Adam1234

Thanks Scotty.

Nothing that I believe to be out of the ordinary, just pretty much followed the tutorials described by Light Vortex Astronomy and Trapped Photons:

- calibrated, registered and stacked the individual panels for each filter (during registration stage registered the Oiii to the best Ha sub so Oiii and Ha are already aligned)

- dynamic crop to cut out the stacking artefacts (same crop applied to Ha and Oiii stack per panel)

- DBE on each stack

- build rough mosaic using star alignment (settings 2d surface splines, distortion correction and register/union-mosaic)

- register each panel to the rough mosaic (settings 2d surface splines, distortion correction, and register/match images)

- dynamic crop on the rough mosaic to remove any dark edges or uneven edges. Apply tye same crop to all registered panels

- DNAlinear fit script to match intensities

- Gradient Merge Mosaic to create the final mosaic

https://www.lightvortexastronomy.com/tutorial-preparing-a-mosaic.html

http://trappedphotons.com/blog/?p=994

I've now got pane 2 of what is to be a 4 pane mosaic of the Heart Nebula IC 1805. 

As it's moving down towards the West more each day, the current weather dictates that I'm probably not going to finish it this side of the year, so here's the progress so far.

5hrs each of Ha and Oiii. With Ha also used as luminance (HaHOO).

Exactly what Stuart said.

Dark flats make a huge difference in the effectiveness of flat frames. Make sure the same exact same settings (gain, temperature, exposure) are used for the dark flats. 

If you struggle to get dim your light source enough to get longer flats, I increase the number of layers between the source and lens (i use sheets of white paper) to control the exposure time.

Hope that helps

Cracking image

Unsure if there would be an issue stacking stacks or not. I would probably recommend just re -stacking all of the original files plus the new ones. 

If you re-use the same darks and flats across the sessions (provided the set temperature on your camera is the same across sessions and you keep tye camera attached to the scope) you can just put everything in the same group in DSS.

Just out of interest, is there any reason why you don't do your calibration/registering/stacking in PixInsight?

One thing you could do with the flats is to use image statistics in pixinsight to check that the flat is exposed well and you have not black clipped or white clipped any data (i.e. no pixels with value 0 or 1).

I've found short flats less than 1s don't work so well with my asi1600mm, they tend to overcorrect (or undercorrect, can't remember which)

I get longer flats by increasing the number of layers between the light source and the scope if I can't dim the light source enough. I use a similar method to the t-shirt method, but I use sheets of white paper instead, reduces the risk of creases and loose fibres falling onto the lens.

My flats are generally around 5 - 7s. The advantage of longer flats is it averages out any flickering of the light source that you can't see with the eye but that can be captured using short exposures

Great image

Thanks for the comments! If I go for a third attempt (which I'm sure I will, I'll maybe go a bit easy on the ACDNR on the Ha, or skip it altogether- I had already used Mure Denoise and EZ Denoise Script and it already rather clean before I done ACDNR after stretching.

26 minutes ago, geeklee said:

It looks great at full resolution and should make a cracking final mosaic in 2030 when you get the skies 😉 😅   

🤣🤣🤣🤣

27 minutes ago, geeklee said:

Super image again Adam.  I prefer the added touch of stronger OIII but the Noise Reduction (NR) reduction looks a little stronger here - personal preference of course, but I thought the NR in the first, with a little grain, was fine.  Maybe somewhere in between on NR?

It looks great at full resolution and should make a cracking final mosaic in 2030 when you get the skies 😉 😅   One thing to keep an eye on is some of the brighter stars, they have some small artefacts around them, perhaps from Starnet?

Yeah they are from starnet, from the Oiii data. The Ha starless was really clean, no artefacts at all. I always have trouble with halos on the Oiii filter (ZWO 7nm)

Lovely image!

Beautiful!!

Fantastic!!

Here's my second pass at processing - I think I prefer this one, what do you folks think?

I think that's incredible

Incredible images and great detail  well done!+

8 minutes ago, maw lod qan said:

Incredible!

10 hours of imaging. Did you get that 10 hours in one session or was it several nights?

I am so, befuddled would be the best way to describe my thinking when I see these massive times put in on camera time!

Thanks!! I got it over 3 nights (could have done it in 2 nights but my power tank ran out of battery on one of the nights).

20 minutes ago, scotty38 said:

Lovely image that is. Is it cropped at all as I can get much more in with my 80mm and 294? Just curious....

Thanks!

Yeah it is cropped a little - a bit more than would be desired, but not by a significant amount.

I think the sensor on the 294 is slightly larger on the long side and slightly smaller on the short side, than the 1600

My first pass at the Fish Head nebula (IC 1795), part of the much larger Heart Nebula in Cassiopeia. 

My intention is to undertake my biggest astro project so far and do a 4 pane mosaic to capture the whole of the Heart. It may take a while for me to get panes 2 - 4, so here is pane 1. 

Ha = 60 x 300s (5hr)

Oiii = 62 x 300s (5.2hr)

c&c welcome!

Thanks

Adam

Very nice

I won't make any suggestions on actual cameras as I don't have any experience with the C8 and have only used the ASI1600mm, however, as has been pointed out you want to make sure you don't choose a camera that will result in you significantly over or under sampling. 

 Astronomy tools ccd suitability calculator here https://astronomy.tools/calculators/ccd_suitability will help you determine if you will be hitting the right mark with a telescope camera combo.

Adam

Very nice for a quick and dirty process. I'm looking forward to seeing your final version!

10 minutes ago, geordie85 said:

What a fantastic image, lots of fine detail too. You should be proud of that

Thank you very much!

1 hour ago, daemon said:

Congratulations Adam!! That is stunning!

Thank you!!

WOW, excellent image

Nice capture