18 hour Crescent nebula

[crystal otter]

Knock yourselves out! theres 3 files, 1x drizzled stack, 2x drizzled stack, RGB star stack

https://drive.google.com/drive/folders/1bLjDdqzM530aB69AkcirHVJ5qVaMAkbB?usp=sharing

@upper sequoia here you go

[upper sequoia]

Oooo

Gracias

[crystal otter]

Ningún problema, signed. Google translate

[astral dune]

might give this a shot

what filters and camara?

[crystal otter]

Optolong Lenhance, ZWO UV/IR cut, ASI 294MC pro, should be platesolved already

[upper sequoia]

Pix and PS of course, nice data honestly.

[astral dune]

oops (he forgor)

[novel karma]

ratbag gettingt too op

[astral dune]

giving this a run now

how do yall make it so purple

pink

bc this is mine after star removal

also youve got amp glow on the bottom left

[fluid sage]

nicee

[astral dune]

tell me the way

[fluid sage]

DBE on this is sacrilege

[astral dune]

yea it doesnt do anything

also i did mine HOO pallete...

unless you guys did HHO

[fluid sage]

-align the rgb,hoo stacks
-SPCC both
-blurx, dsnr and starnet
-split the channels into Ha, O1, O2
-combine O1 and O2, i find a 1:5 ratio of the blue channel and green channel gives the cleanest Oiii image
-combine into a HOO, then curves (mainly blue S curve, also brought down green to make it less green)
-HT the RGB stars, saturation curves, SCNR green, then magenta at 40%
-combine then slight tweaks in Ps

[fluid sage]

everyone does HOO for this

anyone with any sense at least

anything else looks weird asf for 2 channels

and is just wrong lol

[astral dune]

deepsnr on HOO? doesnt it need 3 colour channels to work

[fluid sage]

it does have 3 colour channels

this is an OSC image

so it always has 3 distinct channels

R,G,B

[astral dune]

sorry, 3 noise profiles

[astral dune]

also what do you mean "allign the rgb and hoo stacks?"

[fluid sage]

star alignment

so like matching their framing

[astral dune]

right

are there youtube tutorials on how to do these processes?

so for SPCC on the HOO image, what do i do for the green filter?

like this?

@fluid sage

[fluid sage]

no its just practice makes perfect and getting critiqued by people on your processes

[fluid sage]

yeah thats right

[astral dune]

right...

[astral dune]

also what do you mean by o1 and o2?

and where should i extract ha from

[fluid sage]

oh thats just what i named the G and B channels, because they basically represent the Oiii signal with varying amounts of noise

[fluid sage]

R channel

[astral dune]

also im asking a lot of questions bc i dont know what im doing lol

[fluid sage]

yeah thats all good, i dont mind helping out at all

so in the dual narrowband images, R represents Ha, G represents Oiii, and B also represents Oiii

[astral dune]

how do i combine the g and b?

[fluid sage]

so if you do a channelextraction on the RGB image (taken through a dual narrowband filter) then you are left with 1 Ha image and 2 Oiii images

[fluid sage]

i just did (O1+O2*0.2)/1.2

because the O2 (blue channel) is weaker, i weigh the image by less (the coefficent 0.2), so it contributes to the signal without contributing excessively to the noise

its a balance

theres a formula to estimate SNR, but i used it and it didnt work

usually it works just fine, but not for this image idk why

[astral dune]

the guy that made astrosharp made a calculator

[fluid sage]

isnt that an SNR estimate for before you take your images?

[astral dune]

proll

[fluid sage]

so you know how many subs it takes?

[astral dune]

oops

[fluid sage]

yeah dont use global context

do the triangle or square

just make sure its on "create new image"

[astral dune]

yea i clicked the square and didnt do anything

oh

[fluid sage]

or it will replace an existing image

[astral dune]

ok got it

so now i use the GB to combine with the greyscale Red (ha)?

how do i do thaat

same formula?

man narrowband processing is so complex

this is why i stick to broadband

[fluid sage]

once u got the Oiii channel

do ChannelCombination

Ha in red

Oiii in g and b

[astral dune]

Alright

Gimme a bit. Eating dinner

[astral dune]

is this meant to be it?

that doesnt look right

[astral dune]

im prolly asking for a lot - it would be more helpful if you could give give more detail what youre doing in this

[fluid sage]

yeah thats it

[fluid sage]

whoch part specifically? thats the whole workflow

[astral dune]

like go more indepth in the processes

[fluid sage]

maybe tmrw i cant type it all out on my phone

[astral dune]

no worries

i closed pix anyways

[upper sequoia]

I usually did this for OSC duoband data but in this instance it really didn't seem to make a difference worth while.

[upper sequoia]

Careful DBE is necessary as that patch of oiii right beside the crescent isn't accurate. Checked my crescent data to confirm.

Still showed up on mine a bit but it was suppressed a tad.

[crystal otter]

Ahh, ngl didnt know that could be there, literally my house coords too, how to remove? (files arent in the folder until theyve been removed)

[upper sequoia]

💀

[crystal otter]

[crystal otter]

Also should say, nice processes guys! loving it!

[crystal otter]

Nah aint amp glow, theres a bright star there just out of frame, does look similar to amp glow tho

[obtuse quiver]

wait does the 1:5 thing work as good as the statistics function method u gave me

[fluid sage]

fair, but who i was replying to put reference points all over the HA

[upper sequoia]

Oof

[fluid sage]

im pretty sure metadata can be deleted manually in the fits header

[fluid sage]

the statistics are better, but you should run it on a starless so the stars dont affect stdev too much, so i just did it by eye this time

1:5 seems to work for this cam+filter combination

[obtuse quiver]

wait so I should do statistics method without stars?

bruh I did it iwth stars

[fluid sage]

yeah, problem is you have to run DSNR before starnet, and after DSNR statistic doesnt work (no noise for the standard deviation evaluation)

so you gotta run starnet twice basically

which is annoying

[obtuse quiver]

that sounds stupid

[crystal otter]

Tbh i run starnet twice when using DSNR anyway, DeepSNR i find always adds some hallucination stars, even if its only a few, id rather not have them in my image so i use the starmask that was made before DSNR

[strange stratus]

😕

[crystal otter]

Sorry! i accidently left some stuff in the FITS header, so people could easily find my address from it ill let you know when ive sorted it

[obtuse quiver]

I should probably try that too

I see some fake stars sometimes too

[strange stratus]

Thank you Ratbag152

[upper sequoia]

@desert yarrow @crystal otter wait this is the final data right?

[crystal otter]

Yeah

[strange stratus]

Did you solved the address problem? The folder is still empty 😕

[crystal otter]

Sorry man I haven’t, I’ve just gone away on holiday so won’t be for atleast 6 days

[upper sequoia]

oh dam, looks like I dont have the stacks anymore.

[astral dune]

you forgor 💀

[strange stratus]

Understood.. happy holiday
Just don't forget about me 😉

[crystal otter]

Thank you! I promise I won’t (:

[crystal otter]

You guys will get the stack today

[crystal otter]

@strange stratus @desert yarrow the 2x drizzle and star image are in there, im not sure where the 1x drizzled image has gone but if you need it i can restack it back

[strange stratus]

You don't have them in .xisf format, right? Fits would work also..

[desert yarrow]

Nice.

[desert yarrow]

made 2 versions so far. not really happy with them. having another crack from scratch

i think my background extraction killed it

[crystal otter]

Yeah but those files contain my home lat and long and i can’t figure out how to remove them from the fits header, so it was easier to convert to tif

[strange stratus]

Oh but that’s easy.. if that’s the problem. You open them with PixInsight, and then go to file-fits header. In the fits header you can edit and change the values which one of them is the location.. just leave it clean. This is what I do.
Just don’t forget to apply the changes.
I was asking because you loose a lot of file info when you do the change to tiff from a .xisf or a .fit.. but it’s ok. I’ll manage with those.. thank you for all 😉😉

[crystal otter]

Yeah sadly even when pressing "apply" it would not remove the location regardless, so it was just easier to go to a TIF file, ive checked the tif no data is lost besides astrometric data, all signal is the same and processing will be no different i can assure you (:

[crystal otter]

This ended up being my final, very pleased with the result

[novel karma]

Absolutely brilliant.

[woven birch]

Amazing Data and my first good try with splitting the image in HA and OIII feedback / tipps pls