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Alnitak region, HaRGB, RGB, Ha + Visual appearance for comparison

Tim

By Tim
in Imaging - Deep Sky

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Tim

Tim

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I don't seem to get to do many imaging projects for myself these days. This year in particular seems to have been particularly lacking in clear dark nights, I don't know if you would agree?

Complicating matters further in my locale has been a huge and long lasting A45 bypass, three years and still not quite finished. The site has been working 24/7, and they put perimeter lights all around the temporary site office complex. At the same time my kind neighbour (who knows what I do for a hobby and for pocket money) decided to install the brightest floodlight I have ever seen, and leave it on all night every night, shining at 90° over my garden....

At any rate, I found some subs that I captured in March of this year using a Skywatcher Esprit 150ED, and Atik 11000 camera. I don't actually remember capturing the data to be honest, so it was a nice surprise to find it on my HDD.

Possibly the most photographed DSO in the sky, the iconic Horsehead nebula is instantly recognisable. For this picture I have combined a little bit of RGB colour data with the bulk of the data gathered with a Hydrogen alpha filter. Recently @ollypenrice posted a lovely picture of the same area, and somebody made a Facebook comment about letting the stars shine out. Which got me to thinking, rather than try an minimise the effects of Alnitak, the huge, hot, blue star on the mid left, I'd just let it do it's thing, dominating the picture, as it dominates in the eyepiece.  Although the flame nebula and rear of the Horsehead are the brightest emission nebulae in the vicinity, the whole area is awash with thick clouds of gas and dust. This image represents the way I imagine the area would look if we could get in a bit closer.

The image represents around 15 hours of Ha data, and 45 mins or so of Red, Green and Blue. Thirty minute Ha exposures.

I've included the Ha image alone, and also a cropped approximation of the actual eyepiece views you may experience in dark skies, with a 16 inch telescope, using a Hydrogen beta filter. I saw this for the first time in the autumn and had of those astro moments that stays with you for a long time. A Hb filter is definitely on my shopping list once I get my dob mirror sorted.

Flaming-Horse.jpg

Horsehead-and-Flame-Nebula-Hydrogen-Alpha.jpg

Visual-Impression.jpg

 

Thanks for looking.

Tim

 

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ollypenrice

ollypenrice

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It's gorgeous. You've gone for more Ha than I did which has given a different look. 

Alnitak is very well controlled just by your optics,  the 6 inch Esprit. It's done a cracking job. In fact my own processing I did  hold down the star to some extent but really most of it was done by the optics as well, TEC 140 in my case. My comments about Alnitak on my post were really referring to what I found it did on other scopes I've used on this target (an old Genesis, the Tak FSQ85 and the Tak FSQ106.) These all produced a massively bright region around the star without layered processing of multiple stretches. Clearly the big apos do well on this kind of thing (and many others...)

Anyway a great result. Hope your sky perks up.

Olly

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Tim

Tim

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26 minutes ago, Owmuchonomy said:

That looks great on my 27" Mac.  Personally, I like the Ha only (mono) rendition best of all.  It makes the Horsehead jump right out at you.  Great stuff.

27" Mac? You should have said, I wouldn't have reduced the size to 40% :D   I was going to upload the full size to Astrobin, but apparently I have used 40 of my allowed 10 images....... :p I recently bought a laptop with enough beans to easily process the 11000's pictures and drizzle them, which is saving me a LOT of time over the old obsy PC.

I too prefer mono images on the whole. I'm fascinated by the structure and substance of nebulae, and only mono images really let you examine them. Not only that, the LP around here means that only narrowband exposures really cut the mustard.

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Tim

Tim

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26 minutes ago, johnrt said:

My favourite is the Ha mono version too, such a shame your unable to get out and image more often Tim.

Thanks @johnrt, In addition to the general lack of clear nights, this year I've had regular commitments to S@N magazine for equipment reviews, and they have to take priority. I've been doing as much astronomy as the skies allow, but much of it is testing and testing and testing and testing............

I'm considering getting an AZ EQ6 just so that I can do some personal astronomy at the same time as using the review gear. Or else my dob's mirror is shortly off for repair so I may end up using that in the back garden. I'm getting more and more into visual astronomy for some strange reason, and have spent more on eyepieces and visual aids in the last couple of years than cameras.......that's not right is it? :p

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Tim

Tim

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7 hours ago, swag72 said:

I really love the mono version Tim..... it oozes quality and a softness that is exquisite. A shame that S@N is getting in your way :( I hope that you can find a comfortable balance in 2017 :)

Thanks Sara. "Getting in the way" is not the way I meant it to come across, more like I am preoccupied with review gear rather than my own, which I dont mind and fully expected. I'm doing more astronomy now than ever :)

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