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02-19-2013, 05:25 PM   #526
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M81/m82

Here's a view of M81/M82 as seen in the backyard on the night of Feb 16 2013.

It's a stack of 10 subs at 100 ISO, 1200 second duration. Camera was my modified and cooled Pentax K10D. Exif temp was reported at 4C, thermal probe was set to about -3C, so it was pretty dang cold.




Large on Astrobin

I've got a pile of other data that I'm playing with to see if I can eke out a dim nebula (Sh 290). If I can get something presentable, I'll post it.

FWIW, here's a cropped version of the above to show near 100%.



To see 100%, go to flickr and touch L. I didn't want to upload the full 1601 pixel wide shot here.


Last edited by smigol; 02-20-2013 at 10:55 AM. Reason: added near 100% view.
02-20-2013, 09:09 AM   #527
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You did a nice job on the image of M81/82 Smigol

I've been wanting to go out but the weathers been overcast for weeks
02-20-2013, 02:00 PM   #528
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Smigol, that's excellent!
02-22-2013, 12:48 AM   #529
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Going Deep (and ugly)

I've been messing with a deep, dim object for testing and while it's really ugly, it does show what can be done with a lot of subs and patience.

To give an idea of how dim this object is, take a look at just one 1200 second sub at 100 ISO:


See how the histogram is well clear of the left side, indicating that the exposure is now limited by skyglow. The amp glow is plainly visible in the upper part of the frame, showing the limits of this K10D. Even at 4C, this glow remains visible. The pixel value readout in the floating window to the upper right (34, 41, 38) is from the center of the screen. Also see that the nebula is not visible, even though it's in the dead center of the field of view. After collecting a ton of these shots over nearly 10 nights, I had something to use.

Once I stacked up the data and put it through calibration in Maxim and then DSS, I could see that PixInsight's STF tool showed the nebula plainly, even though it was just above a ton of noise:


The image on the left is the stack just after DBE, the image on the right is after a bunch of work to stretch and mask for noise reduction and curves. This stack is from 76 subs - each at 1200 seconds at 100 ISO, just like the one above, for a total of 25 hours of integration time.

My final - at least until I get data under a darker sky than home - is this one, where I reworked the curves:



It's ugly. The sky is mottled because of the local light pollution. I can't drive this down because even after stretching, the nebula is still just barely above the noise.
See how the "after" picture in the side by side is darker, but much of the nebula is lost compared with this final version.
There are dust motes that cause light spots from mis-matched flats. This is not surprising because I was working on tightening mount screws and messing with the camera cooler, so I missed a day or two of flats.

I'm looking forward to some easy galaxies in Virgo.

02-22-2013, 01:00 AM   #530
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QuoteOriginally posted by smigol Quote
I've been messing with a deep, dim object for testing and while it's really ugly, it does show what can be done with a lot of subs and patience.

To give an idea of how dim this object is, take a look at just one 1200 second sub at 100 ISO:


See how the histogram is well clear of the left side, indicating that the exposure is now limited by skyglow. The amp glow is plainly visible in the upper part of the frame, showing the limits of this K10D. Even at 4C, this glow remains visible. The pixel value readout in the floating window to the upper right (34, 41, 38) is from the center of the screen. Also see that the nebula is not visible, even though it's in the dead center of the field of view. After collecting a ton of these shots over nearly 10 nights, I had something to use.

Once I stacked up the data and put it through calibration in Maxim and then DSS, I could see that PixInsight's STF tool showed the nebula plainly, even though it was just above a ton of noise:


The image on the left is the stack just after DBE, the image on the right is after a bunch of work to stretch and mask for noise reduction and curves. This stack is from 76 subs - each at 1200 seconds at 100 ISO, just like the one above, for a total of 25 hours of integration time.

My final - at least until I get data under a darker sky than home - is this one, where I reworked the curves:



It's ugly. The sky is mottled because of the local light pollution. I can't drive this down because even after stretching, the nebula is still just barely above the noise.
See how the "after" picture in the side by side is darker, but much of the nebula is lost compared with this final version.
There are dust motes that cause light spots from mis-matched flats. This is not surprising because I was working on tightening mount screws and messing with the camera cooler, so I missed a day or two of flats.

I'm looking forward to some easy galaxies in Virgo.
Excellent job Smigol. Wish my Comet Lemmon shots were half as good as this.
02-22-2013, 04:06 AM   #531
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Still feeling out my locations/settings/etc. I'm finding the O-GPS1 to be annoyingly finicky to get set just right so you don't wind up with trails, even with the UWA.

That said, when it DOES get things right...

Second shot was taken about a hundred feet to the left of the first, to try to get the mess of white park lights out of fram and cut down on that flare. I'm sure with a bit more practice I'l be able to figure a way (somewhat) around it. This will probably bemy primary shooting location unless I decide to drive somewhere. Above the bright sodiums to the left across the river is a hillside that offers an open view to the west which I can walk to and use as well if I decide to walk a bit more.

FWIW, I like how I can make out (albeit faintly) the Milky Way in the lower left of the sky.





02-22-2013, 08:26 AM   #532
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Amazing work Smigol- you inspire me greatly. Nice to see you're getting used to your O-GPS1 Sagitta. I have yet to have a clear night to try mine out. Can't wait tho. Clear Skies to ALL!!!
02-22-2013, 02:03 PM   #533
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QuoteOriginally posted by GWARmachine Quote
Amazing work Smigol- you inspire me greatly. Nice to see you're getting used to your O-GPS1 Sagitta. I have yet to have a clear night to try mine out. Can't wait tho. Clear Skies to ALL!!!
Last night was pretty much the first night that was clear (and stayed clear) since I picked the unit up about 2 weeks ago. Hilariously (in a no, not really way) while I was trudging around in the thin snow getting shots I hit a patch of ice and went feet-up for a moment. I saved the K-30, and watched in horror as my open camera bag (with my Nexus 7 in it) took a high lobbing arc, only to have the Nexus skitter out across the ice for about 15 feet while I heard a SNAP somewhere in the process.

The snap was the tripod - everything else survived unscathed (surprisingly, even myself - I went down hard since I had to keep one hand up in the air to keep the K-30 and Sigma 10-20 from crashing down with me). I'd had the camera attached to the tripod since I was just relocating from one spot to another, and when I hit the release plate smashed its way through the plastic housing in the tripod head.

We're far enough in the lunar cycle that I may be able to try some window-shots of the moon tonight. My living room windows face almost due east so I get some pretty nice views sometimes of the rising moon. I'm also due to get my new (to me) M-200mm so I can play with that and my 2X teleconverter.

02-22-2013, 04:11 PM   #534
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Leo Triplet

This is the last shot from me from my data during February.

As a part of collecting testing information on some flexure work, I started grabbing frames of the Leo Triplet (M66 M67 NGC 3628). Same weather conditions as the previous two submissions: clear, cold, mostly dry.

I pulled in 31 good frames at 1200 seconds each 100 ISO for 10 hours of integration from Feb 13 to Feb 15.



Same setup as before, same camera, same telescope.
I also tried to use similar processing to show the background galaxies even though the sky would show a muddy red color.

Click to get the 100% view of the central crop.

02-22-2013, 04:42 PM   #535
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Wonderful shots smigol. It's difficult to comprehend that you did this with just an 8" reflector. I'd love to see what you could do with a 20" or larger. I can only admire your dedication.. 10 hours of data is a serious commitment.
02-22-2013, 06:10 PM   #536
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QuoteOriginally posted by bossa Quote
Wonderful shots smigol. It's difficult to comprehend that you did this with just an 8" reflector. I'd love to see what you could do with a 20" or larger. I can only admire your dedication.. 10 hours of data is a serious commitment.
Thanks Bossa!

Nearly all my shots are with a 4 inch (102 mm) apo refractor at F6.5, so it's smaller than an 8 inch reflector. It just makes the shots a little longer to get decent data.

Many of my insanely long integration times are done at home where I can set up the computer and then go inside where it's warm and just monitor how things are going with VNC. Once morning comes, I'll wake up and put the scope to sleep.
02-22-2013, 09:24 PM   #537
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QuoteOriginally posted by smigol Quote
Thanks Bossa!

Nearly all my shots are with a 4 inch (102 mm) apo refractor at F6.5, so it's smaller than an 8 inch reflector. It just makes the shots a little longer to get decent data.

Many of my insanely long integration times are done at home where I can set up the computer and then go inside where it's warm and just monitor how things are going with VNC. Once morning comes, I'll wake up and put the scope to sleep.
Sorry for the mix-up re' gear. I must have confused you with one of the other members here.

It's utterly amazing that you can actually see some detail in the spiral arms of these galaxies with a 4" refractor. Your work is inspirational but I doubt I would stay the distance for more than a few months.

With the level of skill you possess I wonder if you might have thought about doing some research?
02-22-2013, 11:36 PM - 1 Like   #538
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I use a 8" reflector, but I agree it's amazing what details you can pull out of even "wide angle" telescopes. Some objects are quite big but obviously very dim, hence the long amount of subs. This image is with same camera and scope.

http://stevenkovickart.com/astro/sizecomparison.jpg

Last edited by Dr_who; 02-23-2013 at 09:55 PM.
02-23-2013, 04:37 AM   #539
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Nice pictures everyone!

I'm so jealous for you guys having those clear skies. This winter has been all cloudy for me. This month there has been total of 8 hours of sun shine. Last month was little better (28 hours) but in December there was only 3.5 hours of sun shine in whole month Hope this weather gets better so I could use my o-gps and recently acquired Tair 3s 300mm.
02-23-2013, 01:48 PM   #540
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Hooked my adapter up to my scope, stuck my camera in... and had the whole scope jut sag southwards.

The mount can't support the weight of the K-30.

I may see if I can get creative - I bought the scope as much for terrestial viewing as stars, and with the O-GPS1 unit I *should* be able to cheat and just set the camera to having an 800mm and see how things fare (the scope is a 910mm).
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