Double cluster, heart and soul nebula - feedback please!

[FenlandPaul]

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

[FenlandPaul]

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.

[Seelive]

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.

 

[Nik271]

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 November 20, 2020 by Nik271
grammar

[FenlandPaul]

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.

[FenlandPaul]

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!

[FenlandPaul]

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!!

 

[Kyle Allen]

Very nice! Flats make image processing much easier. 🙂