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A Cone And A Christmas Tree

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Description

There is a H-Alpha region, a region full of ionized hydrogen, somewhere between Gemini and Orion, in the constellation of Monoceros. It's not far from the Rosette Nebula. The ionized hydrogen is the red nebulosities you can see on my image.

The Cone Nebula, so named because of its apparent shape, is a dark nebula made of cold molecular hydrogen and dust in front of the ionized hydrogen.

You can see the Christmas Tree cluster with a binocular. It is formed by the most brilliant star roughly in the center of the image. The rest can be seen only on photos


32 exposures of 5 minutes. 8 darks, 8 flats.
Camera : Canon EOS 1000D unfiltered
Telescope : Takahashi FSQ-106ED refractor.
Mount : Takahashi EM-200 USD3.
Guiding : Orion Starshoot Autoguider on a William Optic Zenithstar 66SD refractor.
Outside temperature : 0.5°C to -3°C
Sensor temperature : 3°C
Software : auto-guiding and acquisition with MaximDL, pre-processing with Iris, processing with photoshop.
Location : Col des Milles Martyrs, France
Image size
1000x667px 408.41 KB
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Comments42
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octane2's avatar
:star::star::star::star::star-half: Overall
:star::star::star::star::star: Vision
:star::star::star::star::star: Originality
:star::star::star::star::star-empty: Technique
:star::star::star::star::star-half: Impact

Sylvain,

Isn't it amazing what fast optics and decent high-ISO sensor performance can get us nowadays? Images like this would have been only within reach of the most high tech observatories only a few years ago.

I love the composition. Usually, you'd be berated for not following the Rule of Thirds, however, this rule I don't think particularly applies to astrophotography, unless, the object(s) you're imaging are framed in such a way that they can follow the rules. The Cone Nebula and Christmas Tree Cluster in the middle of the image really works well, here. The blue reflection nebulosity is balanced so well with the brighter stars of the cluster. It's grand that nature had intended this region of the sky to be presented in such a way. The scattering of the brighter stars in the field give a sense of depth.

The colour and saturation in this rendition strikes me aesthetically pleasing. The lush red tones give warmth to what we otherwise consider as cold compositions. Are you using IRIS' "black" command to set your white point? How are you colour balancing? G2V stars? In either case, the colour looks right to me. Of particular note is the glamorous saturation of the starfield. Oftentimes you'll find images with no colours in stars whatsoever, and, the stark whiteness of the stars often detracts me from enjoying what otherwise may have been a nice image. You've struck a good balance here. There are a couple of things which could be dealt with, though; you have some interesting aberrations around the brighter stars. The FSQ-106ED is one of the finest colour-corrected scopes ever made, and should not be exhibiting these halos. Might this be the result of aggressive use of the "asinh" function or did your focus shift throughout the night?

Contrast is in great abundance and shadow detail is beautifully maintained. One thing of note is that the top right sky background is a slightly lighter shade than the bottom left. Residual gradient not flat-fielded out? In either case, the bottom left almost appears to be clipping the shadows. The dust to the left-centre could be brought out a bit more.

Noise appears to be well-controlled (excepting a couple of shadow regions, particularly in the Cone) but, you would expect good performance operating the camera in freezing temperatures.

Just one technical capture piece of advice I can give you is to take lots and lots of dark frames, flat light frames and flat light dark frames. I aim to reach a signal-to-noise ratio of 3-5 (4-5, typically). That is, 9-16, or 16-25 frames of each. The more images you have, the better the calibration results.

Congratulations, my friend. This is your best image to date.

Regards,
H