M78 Casper the Friendly Ghost Nebula embedded within Ghostly Ha

[@franks2725]

Amazing image. I like the version with the frequency separation. That swirl is very cool.

[@chridignan9178]

Fabulous - and so much to learn from the objects within. Thank you.

[@ajmxr9]

I like how you did it. When you present just the LRGB first it seems way less busy and lets you orient yourself first

[@gabewrsewell]

i appreciate the rundowns like these of your images, they’re very helpful. I like the full implementation of the hydrogen data, it does well to hide the bit of colour mottle we get from those very low signal areas in RGB. I had my first light finally with my own 10” iOptron newtonian, but i was dealing with some very significant collimation shift over the course of a few minutes once i set it running, i must be doing something wrong in my collimation but it’s so cold that it’s a real PITA to get the bugs worked out! I also got first light on my 75mm f/0.89 EAA rig, plenty of optical issues to be worked on there of course. I was hoping you’d show the continuum subtraction, i agree this was a really clean one too! i like the broad, feathery textured hydrogen emission that seems to be throughout the orion region.

[@setiv2]

I think it is your focus shifting rapdily. You really need to autofocus every 30min or so at first for a few hours until the whole scope is at equilibrium. Then i have it autofocus every degree change or 90min

[@gabewrsewell]

@ my focus was indeed changing a lot over the course of minutes, even though the ambient temperature was only cooling a couple of degrees per hour. but would that that affect the collimation as well? on both a star test and laser collimator, it was nice and concentric at first, then less than 10 minutes later it had drifted out of collimation again, as well as focus. I figure i wasn’t using the locking knobs at the back correctly. glad to hear the big focus shifts are corroborated though! i was saying to a friend, i see why they so readily advertise that this scope is iEAF compatible!

[@setiv2]

@gabewrsewell yes gotta adjust that often at first as the steel tube cools. I havent noticed collimation drifting much though. I check it after about a week of use and have to loosen or tighten a knob mahbe a 1/8 a turn. The laser dot back in the collimator is always back down the hole to the laser so i am tweaking getting uniform brightness on the return so it is very close still. I wonder if your focuser is shifting. Did you double chexk the tighness of the screws that hold it to the mount? I had to tighten mine.

[@gabewrsewell]

@ good point, I haven’t checked that. i’ve used it for planetary from my backyard for a couple months before this first deep space session, and it held collimation perfectly over several weeks in the garage as the temp fluctuated. yet the road out to my dark site was quite bumpy, so i don’t doubt that could’ve loosened the focuser. also my initial flats were pretty bad at correcting, it was just with the white t-shirt method, but i prefer sky flats ideally. is that what you use with this scope?

[@setiv2]

@gabewrsewell sky flats yep. I used to use a lighrscribe pad but that was too small for this scope and switched to sky flats. I have no idea why i wasnt doing this earlier, so mich simpler.

[@Aerostar509]

Boy, you sure have had some good weather to get all that data.

[@setiv2]

Weeks to get it all. You see how infrequent thwse kinds of videos are from me. I make a video for every image of mine and i dont have too many videos on actual targets

[@AntonioPena1]

Great way to close the year, this shows your great job, and infer what is your scope mm size, I love the option 2 more, contraste great with the HA Red, also love the HA Arrow region, good job!

[@AstroCapture325]

Very nice as always. I prefer the RGB as the main image. I know you tried a bunch of permutations, did you look at dialing back the Ha when you performed image blend?

[@setiv2]

Yep. You can see the one with the frequency seperated ha is just a touch of ha throughout.

[@dougiesmart1623]

Nice M78 👌👌

[@haiderbhogadia4829]

Amazing wow!

[@j.s.3407]

Can you elaborate on your "masked screen" process you used to add Ha to your LRGB? Seems like something very useful.

[@setiv2]

I will have to make a video on that. Essentialy i used a range selection mask to protect the dark dust lanes then screened the ha to it with the mask on. Wanted to help retain the dark nebula without washing it comoletelt over with Ha signal

[@meibergstrmandersen9181]

Thank you Frank, a lot of learning to pick-up for a novice like me. ✌ And nice to see the Ha trick on Astrobin. Which Bortle level are you shooting at with the 10" iOptron ?

[@setiv2]

Everyone asks bortle level. Decent suburban skies. Like a 6.5. I have never measured pr anything though. It honestly was never a th8ng that was important to me really

[@meibergstrmandersen9181]

@@setiv2 That is good news and a good learning. It's one of those things that all say. I checked in with Jim Thompson, who does a lot of analysis of filters and performance under various bortle conditions, and I am in bortle 4 to 5. I am inclined to conclude to just make sure to capture data when the chance is there, rather in speculating in sending gear to remote observatories. (which i probably can't utilise fully anyhow, due to own time constraints.)

[@setiv2]

@meibergstrmandersen9181 i am a 100% backyard imager. Nothing remote here

[@SDOC-xp5od]

You mention trying a frequency separation technique before blending the images, is this using either HDRMT, or Multi-scale linear transform? I know you've done tutorials before, but a brief workflow tutorial for this challenging image would be great!

[@setiv2]

I used affinity photo to do the seperation then imported it back into PI. You can do it in PI but it is soooo convoluted with MMT

[@KJRitch]

Another Wow! How many nights did it take to obtain 36 hours of data? You must have had a run of clear nights? Do you use dark flats vs bias frames for calibration? What is the exposure of your flats with the 294 camera? How many 15 minute exposure did you have to throw out due to guiding error? When using mono LRGB, is luminance always shot with longer exposures vs the color filters? Do you have to worry about salt in the air at your location? I only have a OSC camera. Would I need a duo band filter to get some decent results? It would be interesting to see how you would process this data in something like Siril. Thanks.

[@setiv2]

Woah that is a lot of questions!! LOL. 1 clear night of data is about 8hrs of exposure. So a number of nights. I have it all listed on astrobin. I use Darks, Bias, Flats for calibration. I do sky flats so my exposure on the 294mm is very short. on the order of 15ms. The 294mm is a different sensor than the 294mc which you can't do short exposures like that. Almost 0 lost do to guiding errors. Other factors sure, but not guiding. Luminance is almost always shot with shorter sub exposures but more of them. Luminance is where you get the most detail so you want to get as much of that as you can. No salt in my air. Your UV/IR cut filter will do perfect for the broadband items. duo or dedicated ha if you want to capture the ha like i did. I have yet to do a Siril processing video, but I have other tutorials showing my seti astro tools

[@kevinivey8422]

I do have a suggestion. As you noted, you were having some struggles with blending your images in a satisfactory way. I would suggest, and I think it would also be an interesting video if you collaborated with Craig over at Utah Desert Observatory. I know that he likes and watches your work. He very well may be happy to assist.

[@setiv2]

I did see he just shot this target as well.

[@goldfish31ful]

What scope did you use for this? Nevermind, I saw on your astrobin page.

[@SvbonyOfficial]

So can we see Ultraman there? 😆

[@jesuschrist2284]

Looks like a quasar and jet. Im sure its not though :(