Eta Carinae - First imaging session for a while

[Outcast]

A rare clear night for Wet Season, Cairns...

Temperature was a balmy 26 Deg with 87% Humidity so... not ideal.

First time out for 2 months since having my spinal surgery... New mount, first time imaging with a Newt... didn't all go quite as planned.. Target was supposed to be Horsehead but, I had some power supply issues which, after sorting, I decided to just go with a simple approach on Eta Carinae.

Must remember to reread Intervalometer instructions... might actually have half a clue what I'm doing then...

Processed at 1:30am because I am impatient.. might have another go at processing tomorrow.. I'm not so happy with how this looks... My Subs look okay.. not great, but, okay... my processed image just looks a bit soft to me...

About 1 hr of data at ISO 800, 90 Sec Subs, unguided + 10 Darks
Canon EOS 70d
Vixen R130SF
SW AZEQ 6
DSS, Startools & Affinity Photo

Please let me know what you think & where I can/need to improve.

Thankyou for looking

[Startrek]

Carlton
That’s a great image for first time out in a while pus unguided
Nice colours too
I think you would benefit greatly in your images if you can guide
Stars are a bit fat but still round , maybe conditions , maybe a bit of fine focus needed ??
A guided star at even 60 seconds will be sharper when focused than an unguided star at 60 seconds
By the way how do you focus ?? Use Live view zoomed in on a say 2.0 mag star and take 10 or 15 sec exposures while adjusting your focus manually ??
Anyway well done !!
Glad your back on your feet again too
Cheers
Martin

[Outcast]

Thanks Martin...

Last night was supposed to be a crack at guiding, on Horsehead & Flame... but, I encountered some power supply issues, it was getting late... I went for something familiar...

For focussing, I use live view zoomed in @10x with a Bhatinov Mask, manually on a bright star somewhere near my target. Last night was Canopus... I don't take an exposure though...

Seeing was pretty crappy last night & I also think my collimation was a bit off but, after the earlier challenges.. I kinda went 'f... it' & just got on with it...

Recently purchased a Rasberry Pi & Stellarmate software; ultimately plan to get everything connected & integrated & controlled off a 10" Tablet... but, that's not as straightforward as I would have liked.. :lol:

[casstony]

There's only so much you can do in poor conditions but it's good to get out under the sky anyway.
Maybe a bit less stretching to tone the brightness down - might show more detail?

I dumped half of my subs from last night due to thin cloud and moonlight.

[Startrek]

Things can only get better from here on
Good luck and hope you some more clear nights !!

[Outcast]

Thanks Guys,

I think I'll have another go at processing later today, might dump some of the subs.. try a few different things see if I can polish the 't..d' a little more... :rofl:

But, you are right... it's good to be back in the game... even if a lot rusty...

Now comes the challenge of which toy gets an outing next & is it visual or AP... :lol: First world problems...

[LostInSp_ce]

Not bad Carlton. When do things ever go to plan with AP? I'm amazed at the amount of data you're able to capture during poor conditions in half the time that I'm able to get in good conditions. Stars look nice and round so you've got the new mount working well. Do you take flats? It can help with removing the vignetting around the edges which should even the illumination across the field. Otherwise you can try a gradient removal which might help a little.

[Outcast]

Cheers LiS,

I always seem to go 2 steps forward & about 5 back depending on what goes wrong for me on any given night... :rofl:

Thanks for you kind comments... I currently don't do flats but, know that I need to start doing so. I'm still trying to figure out the best way for me to accomplish this which for me, is a factor of ease, convenience & budget...

I've been thinking about having a crack at the cheapest & simplest option, namely, white t-shirt material & an LED torch, held in such a manner that it illuminates the material evenly... I know of a couple of others who do their flats this way I think... so, may give it a crack & see how it goes.

I still think I overstretched in my processing... been a bit busy since I captured this data & to be honest, processing is still something I am coming to grips with. Will see if I can find time to reprocess the stack & tone down the stretching a little to see if I can pull out a respectable image without the blueish tinge behind the nebulosity...

Cheers

[Outcast]

So, tonight I reprocessed the data from this image to see if I could be a little less aggressive on the stretch & perhaps get a better result...

I believe I have achieved a better result but, would be interested in hearing others thoughts with respect to this version vs the original one posted.

And yes, I cropped it a little to remove some stacking artefacts as well as some other minor issues that showed up at the edges when reprocessing.. just some odd colouration tis all... :D

Cheers

[LostInSp_ce]

That’s turned out really well. Beautiful star colour and you’ve managed to remove most of the vignetting. Well done. Unfortunately there’s not much you can do to improve the focus because of the poor conditions you had. However, for exercise purposes, something you could do to experiment with a different processing technique is to turn it into a LRGB image. Normally this done with a mono camera but for the sake of practicing the workflow you could just pretend that your DSLR is mono and treat your next imaging session as a mono run. When you get a night with better seeing take another set of subs that are as sharp as possible. Stack them and use that stack as your luminance/detail data. Since your only pretending it’s mono you can ignore the colour information in the file so no need for colour calibration or anything like that. Then combine this data set with your existing colour image for a LRGB image which should look nice and sharp.

[Outcast]

Looking at my subs, I actually think the softening of the focus of this image might have more to do with the denoising processing rather than the actual focus.

Here is one of the subs, I think you will see the focus is actually sharp... might have another crack but, be less aggressive on the denoising part of the processing.

[bgilbert]

. carlton
Nice work, sub looked good.

. The only denoising algorithm, that doesn't soften images, is stacking. Besides at ISO 800 It's unlikely that there will be any noise in the image, other than faint stars (signal). Of course if you don't like faint stars then denoise.
Giving advice on colour, or the amount of stretch, is like telling someone what football team to support.

[Outcast]

Cheers Barry,

I will give it another run & pay more attention to what is going on at each stage. I'm still fairly new to this & processing is one of the finer points I haven't quite got my head around as yet so, I kinda just follow the bouncing ball...

As to football teams; depending on the code there are only these choices...

AFL - Carlton FC
RU - Qld Reds
EPL - Liverpool
ARL - Rabbitohs (though, I'll concede I'm not really an ARL fan)...

:rofl:

[RugbyRene]

Very nice Carlton.

How’s KStars/EKOS going?

Rene

[Outcast]

Hey Rene,

Thankyou,

I haven't had a chance to play with Kstars/Ekos at all... wife has a long to do list which is keeping me somewhat occupied sadly... lol

Cheers

[RugbyRene]

Understand mate.

Rene

[LostInSp_ce]

There's nothing wrong with that sub. I can't see much noise either but if you're going to use noise reduction then maybe back off on the smoothing a little. :)

[Outcast]

:thumbsup:

[Sunfish]

Pretty good for 90 sec unguided shots. Going over to a reflector is another challenge. Guiding would be great on that focal length.

I have been using KStars and Ecos running PHD as an external guide connection lately on an old laptop and it seems to work surprisingly easily. Sharpcap seems to crash for me lately on a newer device with Win 10 so KStars is looking good.

[Outcast]

Okay... 3rd go at processing, no noise reduction this time & to my eye, it appears much sharper...

Hopefully becoming a bit more discerning in looking at what each processing step in Startools does & whether it needs undoing, tweaking, enhancing, etc...

I notice my colours change each time I process.. I need to start taking more notice of the settings I use each time so I can reproduce the colours I like... not that I don't like this one as such... but, I like the colouration more in the second iteration despite how soft the image turned out...

Thanks for everyone's time & comments..

Cheers

[mental4astro]

Of the three iterations, I'm liking the second one more than the others.

The second one is less "blocky". Stars are more pinpoint and more of them. The nebulosity is more extensive, with a greater range of tones and dynamic range. The details that can be seen are also far more extensive and easier to see. This includes the subtle nebulosity that resides between the main "petels" of the nebula complex - it is mottled, subtle and with its own structures. The third pic in particular removes so much of the subtle complex structures. It has the least amount of visual vitality.

Bring up all three pics side-by-side and toggle between them so compare their differences.

As far as colours go, this is a very personal/subjective aspect. My own colour perception is different from yours, and my monitor is different again, so I won't comment on the colours. What is "correct" is really invalid. It is all about the visual appeal.

Alex.