Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

FenlandPaul

Double cluster, heart and soul nebula - feedback please!

Recommended Posts

Hi all, I managed what I'd call my first "proper" attempt at going deep last night, with a shot at the Double Cluster, Heart Nebula and a bit of the Soul Nebula.  Would really appreciate some constructive feedback on this; it's delighted family and friends, but if I'm going to improve I need an expert eye!

I took 208 45s exposures, at ISO800 on a modded Canon 450D with Samyang 135mm lens at f/2.8 (ish), mounted on a Star Adventurer.  Urban / rural transition skies (medium-sized village about 8 miles from Cambridge). Same number of darks (just left the camera running after packing up).

Stacked 95% of them in DSS.  Then processed in Photoshop trying to adopt the approach of Trevor Jones (from Astrobackyard YT channel), but I am quite new to PhotoShop so I find that part a little challenging.

Things I like:

- I've actually captured it!

- Generally I've managed to get the stars reasonably small, at least compared to some fairly hideous Pleiades shots I've done through my 420mm frac before!

- There's a bit of colour in the double cluster stars

- Sitting inside by the fire with a glass of wine while the camera ran! (you can't do that in astro-landscape work!)

 

Things I don't like:

- the vignetting.  Should I have done flats?

- the image still seems a little noisy to my eye.

- the stars in the double cluster aren't very impressive.  Had hoped for something crisper there.  Is that too much to expect from this setup when it's towards the edge of the frame?

- not as much detail in the nebulosity as I'd hoped for.  How much of that is expectation vs experience?

 

I'd really appreciate any help.  I'm mostly interested in astro-landscapes, but I'd like to become reasonably competent at widefield DSLR deep-sky this at the same time!

 

Thanks

Paul

1005854484_20201120PerseusDoubleClusterwithHeartandSoulNebulae.thumb.png.3d875ed7cfb8c912b6f35656e24de868.png

  • Like 5

Share this post


Link to post
Share on other sites

SORRY MODS - I put this in the wrong section.  If it's not too much trouble to move it either to "getting started" or the widefield imaging section, that would be great.  So sorry.

Share this post


Link to post
Share on other sites

Flats are arguabley more important that darks if you are suffering from significant vignetting (and are much quicker to obtain than darks). As you used a fixed camera lens then, since the optical alignment won't change (and assuming you haven't sprayed everything in dust since taking the images), you can still create them after the event and then apply them.

 

  • Like 1

Share this post


Link to post
Share on other sites

Hi Paul, this is great first photo! I have some very modest experience and I'm sure  others will add to it. Here are mine 2cents:

 

For the vignetting: yes you need flats, especially in large DSLR sensors to compensate for the uneven illumination. It's very easy - just put a T-shirt over the camera lens, point to a cloudy sky in daytime and shoot with the same focus and aperture in aperture priority. Just 4-5 frames will do which can be added to the stack in DSS.

The noisy-ness looks more like light pollution to me. There is little you can do apart from moving or buying more gear (filters).

One thing that can help right away is to wait until the area of interest is near the zenith -less air means less glow from the LP. 

The edge of the frame is always going to look worse - even the best lenses have aberrations near the edge and stars are very sensitive.

 

Clear skies!

 

Edited by Nik271
grammar
  • Like 1

Share this post


Link to post
Share on other sites
22 minutes ago, Seelive said:

Flats are arguabley more important that darks if you are suffering from significant vignetting (and are much quicker to obtain than darks). As you used a fixed camera lens then, since the optical alignment won't change (and assuming you haven't sprayed everything in dust since taking the images), you can still create them after the event and then apply them.

 

Thanks - yes, it's a 135mm prime lens.  This sounds like a job for this weekend!  Thank you for the feedback.

Share this post


Link to post
Share on other sites
21 minutes ago, Nik271 said:

Hi Paul, this is great first photo! I have some very modest experience and I'm sure  others will add to it. Here are mine 2cents:

 

For the vignetting: yes you need flats, especially in large DSLR sensors to compensate for the uneven illumination. It's very easy - just put a T-shirt over the camera lens, point to a cloudy sky in daytime and shoot with the same focus and aperture in aperture priority. Just 4-5 frames will do which can be added to the stack in DSS.

The noisy-ness looks more like light pollution to me. There is little you can do apart from moving or buying more gear (filters).

One thing that can help right away is to wait until the area of interest is near the zenith -less air means less glow from the LP. 

The edge of the frame is always going to look worse - even the best lenses have aberrations near the edge and stars are very sensitive.

 

Clear skies!

 

Thank you!  Appreciate that..  Flats sound like a no-brainer then and I should get out this weekend and make some.  The target started off at around 65 degrees and was climbing throughout the session, so it sounds like moving or filters are the next steps there!

Share this post


Link to post
Share on other sites

Thanks to those who provided some feedback.  Managed to capture some flats today and added them to the stack, as well as working on the edit a bit more to remove some of the gradients.  Much happier with this!  Still some noise and parts that I'm not happy with, but the difference from the flat fields was remarkable!!

 

754784474_20201120PerseusDoubleClusterwithHeartandSoulNebulae(re-edit).thumb.png.9271907af771b03738865e559aeabb48.png

  • Like 3

Share this post


Link to post
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

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.