black, it actually a light grey due to airglow even in the darkest of skies. In the city, it is most certainly not black.


So here is the screen capture, no post processing other than the labels.

C9.25 at f/5, MCX, Astronomik UHC, 90 seconds, AGC 3.


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Craig in Tacoma
super member


Reged: 01/27/11

Re: Astro Video Image Gallery new [Re: Michael Rapp]
      #5018960 - 01/15/12 01:54 PM

Nice job Michael,

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Dragon Man
Carpal Tunnel
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Reged: 03/07/06

Loc: Snake Valley, Australia
Re: Astro Video Image Gallery new [Re: Craig in Tacoma]
      #5020030 - 01/16/12 04:07 AM

Beautiful result Michael
They show up nicely.

My favourite object! Faint distant galaxy Clusters


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nytecam
Postmaster


Reged: 08/20/05

Loc: London UK
Re: Astro Video Image Gallery new [Re: Michael Rapp]
      #5021264 - 01/16/12 05:37 PM Attachment (25 downloads)

Quote:

I'm absolutely beside myself with how cool this is. I'm only 30 miles from the fourth-largest city in the U.S.! (mag 4 to mag 4.5 skies)


Thanks Michael for great challenge My effort below in 60s - I love these faint fuzzies from the big city - I'm 9 miles from centre of London with 8M

What is the distance of these galaxies


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Michael Rapp
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Reged: 04/27/04

Loc: Dickinson, TX
Re: Astro Video Image Gallery new [Re: nytecam]
      #5022331 - 01/17/12 08:49 AM

Cool, you got f! Your image clearly shows how much dimmer it is compared to the others in the group. I definitely need to revisit it. When I look back, the night may not have been as transparent as I thought it was.

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Dragon Man
Carpal Tunnel
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Reged: 03/07/06

Loc: Snake Valley, Australia
Re: Astro Video Image Gallery new [Re: nytecam]
      #5022410 - 01/17/12 09:51 AM

Quote:


What is the distance of these galaxies




Maurice, the Hickson Compact Group 20 is 620 million L.Y. distant.
http://astrosurf.com/chd/h/hcg20.jpg


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mega256
scholastic sledgehammer
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Reged: 05/10/07

Loc: N of Tampa
Re: Astro Video Image Gallery new [Re: Dragon Man]
      #5022726 - 01/17/12 12:32 PM Attachment (23 downloads)

Orion sky glow imaging filter test.
From last night on NSN..
At12in @F4,mcx 90seconds.From my red/white zone N.of Tampa
From 0 to30 deg up I have a constint light/water vapor glow around my home.Next the UHC filter test..
M82---Orion sky glow imaging filter

Edited by mega256 (01/17/12 12:36 PM)


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mega256
scholastic sledgehammer
*****

Reged: 05/10/07

Loc: N of Tampa
Re: Astro Video Image Gallery new [Re: mega256]
      #5022728 - 01/17/12 12:34 PM Attachment (17 downloads)

M51---Orion sky glow imaging filter


Edited by mega256 (01/17/12 12:37 PM)


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nytecam
Postmaster


Reged: 08/20/05

Loc: London UK
Re: Astro Video Image Gallery new [Re: mega256]
      #5023203 - 01/17/12 04:25 PM

My link to some recent DSOs shots via my tiny Meade 70mm ETX-70 piggybacked scope including M81/82 in 60s, supernova SN2012A and Horsehead Managed a dozen and half DSOs across the sky in <3hrs eg my most productive ever

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Craig in Tacoma
super member


Reged: 01/27/11

Re: Astro Video Image Gallery new [Re: nytecam]
      #5024084 - 01/18/12 02:38 AM

Not bad with an ETX 70, Good job

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mega256
scholastic sledgehammer
*****

Reged: 05/10/07

Loc: N of Tampa
Re: Astro Video Image Gallery new [Re: Craig in Tacoma]
      #5024489 - 01/18/12 11:04 AM Attachment (27 downloads)

This is the same set up,at12in f4, but with a uhc and ir stack..
M82-uhc+ir

Edited by mega256 (01/18/12 11:06 AM)


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Craig in Tacoma
super member


Reged: 01/27/11

Re: Astro Video Image Gallery new [Re: mega256]
      #5024893 - 01/18/12 02:14 PM

It's easy for me to see that I'd choose the Orion Sky Glow over the UHC and IR stack. Details and color balance (to me at least) are in the first shot, much better. Nice work Mega

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Chris A
Pooh-Bah


Reged: 02/03/07

Loc: Toronto, Canada
Re: Astro Video Image Gallery new [Re: mega256]
      #5024973 - 01/18/12 02:58 PM

Good test Bob!! Try this remove the IR filter and just use your UHC filter esp. when viewing the galaxies. Having the IR filter on for me seems to decrease the detail in galaxies and I now go without an IR filter. Always light pollution filters (IDAS-P2, Lumicon DS etc.) tend to show better color and detail when viewing galaxies, however, they are very useful and can surpase the light pollution filters when dealing with severe light pollution or when the moon is quite bright. The UHC filter will always beat a light pollution filter when viewing nebulas. Also try not to clip your background too much by lowering the bright setting beyond where it should be set. If you pull this image into a software program that shows the histogram, you will noticed on the left side the blacks are clipped.

CS

Chris A
Astrogate


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lunar
Carpal Tunnel


Reged: 07/03/10

Re: Astro Video Image Gallery new [Re: Chris A]
      #5027073 - 01/19/12 03:43 PM

Great shots everybody. HCG 20 is spectacular, really shows what can be done with modern technology! Magnitude 18.8 is far beyond what I've ever dreamt of seeing, and was taken by surprise when I saw such faint things here. Very impressive! Wonderful shots of M82 as well.

Clear skies,
Brandon Doyle


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nytecam
Postmaster


Reged: 08/20/05

Loc: London UK
Re: Astro Video Image Gallery new [Re: lunar]
      #5028266 - 01/20/12 09:27 AM

Quote:

Great shots everybody. HCG 20 is spectacular, really shows what can be done with modern technology! Magnitude 18.8 is far beyond what I've ever dreamt of seeing, and was taken by surprise when I saw such faint things here. Very impressive! Wonderful shots of M82 as well.Clear skies,
Brandon Doyle


Brandon - without wishing to spoil the party I think the mags quoted by Michael [and same in Megastar] are unduly faint and may be blue mags. Sloan DSS are typically 1.5-2 mags brighter eg f=m17.05! This would be about right and close to the mag threshold for my camera in these brief exposures

Here's a deeper Hickson 20


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ngchunter
super member


Reged: 10/09/09

Loc: Sarasota, FL
Re: Astro Video Image Gallery new [Re: biomedchad]
      #5028428 - 01/20/12 11:12 AM

Quote:

Bubble nebula with a 6nm HA filter.



Aha, I was wondering if something like this would work for beating extreme light pollution. How long was the integration time?


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lunar
Carpal Tunnel


Reged: 07/03/10

Re: Astro Video Image Gallery new [Re: nytecam]
      #5028487 - 01/20/12 11:48 AM

Quote:

Quote:

Great shots everybody. HCG 20 is spectacular, really shows what can be done with modern technology! Magnitude 18.8 is far beyond what I've ever dreamt of seeing, and was taken by surprise when I saw such faint things here. Very impressive! Wonderful shots of M82 as well.Clear skies,
Brandon Doyle


Brandon - without wishing to spoil the party I think the mags quoted by Michael [and same in Megastar] are unduly faint and may be blue mags. Sloan DSS are typically 1.5-2 mags brighter eg f=m17.05! This would be about right and close to the mag threshold for my camera in these brief exposures

Here's a deeper Hickson 20




Thank you for explaining, that makes sense. I'm willing to bet that after a while you get to know how your camera is going to perform on certain objects based oin their sizes, surface brightnesses, and overall magnitudes. 17th magnitude is still very impressive!

Clear skies,
Brandon Doyle


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Craig in Tacoma
super member


Reged: 01/27/11

Re: Astro Video Image Gallery new [Re: Craig in Tacoma]
      #5037941 - 01/25/12 09:08 PM Attachment (27 downloads)

sunspot #1401 & 1402

enjoy


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