Bubble Nebula - NGC7635

[Selborne]

Hi Guys,

I thought I would share with you the spoils of last nights observing, it was a very clear and calm night here in Suffolk and I took the opportunity to travel a few miles out from Stowmarket, to and old second world war airfield, were there is next to no light pollution, as a result I thought I would try to capture the Bubble Nebula. 

This Deep Sky Object has always been a difficult one for me, never really managed to pull it off, however with the aid of my Skywatcher 100 ED Pro Esprit Telescope complete with my Sony A7Rii Camera, atop my Skywatcher NEQ6 mount, using my Skywatcher 50ED Guide Scope, complete with Altair Astro ASI130mm (mono) guide camera and PHD2 Software of course, I was able to capture the picture below.  I have to say I am very happy.

The images is made up of 10 x 120s frames at ISO5000, no darks, flats or bias frames were used, stacked in Photoshop via the Mean function, levels and curves adjusted to suit.  The Sony A7rii camera seems to manage noise very well, even at 5000 ISO.

Welcome comments / discussion.

Many thanks

Jamie

[simmo39]

Nice bubble, A  target I aim to get soon.

[lux eterna]

Hi Jamie,

Nice to see we have a few things in common: we are both DSLR users and practice portable astro photography. You have my respect for being portable with so much equipment. I go much lighter with just a HEQ5 Pro and no pc (just a tablet and a standalone autoguider), and still it is a lot to carry.

Also, we both use PS for stacking (although I use "median" type, but after getting my hands on DSS 64 bit I think I will go that route from now on).  How do you make the alignment (or "registration") for all the subs (before stacking) ? Long ago I used "Auto-Align Layers" in PS, but it often did a bad job so I later purchased Registar for that purpose.

Also, we both skip the darks, flats and bias frames.

Anyway, you got a nice bubble, I really like the colours. I guess the A7Rii is unmodded, because with my modded dslr the red tones in the Bubble were so strong that I could not find any blue tones at all. I finally managed a little blue after a few hours of exposure with an OIII filter.

Cheers

Ragnar

 

 

[Selborne]

On 04/09/2018 at 20:12, lux eterna said:

Hi Jamie,

Nice to see we have a few things in common: we are both DSLR users and practice portable astro photography. You have my respect for being portable with so much equipment. I go much lighter with just a HEQ5 Pro and no pc (just a tablet and a standalone autoguider), and still it is a lot to carry.

Also, we both use PS for stacking (although I use "median" type, but after getting my hands on DSS 64 bit I think I will go that route from now on).  How do you make the alignment (or "registration") for all the subs (before stacking) ? Long ago I used "Auto-Align Layers" in PS, but it often did a bad job so I later purchased Registar for that purpose.

Also, we both skip the darks, flats and bias frames.

Anyway, you got a nice bubble, I really like the colours. I guess the A7Rii is unmodded, because with my modded dslr the red tones in the Bubble were so strong that I could not find any blue tones at all. I finally managed a little blue after a few hours of exposure with an OIII filter.

Cheers

Ragnar

 

 

Hi Ragnar,

thanks for your quote, 

yes it is a lot of equipment to take, I manage to get everything into 3 peli cases, so there is good protection for travelling.  I have a small Mercedes Citan Van which allows for easy travel, plus it has three leisure batteries connected together feeding an inverter, which gives silent power all night if needed, around 2.5kWh, more than enough for the scope, computer, dew heaters etc.

With regard to Photoshop, I pay monthly for the Adobe Photographer pack, Lightroon CC and Photoshop CC software, £7 per month, very good value, with the latest software you get the latest functions.  with regard to alignment, yes I just use auto align function, but it only works for the one set of subs taken at the same time, so if I do 20 shots at 2 mins in one go, they will align ok, if I move from the target and the return later, it will not align the different sets of subs.  I will try Registar as you a have done.

With regard to the Sony A7Rii, I have to say it is incredible, I used to use a Canon 60Da which was fine, but the Canon noise and colour banding was awful, as a result I struggled to go over 1600 ISO and I had to take darks, flats and bias frames to get anything useable, the Sony A7Rii has none of the noise or colour banding issues of the Canon, I can use 20000 ISO  if I wish and with 30 plus frames stack the grain away in photoshop, see the Sony makes grain not noise and there is zero colour banding, its more like a super hybrid of film.  If you note all the top range astro cameras you can purchase use the Sony chips, and I suspect this is why.  The camera, as you correctly deduced is not modded, I prefer the colour that I get, as you say the modded cameras produce to much red, but they do get more nebula showing, so it is a trade off, I prefer the colour, as you can see below from the Iris Nebulas taken last month.  The other really great thing about the Sony A7Rii is that it is 42MP, this means that I can zoom in to 1:1 pixels giving me either super wide field with my 100ED Pro Esprit F5.5 or at 1:1 I can get much closer, more like my Canon 60Da on a 150mm F7 scope.

Thanls again for the chat,

Regards

Jamie

[Selborne]

On 04/09/2018 at 11:43, simmo39 said:

Nice bubble, A  target I aim to get soon.

Lets us see the results once you captured it, would be interesting to compare you equipment set and results ? 

[Demonperformer]

Uncalibrated and ISO 5000! That is a stunning result.