Part of Veil Nebula

[Pld]

I took this a few nights ago but had a delay in processing due to my calibration frames playing up and showing ampglow in the stacked image, A new set of calibration solved it. 

Stellamira 90 with reducer and Asi 294Mc Pro camera, 95 minutes of 5 minute subs.

[TiffsAndAstro]

Was this via a dual narrow band filter? If so which one?

[Pld]

Yes, it was taken with the El-Enhance filter.

[TiffsAndAstro]

7 minutes ago, Pld said:

Yes, it was taken with the El-Enhance filter.

For 90 minutes I think this is a great result. I'm new to this, but I think there might be a little still left to be stretched a bit more. Maybe, anyway.

[Vroobel]

Its a nice picture and the object is explicit. Could you try subtract a little of saturation? 

[Pld]

Thanks for the replies, 

I have been thinking that it needs tweaking in some way, I'll try reducing the saturation a bit. I find it a bit tricky as looking at this now on my tablet, it's quite darker than on my PC, which is where I do the processing. I guess that different screens and lighting conditions have an affect.

[Pld]

I've reduced the stauration a little, which has made a difference (I think) but then again my wife doesn't allow me anywhere near colours. 

[Pld]

I think this is probably a bit better.

[Elp]

1 hour ago, Pld said:

I guess that different screens and lighting conditions have an affect.

This makes a massive difference. If you're really into it you should calibrate your monitor with a calibration camera, but the value in doing this depends on whether you use the monitor for such accurate purposes in the first place (print, media work), and whether the monitor is hardware capable of displaying a wide colour gamut in a range of colour spaces. The tech of the monitor makes a difference, as I use OLED I find this sufficient to display colour and contrast as I want it, I could calibrate it but haven't currently seen a need to, I also usually process images in the dark with no room lighting, this has a profound effect on the end result you produce. Then check on a number of display devices to make sure it's not over or undercooked.

[Vroobel]

13 minutes ago, Elp said:

... I also usually process images in the dark with no room lighting, this has a profound effect on the end result you produce ....

 

This is crucial at least at work on gradients. My small 27" (  ) display is located perpendicularly to windows, so I close blinds during a day, but I also prefer post-processing at night. BTW, working with glossy displays must be a nightmare, so matte displays are another key factor. 

 

[Vroobel]

I just reworked my Cygnus Loop captured using a nearly twice smaller refractor (2" Askar FMA230) and also a dual-narrowband filter. That's right that I used an astro-kamera while you used the Canon DSLR, but your 90mm glass gives a much higher optical resolution of the image. My conclusion is that thanks to a gentle stretching you can save a lot of faint details. The picture below shows roughly the same area.

Moreover, I would double the total integration time during following nights to get a better signal-to-noise ratio.

I guess you used a diagonal or prism, am I right?  Your Witch's Broom is 'horizontally' mirrored.  

 

 

 

 

Edited June 29 by Vroobel

[Pld]

Hello Vroobel

Thanks for this reply, the image is excellent, I like the colours and resolution. How was it processed? I'm currently finding my way around Siril, but only using a fraction of the functions, although I'm improving.

I was using an Asi294 mc pro camera, and have noticed before that images seem to be reversed, I'll look out for that and correct them in the future as necessary.

[Vroobel]

Oh, sorry, I don't know where I found the Canon... 🤭

I'm not quite sure, but I think you have a higher resolution even if your camera has slightly bigger pixel than my one. 

I think my details look better because of the BlurXterminator, it corrects stars shape and also improves the details of nebulosity thanks to deconvolution based on AI. 

I can do it for you if you share your raw stack file. I'm really curious about the result. 🙂

[Pld]

Thanks for the offer, but I have to ask which is the best way to share the file?

[Vroobel]

If I'm not wrong, it's enough to attach it here as a TIFF file. You can also upload it to any cloud storage you use with granting it permission to any person who has the link, then you should paste the link here.

 

[Pld]

Light_Stack_144.fit

Hello Vroobel

Apologies for the delay, I've been busy on two or three fronts over the last few days.

I've attached the stacked file (I hope it worked) if you would like to have a look into it.

Regards

Peter

[Vroobel]

You gathered quite nice data. I performed a Spectrofotometric Colour Calibration, applied the BlurXterminator, removed an easy gradient, separated stars and the nebulosity and returned them as linear images (attached), so you can play with them. The image below results from 10 minutes of work in PixInsight without too much care. You have decent stars shape across the whole frame, so the BlurX didn't do too much there, but it improved details of the nebulosity. I used an 85% correction.

I suggest collecting 15-20h in total (which improves an SNR and the details even more) plus stars separately, e.g. 30 x 30s each sub with ALP filter or without the filter at all, but your stars aren't greenish, so it's not a must.

Good luck!  

 

 

 

Light_Stack_144_Starless_Linear.tif Light_Stack_144_Stars_Linear.tif

Edited July 1 by Vroobel

[Pld]

Thanks very much, I appreciate your assistance with this. If the clouds allow I'll collect more data as suggested. 

Peter

[Vroobel]

I'm really curious about the result. 🙂