Question Mark Nebula in SHO with my tiny 40mm refractor!

[Adam J]

Firstly thanks for taking a look!

I don’t have much time to image these days due to real life commitments and it’s been quite a while since I have done a longer integration as opposed to just pottering around. So I figured it was about time that I posted something in the DSO imaging section.

Original:

New V2:

Looking through Astrobin content the question mark nebula as a whole is not one of the most imaged targets, most people focusing on the bright core as opposed to the whole object. This is most likely due to the short focal lengths required for all but the largest sensors normally meaning a lens as opposed to a telescope. This was shot at only 180mm with an Askar FMA180 40mm triplet refractor (the original version not the V2). I am a big fan of this little scope, its good for LRGB imaging but produces especially sharp images for its image scale in SHO. Also F4.5 is fast for a refractor and fast enough for me.

I have tried to control the pallet in such a way as to show the three separate channels as three dominant colours within the final processed image as opposed to pushing it towards a duel gold and blue that most seem to favour in SHO. I have said it before but I am a big believer in three filters = three colours, or why did you bother shooting SII.

One of the things I like about this little scope is just how nice and flat the field is to the corners of my ASI1600MM Pro sensor making for an idea portable / grab and go imaging setup. That’s something that is important to me these days as since I moved house and lost the observatory in the process I have not had time to setup my Esprit 100 and heavy AZEQ6 GTI, this rig being much more practical in my current situation, I can pick it up in one hand. 

This is also the first completed image that I have shot using my StarAdventurer GTI that I got back in August 2022. The biggest advantage over my previous AZ GTI setup being the ability to dither the mount without causing issues due to excessive backlash. This is ideal for a light weight travel setup and makes for a system that can just consistently produce excellent quality subs all night long without much supervision once properly setup.

This image consists of a total integration of 29 hours pretty evenly spread across each of my 5nm Astrodon SHO filters in 300second subs at gain 200 offset 50. Calibrated by Darks, Flats and Dark Flats.

Stars have been removed using Starnet V2 and reintroduced in a HOO pallet to approximate RGB coloration. Care has to be taken with this process as Starnet is given to taking some of the brighter or rounder nebula elements along with the stars and so these have to be reintegrated selectively with each SHO channel to prevent details from being lost. This is especially true of the very small and very round planetary nebula PK119+6.1 that is absent from virtually all images of this target that I have seen recently, most likely as people are inadvertently letting their star removal software of choice cut it away during processing.

I am also pretty happy with the amount of detail that I got in some of the smaller objects present within the feild especially the Little Rosetta and so have provided some focused crops below to show them off.

Some I think might say that I could have reduced the stars further (and I could have done) but I am of the thinking that stars should not be processed totally out of images as they tell their own little story, in this case the presence of two open clusters one primarily of blue stars and one dominated by older red giant stars. I also enjoy how the star density increases down towards the bottom of the image.

Stacking took place in APP, Star removal in Starnet++ v2, processing in Photoshop CS2, Noise reduction in Topaz Labs DeNoise AI (with the lightest touch possible using the Low Light Algorithm). This is the first imagin to incorporate a few new processing techniques I have been thinking about for a while. Hopefully not pushed it too far.

Image is at about 4 arc seconds per pixel with a FWHM of 1.4 pixels and I think it stands up quite well to actual size / full resolution viewing, something that is always a goal for me in my imaging.

Below: NGC7822

Below: PK119+6.1, easily removed by Starnet++ v2 or Star Exterminator.

Below: SH2-170, the little rosetta, and planetary nebula PK118+2.1, also easily removed by Starnet++ v2 or Star Exterminator.

Below: Open cluser NGC7762.

Below: Can't find a designation for this but would have thought it warrents one, any help?

Hope you enjoy and once again thanks for looking. All feedback welcome.

 

Adam J

 

P.s With luck my next significant image will be less than 12 months away this time and taken from the top of Mt Teide using the same setup. 

Edited March 2, 2023 by Adam J

[PadrePeace]

This is a truely amazing image and easily the best one I have seen of this target by some measure.  It is especially impressive because of the skill you have shown getting this quality out of a sub £350 scope. I recall the work you did with your SW 130 PDS on the Heart nebula which was equally breathtaking. 
 

This just goes to show that you don’t need to spend a fortune to get top drawer images. 
 

Thanks for sharing AdamJ. Something to aspire toward ……
 

 

[GalaxyGael]

Lovely image and fully agree that keeping the stars is both nicer and adds to the image. I'm biased in that I like the stars as much or more than nebulosity.

And great to see the higher end of the sampling range again. with tiny apertures, large fields etc. 4"/px in this image leaves nothing at home. I recently picked up an askar fra300 (60 mm, f/5), which is a delightful dinky scope and very well built. I use a smallish Atik 460ex sensor at the moment, at 3.1"/px and also find it great. there is a lovely 'sheen' for these sampling scales with long integration.

Processing is very nice too, thanks for sharing.

[Adam J]

8 hours ago, GalaxyGael said:

Lovely image and fully agree that keeping the stars is both nicer and adds to the image. I'm biased in that I like the stars as much or more than nebulosity.

And great to see the higher end of the sampling range again. with tiny apertures, large fields etc. 4"/px in this image leaves nothing at home. I recently picked up an askar fra300 (60 mm, f/5), which is a delightful dinky scope and very well built. I use a smallish Atik 460ex sensor at the moment, at 3.1"/px and also find it great. there is a lovely 'sheen' for these sampling scales with long integration.

Processing is very nice too, thanks for sharing.

The FRA300 looks like a great little scope, there is allot of miss information about in respect to optimal sampling and pixel scale, my own thinking is the the optimal in the UK is between 2 and 3 arc seconds per pixel for mono cameras. If I wanted something between the FMA180 and the Esprit 100 then I think I would go with the FRA300 although I am cautious of flat feild astrographs at the cheaper end of the market. Wil be inteterested to see how it performs for you.

Adam

[GalaxyGael]

So far it has been good, aside from my hiccup in the first few images where I rotated framing about 70 Deg after calibrating the OAG. Very tight stars on the 3.76um asi2600mc and fully aps-c flat. I don't have any bigger chips to test. Works just lovely also with the 460ex.

I'll put up some subs here when I get a chance. With the astroxap dewshield made for the meade etx 80 , I get rid of spurious light and haven't needed a dew band yet. The astroxap flocking nucleates any dew, lens is bone dry.

It's spots are better than the rest of the fra line, seems to behave as designed when I separate out r, g and b channels from OSC subs 

Edited February 27, 2023 by GalaxyGael
Typo

[GalaxyGael]

Here is a 5 min sub using the ATIK 460ex OSC (GRBG pattern). I put this camera directly on the scope without testing for any tilt, so I think there is a small bit across the frame here. Mind you, the atik chip is nearly perfectly square compared to any ZWO camera I have had.

Its a png file saved from fits viewer no calibration, don't have siril or other at work to separate out the RGB channels. I'll have a look for other subs when I get home on the atik and the 2600MC. This is M106 at 3.1 "/px, 60 mm aperture etc.

[Adam J]

12 hours ago, GalaxyGael said:

Here is a 5 min sub using the ATIK 460ex OSC (GRBG pattern). I put this camera directly on the scope without testing for any tilt, so I think there is a small bit across the frame here. Mind you, the atik chip is nearly perfectly square compared to any ZWO camera I have had.

Its a png file saved from fits viewer no calibration, don't have siril or other at work to separate out the RGB channels. I'll have a look for other subs when I get home on the atik and the 2600MC. This is M106 at 3.1 "/px, 60 mm aperture etc.

flatness and colour correction look ok for the size of the sensor at least. Would be nice to see it on a larger sensor camera.

[GalaxyGael]

Here is a 120s sub of the lawnmower regions with my asi2600MC. Bear in mind this sensor has a lot of tilt, which I nearly have ironed out (there a 1 mm air gap now between the tilt plate and the camera body such was the poor assembly).

Calibrated with bias and flats, no other processing, saved as png from fitsviewer.

ASTAP tilt assessment of the same frame also.

 

[TakMan]

I left a simple 'like' yesterday Adam when phone browsing...
Made a mental note to return this evening to look again on the proper screen.
Your result deserved the 'effort' of using the keyboard !

Love the colour palette and detail - especially the dark dusty wisps that dissect the main nebulosity.... and you nailed the composition.

On 27/02/2023 at 00:09, Adam J said:

Hopefully not pushed it too far

Definitely not!

Would hang that on my wall quite happily !

Damian

[Adam J]

New revision pushed a little harder, again maybe too far. The main aim here to be to bring out more of the background nebulocity.

Adam

Edited March 2, 2023 by Adam J

[Adam J]

Part of this hobby is knowing when to stop processing.....but what the heck one last intense processing focusing on the core and some fun with colour!

[MartinB]

The first image is just fine!  Actually it is peachy perfect.