Jump to content

 

1825338873_SNRPN2021banner.jpg.68bf12c7791f26559c66cf7bce79fe3d.jpg

 

Chocolate Brownies: LDN 1228 & LBN 552


mftoet
 Share

Recommended Posts

I like sweets (ask @ollypenrice), especially chocolate. A lot of chocolate coloured molecular clouds can be found in the wonderful constellation Cepheus. This is the area of LDN 1228 (on the left) and LBN 552. Shown here is the full field of view and a crop that zooms in on LDN 1228 and LBN 552 to show the dark dust clouds in more detail.

Captured during two nights (August 14 and 15) from the dark site of Olly's 'Les Granges' in Étoile-Saint-Cyrice.

Total integration time: 6 hours, 10 minutes (74x 300s subs) | Optics: Takahashi Epsilon-180ED f/2.8 | Camera: Nikon D810a (ISO 400) | Mount: Astro-Physics Mach1 GTO3 guided with a Lacerta MGEN and Vixen 70S guidescope | SQM: 21.4 - 21.5 magnitude/arcsec² 

Data reduction and gradient removal / background correction in AstroPixelProcessor using 30 flats and 200 bias frames. I don't use dark frames but apply (excessive) dithering. Post processing in Adobe Photoshop and PixInsight.

i-Sg4JPK7-X5.jpg

i-BfqW648-X5.jpg

  • Like 32
Link to comment
Share on other sites

That is simply glorious dust. Lovely to see the denser and more tenuous dusty objects next to each other as well. The three dimensionality of the image is also one of its strong points and the blue stars show that the full colour range has been captured.

Regarding sweets, did you know that The Lounge on SGL has an annual obsession with growing hot chillies? Oh yes!! The perfect antidote to chocolate...

Olly

 

  • Like 1
Link to comment
Share on other sites

Thank you for your replies.

@tooth_dr: try your D800E on your Epsilon. DSLRs can do a fantastic job with fast optics, especially on a dark site.

@Tom OD (and others mentioning the 3D-look of the browns): no magic was used to enhance the browns. I think the most important step was to carefully correct the background for colour gradients using AstroPixelProcessor's 'Remove Light Pollution' tool. Usually I run several preview iterations (calculations) and keep placing new boxes in the image that look to be 'nebula free' patches of background sky if neccesary. I don't bother about the yellow and red boxes showing up after the calculation. Sometimes I remove them, sometimes I don't. It depends on the result judged by the eye. To make it easier to judge if the colour gradients are properly corrected, I apply a maximum DDP preview stretch during this process. I don't think you can make it perfect with so many dust in the field that differs in brightness, but I find that this tool in APP gives better results than PixInsight's DBE. In the end, I don't process my images for scientific purposes, but to make a picture that's pleasant to the eye.

Another thing that helps giving the browns (or any colour for that matter) a vivid look, is to adjust the saturation slider in APP and/or the vibrance slider in Photoshop's Camera RAW convertor. And then there is 'Match colour' in Photoshop and slight s-curve transformations on the a and b channels in Photoshop's 'Lab colour mode'.

Here's the RAW stack in APP (DDP stretched) to show you what was my starting point.

i-6Wqx9xn-X3.jpg    

Edited by mftoet
typos
  • Like 3
Link to comment
Share on other sites

6 minutes ago, mftoet said:

Thank you for your replies.

@tooth_dr: try your D800E on your Epsilon. DSLRs can do a fantastic job with fast optics, especially on a dark site.

@Tom OD (and others mentioning the 3D-look of the browns): no magic was used to enhance the browns. I think to most important step was to carefully correct the background for colour gradients using AstroPixelProcessor's 'Remove Light Pollution' tool. Usually I run several preview iterations (calculations) and keep placing new boxes in the image that look to be 'nebula free' patches of background sky if neccesary. I don't bother about the yellow and red box showing up after the calculation. Sometimes I remove them, sometimes I don't. It depends on the result judged by the eye. To make it easier to judge if the colour gradients are properly corrected, I apply a maximum DDP preview stretch during this process. I don't think you can make it perfect with so many dust in the field that differs in brightness, but I find that this tool in APP gives better results than PixInsight's DBE. In the end, I don't process my images for scientific purposes, but to make a picture that's pleasant to the eye.

Another thing that helps giving the browns (or any colour for that matter) a vivid look, is to adjust the saturation slider in APP and/or the vibrance slider in Photoshop's Camera RAW convertor. And then there is 'Match colour' in Photoshop and slight s-curve transformations on the a and b channels in Photoshop's 'Lab colour mode'.

Here's the RAW stack in APP (DDP stretched) to show you what was my starting point.

i-6Wqx9xn-X3.jpg    

Very helpful.

Olly

Link to comment
Share on other sites

@mftoet thanks the reply. That’s exactly how I use APP, it’s great software.

Your stars look pretty good with nothing but the stretch. My imaging resolution is 2.2”/px, and yours is 2.0”/px, so not much difference. Can I ask what method you use for focusing?

 

 

Link to comment
Share on other sites

15 minutes ago, mftoet said:

I use a Bahtinov mask and focus on a bright star while manually adjusting the focuser and look at the spikes at the live display of the camera. 

Thanks Maurice.  Although I have a motorised Moonlite focuser on mine, I also tend to use a Bahtinov mask also, on a magnified image of a star and focus by moving the focuser with SGPro.  Based on your image which has only been stretched in APP, my stars do seem larger to my eye.  I use a Baader UV/IR cut filter which should be of sufficient quality.  Perhaps sky quality plays a part too

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.