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08-18-2013, 01:44 PM   #646
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QuoteOriginally posted by Stone G. Quote
Marvellous Dr_who.

What is the f-ratio of your Newtonian?
It's a F3.9 Newtonian.

08-18-2013, 03:14 PM   #647
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Here is a crop of my M45 image showing UGC 2838. It's tiny, and at mag 17.89 is pretty darn faint. I can't find much on it other then it's location and distance of around 300 million lightyears, which would make it by far the farthest item I've ever caught on a image.
If you can't find it, it's the tiny sliver the size of a star on the far right

http://stevenkovickart.com/astro/images/demo/m45_ugc2838crop.jpg
08-19-2013, 04:04 PM   #648
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NGC 6755, NGC 6756, and SH2 74 in one frame

Last month after working on the large M16 mosaic, I grabbed a few nights of data nearby. I was curious how Sharpless2 74 would look along with the open clusters NGC 6755 and 6756. I was surprised to see the dark lanes crossing the region as I had not expected to get this level of detail in a suburban location.

One of the nights was mostly lost due to being out of focus, but it did help to smooth the overall background. There were transparency variations through the sessions, so it's not as contrasty as I'd prefer. Also, I may have oversharpened since I see dark rings around some of the brighter stars (even with using a star mask to control this effect).

17 sub exposures at 1200 seconds at 100 ISO on the modified and cooled Pentax K10D camera.
Stellarvue SV4 telescope with flattener and IDAS LPS filter.







Fullsize link on Astrobin allows pixel peeping
08-25-2013, 11:04 PM   #649
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Iris Nebula August 2013

Another project done in the back yard in the early part of August: the Iris Nebula, named because of the similarity of the central dust clouds appearance as similar to the flower. Very deep exposures of this region show the clouds that obscure the stars glowing in reflected starlight like brown puffs of smoke.

This is a the result of a stack of 36 exposures each at 1200 seconds at ISO 100 using my modified and cooled Pentax K10D on the Stellarvue SV4 scope.

My back yard is a light polluted location with streetlights and neighbor light trespass. Luckily, using light pollution filters and working on targets in the one part of the sky least effected helps. Transparency for these evening was pretty good - could even see a hint of the milky way.







Full size on Astrobin allows pixel peeping

Did a different method of processing on this one, using a new tool in PixInsight, TGVDenoise.


Last edited by smigol; 08-27-2013 at 09:28 AM. Reason: removed tag
08-27-2013, 07:36 AM   #650
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Nova Delphini 2013 ("me-too")

Well I cannot compete with smigol, dr-who and all the other great astrophotographers in this thread, but I have fun anyway.

So yesterday I was out on my balcony with my O-GPS1 and my FA 50mm 1.4 lens experimenting how to get the most out of the Milky Way under my urban, light polluted sky. As at this time of writing, it turns out something like this:


Stack of 8 images in DSS. 20 second exposures at f/2.8 and ISO 3200.

Considering that I cannot see anything but the faintest traces (and only near Zenith and only because I know it is there), I am actually quite happy.

But at an impulse, at the end of the session, I trained the lens at the Dolphin way down in the smog and I actually got this:


Stack of 5 images of 20 seconds at ISO 800 and f/1.4. (Cropped and downsized)

A closer look shows the nova right in the center of this crop:


Approximately 80% crop of original stack.

It may be of interest to compare with this screendump from Cartes du Ciel - and yes, I am confident that I have captured the nova where CdC shows no star.



This is nothing to brag about, but I am still happy that I got my own memory of Nova Delphini 2013. It is with such images as with kids: Others may be prettier and wiser, but there is nothing like having your own.
08-27-2013, 08:31 AM   #651
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Very nice Stone, for light polluted sky the photos are very sharp and full of detail. Sometimes the challenge is worth even more when the results are unexpectedly good.
Hank
08-28-2013, 02:50 AM   #652
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QuoteOriginally posted by oneeyedhawk Quote
.....Sometimes the challenge is worth even more when the results are unexpectedly good.
Thank you very much oneeyedhawk. And, come to think of it, you're right: Working with the challenge is indeed (sometimes) very inspiring and fun in itself.

It certainly inspires me to explore as well lenses and camera settings as the potentials in image post-processing with the fairly simple tools (DSS and PhotoImpact) that I have.
09-01-2013, 01:07 AM   #653
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Pelican Nebula IC 5070

Here's another classic target from early August. I shot just two frames before the clouds came in. Didn't get more data at the time so I didn't work on the image for a while. I learned a few new tricks with PixInsight and so I tried returning to this set and was pleased enough with the results.




Fullsize on Astrobin will allow pixelpeeping

Taken using my standard setup: Stellarvue SV4 scope with the modified and cooled Pentax K10D camera using an IDAS LPS-P2 filter.

09-03-2013, 04:21 PM   #654
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very cool Stephen...what ISO did you use and does the cooled K10 reduce the noise quite nicely...I use the K10 at 800...going to upgrade to the K5 eventually but you`ve given me an idea for the K10...again ...beautiful capture
09-03-2013, 04:22 PM   #655
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M31

Went to a local star party, and thought it would be a good time to practice doing a mosaic as I've never done one. So this is as simple as a mosaic can be with just 2 panels so maybe it's more of a stitch than a mosaic... either way clear skies but very muggy, dew shield helped prevent any dew on the mirrors, but I don't think the sky was not fog free. And being a star Party lots of people walking around with red flashlights, the right side has about 40% more fames (24 minutes worth). But for on here or a small print it won't matter but enlarged you can see it is definitely grainier on the left half side.

Camera: Pentax K5IIs
Scope: 8" Newtonian F3.9
Stacked/merged in Pixinsight
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PENTAX K-5 II s  Photo 
09-04-2013, 12:51 AM   #656
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Really nice Dr Who. I've found that mosiacs really depend on getting high quality calibration with flats to smooth out the gradients. Having good overlap helps a lot, too, no less than 30% coverage seems to do the trick.

Brian: I use my K10D at ISO 100. I have a tracking mount and guide camera so I can really push the exposure duration. As you know, there's a lot of amp glow in the K10D and keeping that from saturating is important to being able to calibrate it out. The cooling I use required cutting open the camera at the base and putting a copper finger into contact with the chassis of the body. While it does not cool the CCD directly, it does reduce the overall temperature inside the camera to help the electronics from generating too much noise. EXIF temperature readings are misleading, so I am still working on a good library that I turn over pretty often.
09-07-2013, 06:54 PM   #657
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This summer, I picked up a couple of older m42 mount takumar lenses (1:3.4/135 mm and a 200 mm) and thought I would attach the 135 to my kx and have them run piggyback on my atlas mount while imaged with my modded Canon/203mm newtonian. I trained my gear on the Veil complex and over the course of 2 nights, I was able to amass 78 usable 4 and 5 min exposures. I did a quick stack in dss and this is what came up.

I am pretty happy with this, but I think I will take a stab at this same target with the 200mm attached to the Canon to try to pull out more detail.
09-19-2013, 10:27 PM - 1 Like   #658
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Pacman Nebula in Cassiopeia

This is a large area of nebulosity near the bright star Schedar in Cassiopeia. The apparent size is about the size of the full moon.

Taken over a series of several days in early September from the back yard this picture is a sum of 18 sub exposures of RGB data with 6 subexposures of Ha data. The Ha frames were taken using a Baader Ha filter to limit the wavelengths of light.

Taken with the modified and cooled Pentax K10D camera with the Stellarvue SV4 scope. The camera was operating at an EXIF temp of 17C most of the time. I'd like to believe that it was actually a little lower than that because of the low standard deviation of the noise profile. Ambient temperatures were mostly 15-20C.

As I had taken the Ha and looked back at them, I was less impressed with how they looked. Of course, everything is all red. I had expected this effect. Splitting out the Red channel seemed to have a reasonable signal level. The other channels were lacking in detail. I'd hoped that the bayer filter would not get in the way of the extended reds of Ha. Seems that this is only the case for NIR.




For comparison, here is the Ha only data:



You can also see these on Astrobin in full size:
Ha | HaRGB
09-21-2013, 11:56 PM   #659
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IC 1396 August - Sept 2013

Taken over several nights from August 27 through Sept 4 set up in the back yard using my standard gear: Stellarvue SV4 scope and modified and cooled Pentax K10D.

A very large stack of sub exposures really helped boost the signal to noise ratio: 66 subs were used for a total of 22 hours of integration.




Full size link on Astrobin allows pixel peeping

This target is so large that it exceeds the size of the frame for this camera and scope combination. A 300 mm lens would hold the entire area well and I may try to get this in the near future. Otherwise, I will return to make a mosaic.
09-23-2013, 12:21 AM   #660
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IC 5146 - Cocoon Nebula

The Cocoon Nebula or IC 5146 is a star-forming region in Cygnus.

Taken over the course of two nights in early September at a nearby dark sky site (Montebello Open Space Preserve). This is the sum of 22 sub exposures for 7 hours of integration. Again, using my standard setup of the 4 inch apo scope with the cooled Pentax K10D camera.




The annotated image identifies the background galaxies that are well beyond the Milky Way.




Full-size on Astrobin allows pixel peeping.
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