ngc 6992

[alacant]

Hi everyone

My gf labelled this 'El Dinosaurio' (The Dinosaur) and brought along the evidence to prove it. 6992 will never be the same again.

Our first proper outing with EKOS' new multistar guiding which despite the heat shimmer and haze, has consistently knocked our fwhm down below 3. The only algorithm I've tried which challenges the seeing on its own terms:)

Pity about the colour. My better half, who advises upon such matters, was tied up in the Jurassic era at the time m'lud.

 

Thanks for looking and of course comments -colour or otherwise- most welcome. Especially if you had a go at this recently.

700d @ ISO800 2 hours @ ISO800

Edited July 20, 2020 by alacant

[MarkAR]

Very nice, I'll have to check out this multi-star guiding.

[alacant]

22 minutes ago, MarkAR said:

check out this multi-star guiding.

Hi and thanks for your comment.

It would be great if you could. The more real world testers, the better:

This repo:

git://invent.kde.org/murveit/kstars.git

this branch:

git checkout guider-fix2

Cheers

 

[ollypenrice]

Multi star guiding is a pretty obscure topic for the beginners' forum. I think it might be time to move on, no?  I've never heard of this system and I'm naturally interested. Very obviously the image is extremely well captured and guided with tight stars right across the field. Great stuff. Regarding the Veil itself, I think the stars show that you are capturing all three colours but that blue is under-represented, though certainly not absent. There is strong blue signal from the outer parts of the 'Network Nebula' so it might be worth working out how to capture them. Are they falling foul of an LP filter? I've no idea.

Olly

[wimvb]

Great to hear that ekos uses multi star guiding. I learned about this a few months ago, when Tommy Nawratil used it with his next generation Lacerta Mgen guider.

Time to update my indi/ ekos system. Do you know if phd has something like this in the works?

Btw, nice ngc6992, but the dinosaur should be a velociraptor. 😉

[alacant]

14 minutes ago, wimvb said:

the dinosaur should be a velociraptor.

Excellent. Veliciraptor Nebula it is then.

14 minutes ago, wimvb said:

phd has something like this in the works?

There was a discussion some time ago but at the time I think the coding was in its infancy. Had a quick search on the PHD2 forum but it's getting close to astro dark here...

Cheers and clear skies.

[alacant]

1 hour ago, ollypenrice said:

blue

Yeah. Blue stars. I just can't get them. Almost certainly my eyes. And process.

No filters and the only glass is a cc. Still thinking...

1 hour ago, ollypenrice said:

Multi star guiding is a pretty obscure topic for the beginners' forum

OTC. It's a simple and effective option by which to guide. We need all the help we can get, especially when setting up guiding.

Modern software helps take the pain out of astrophotography. Especially for the beginner.

Cheers

Edited July 20, 2020 by alacant

[alacant]

Here is the multistar option in action in EKOS. Simple to setup, easy to use and well worth a go.

Just started The Cat's Eye Nebula.

Wish us luck:)

 

 

[ollypenrice]

41 minutes ago, alacant said:

Yeah. Blue stars. I just can't get them. Almost certainly my eyes. And process.

 

It's not just the blue stars, there's blue nebulosity missing as well. It may be to do with your colour balancing routine. What do you use? It's possible to manipulate the blue channel independently but I never find managing colour channels manually at all easy and try to avoid it. (Or could it be your white balance causing the offset away from blue?) I used to find your reds rather yellow and your blues rather cyan but, if anything, I think your Veil is a tad the other way. It's still very good but we all want that last drop!

Olly

[wimvb]

I've been reading up (aka googling) on multi star guiding, and it seems that Maxim used it in 2015 already. Back then, PHD2 developers were also looking into it. There seems to be uncertainty whether it is better than single star guiding. My guess is that if guiding is stable and not too much influenced by seeing, then naturally multi star guiding would give the same results as traditional single star guiding. But I have found that my guiding depends a lot on seeing, even if I use 3 - 4 seconds guide exposures, and I will definitely try it next season (astro darkness is still a month away up here).

[alacant]

11 hours ago, wimvb said:

seems to be uncertainty whether it is better than single star guiding

Hi

I'm sure the reading is interesting but for us at least the best way to remove any uncertainty was to get involved.

In our experience and by comparison, it has improved guiding over single star in PHD2. That's not the oft ill quoted RMS figures, but rather the fwhm of the stars.

Perhaps best to lose the theory and just do it though. No guarantees though. Just fun!

Oh, and remember that it's not just SEP multistar which is now available in EKOS. There's the new GPG guiding and reusable calibration. 

11 hours ago, wimvb said:

I will definitely try it next season

That's great news. Do report your findings.

 

Cheers everyone, clear skies and stay safe.

 

 

Edited July 21, 2020 by alacant
terrible english

[alacant]

12 hours ago, ollypenrice said:

blue nebulosity

Hi

IIRC this was DarkTable cmyk after StarTools had done the heavy lifting. In fact, I can't remember setting the camera profile. That could be it.

I'll certainly take a look at the blue channel, but I think a lot of our colour -or lack of- issues are due to length of exposure. Puede que is all that is expected of a dslr over 2 hours. Especially with the sensor well over 30º and still 25º ambient at dawn.

Cheers and stay safe. 😷