Monthly archives: október, 2016

Rosette Nebula (Caldwell 49), 2016-10-16 processing

Rosette Nebula (as processed on 2016-10-16)

Rosette Nebula (as processed on 2016-10-16)

I used the old raw material as described in this post, but this time I used the new program described here. This is the result.

From wikipedia: The Rosette Nebula (NGC 2237, 2238, 2239, and 2246) is a diffuse nebula in Monoceros. It has an overall magnitude of 6.0 and is 4900 light-years from Earth. The Rosette Nebula, over 100 light-years in diameter, has an associated star cluster and possesses many Bok globules in its dark areas. It was independently discovered in the 1880s by Lewis Swift (early 1880s) and Edward Emerson Barnard (1883) as they hunted for comets.

I also looked up the small open cluster on the lower right of the frame, it is NGC 2236. It is about 9600 light years away, ie about twenty times further than the Pleiades.

Canon 1100D mod, obi de 200mm F/2.8 la F/4, 20×150 sec, ISO 800, EQ3, Dângău Mare, Cluj, 2016-04-03

(tovább…)

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Heart and Soul revisited

Heart and Soul nebulae, processed on 2016-10-15

Heart and Soul nebulae, processed on 2016-10-15

In the camp at the Rotunda Pass, my plan was to acquire hours of light on the Heart and Soul, but the sky thought otherwise. I squeezed out about 8 fair exposures, 4 being with good and 4 with decent transparency (ie less contrast). So the instruments: Canon 1100D mod, 8×3 minutes, ISO 1600 at 200mm F/4 on the HEQ5 mount. I reprocessed the picture with the new star removal tool I developed a few days ago.

(tovább…)

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The Gamma Cygni Region revisited

 2016.10.14. gamma cygni 20160815data reprocessed z final

The gamma Cygni region, reprocessed on 2016-10-14

I wasn’t satisfied with the outcome of my star handling program so I rewrote it. The goal was to obtain an image that is as technically accurate as possible, while contains less artifacts and it is more appealing than the original.

I recorded with the Canon 1100D mod 21×150 sec, ISO 1600, with the lens Canon EF 200mm f2.8L II USM dialed to F/4, mounted on the HEQ5. The main feature is the red glow of the ionized hydrogen region around γ Cygni (the brightest star in the frame) with dramatic gaps caused by clouds of dark nebulae. The Crescent Nebula is also there. The object is also known as NGC 6888, Caldwell 27, Sharpless 105, and is a nebula blown by the Wolf-Rayet star WR 136 (HD 192163) expected to go supernova in the next 100k years.

 

(tovább…)

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How I handle the stars

Veil Nebula, about 4 hours

Veil Nebula, about 4 hours

This post is outdated, this is the new article.

A dense starfield can be the amateur astronomer’s nightmare for it can effectively hide the faint nebula behind it. The more errors add up, the less is reveiled of the target. Why? Because the stars that are supposed to be pointlike get big, lens errors blow up the stars, bad seeing blows up the stars, any amount of dew on the lens or fog spoil the stars while the nebula is still there. So I thought of something: what if I could tune the volume of the stars. Another train of thought arose from an image artifact I keep getting – a panda eye like feature, ie a dark ring around the pointlike luminous stars. These two problems amazingly have almost the same solution: throw out the stars and use the remaining context. The point being aesthetics and not science, I started to brew a software.

(tovább…)

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Rosette Nebula (Caldwell 49)

Rosette Nebula

Rosette Nebula

I reprocessed 20×150 sec, ISO 800, F/4 raws of the Caldwell 49 Rosette nebula using my star handling routine as a step. The camera was the Canon 1100D mod, and the mount the old EQ3. Light acquired on 2016-04-03 at Gyerőfidongó/Dângău Mare.

(tovább…)

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The Veil Nebula, retry

Veil Nebula, about 4 hours

Veil Nebula, about 4 hours

In summer 2015 I acquiered some 4 hours of light with the then unmodified Canon 1100D and the Canon EF 200mm f2.8L II USM. I gave it another try to see how processing the old raw material turns out, deploying my star handling program. I think the result shows improvement.

(tovább…)

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The Milky Way in Cygnus and Cepheus

The Milky Way in Chepheus and Cygnus

The Milky Way in Chepheus and Cygnus

I imaged the Cygnus-Cepheus region of the Milky Way characterized by bright emission nebulae, countless stars and dark clouds of interstellar dust. Deneb with NGC 7000 North America and its neighbour, the Pelican, and gamma Cygni with the nebulae rules the upper right corner of the frame, while on the left the much fainter IC 1396 holds the Elephant’s Trunk. Downwards from the center the Cocoon Nebula ( IC 5146 / Caldwell 19) is also visible, amongst other fainter and less prominent deep sky objects.

This time I used the cheapest lens I have, the Canon EF 50mm f/1.8 II in manual focus mode, which is held tight and in focus by some hard wire I put on it. Although dialed to F/4, it performed pretty well, given the circumstances. In order to avoid having bad corners, I made a mosaic with big overlaps. So the HEQ5 mount held the Canon 1100D mod camera on a ball head, with the lens. 50×3 minutes, ISO 800, F/4. I also used the healing program – source code below.

 

(tovább…)

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Jól kalibrált monitoron mindegyik számnál elkülönülő árnyalat látszik. Ha mégsem látszanak, akkor a megjelenített képek színhiányosan rajzolódnak ki. A monitort valószínűleg kalibrálni kell.

You should see distinct shades for each number. If those shades are not clearly visible, the displayed pictures will lack accuracy. Your display most likely needs to be calibrated (brightness, gamma, contrast etc.).