First light with EdgeHD 8" - NGC2359 Thor's Helmet

[Doogs38 (Alex)]

Sharing for fun. Nothing like diving in at the deep end with a new imaging scope (SCT), new focuser (EAF), new imaging solution (ASIAIR Plus) and new guiding method (OAG). Except for the mount, the whole rig was new and very different to the 120ED/Stellarmate combo I've been using this year (and will keep using). It took me hours to just achieve PA and obtain a couple satisfactory subs, which actually weren't all that satisfactory I learnt that imaging at f/10 is painful and while guiding was (eventually) satisfactory at ~0.5rms or less, the SCT's long focal length and ASI294's pixel size meant that guiding had to be excellent else stars weren't round. I ended up deleting half the subs as most stars were cr@p but I kinda expected that. I will get a 0.7 reducer immediately! Very grateful that I learnt the basics with a refractor/Stellarmate and could solve camera/mount/guiding/network problems as they arose.

This was another good opportunity to play in PI - it’s awesome As a ‘before and after’, I've attached the linear stacked image (from APP), and the final image produced in PI where I put lots of lipstick on my pig ... did I mention that PI is awesome Alex

EdgeHD 8"
46 x 240s (~3hrs) UV/IR, ASI294MC
Darks, flats, dark flats. PI and PS.

[evltoy (Wayne)]

Very impressive. Top job on 90% new rig.

I’ll be watching out in the future as your setup is pretty much the same as mine

[oska (John)]

Tremendous! Congratulations on a fantastic result. yeah 2000mm is another level fun

[AstroViking (Steve)]

With fantastic images like that, watch out that the moderators don't kick you out into the "grown-ups" room!

[Doogs38 (Alex)]

Thanks Wayne , John and Steve.

John, I’m developing a very healthy respect for folk imaging at long focal lengths I’ve had the SCT out for three nights and jeeeez it’s been a painful experience trying to image at f/10. My resultant, heavily edited images are more an expose of PI’s remarkable capabilities than the quality of raw images out of my camera. I’m impressed the ASIAIR can routinely get my mount tracking at around 0.4-0.6rms (better than Stellarmate/Ekos). But at f/10, even that kind of guiding isn’t sufficient for sharp images out of the camera - the stars are messy. Hence I’ve already ordered the Celestron 0.7 reducer … should be here this week … and typically, won’t be a clear night until 2 Jan.

Steve, not a chance

[oska (John)]

I vaguely remember a post from someone else on the same topic ending roughly: "...and after that rollercoaster ride I gave my old trusty refractor a warm hug on my way to bed". Oh man...

[Dilsh]

Hey Akex,

Feeling your pain.

I just purchased a C925 edge HD i tried to Thors Helmet as well.

The seeing was average but that resulted in subs that were unusable, something that rarely happened with my ED80.

Awesome pic. You should be very happy with that.

Dilshan

[Dave882 (David)]

Excellent image. That’s fantastic quality and processing is great. I reckon your stars look pretty good, so looks like your already got the rig going ok. ASIAIR PA routine I’ve found to be very very good so if that’s taking you a long time (hours) to nail then feel free to reach out for some help. Good balance, a PEC routine and playing with your guide stetting may help reduce some of those dud subs. If you’re dithering (recommended) with extra weight / FL make sure you give your mount enough settle time

I’m planning to have a shot at PI at sometime this year but just building up the courage. Your posts (and a few others) are giving me some serious encouragement to take up the challenge!

[Doogs38 (Alex)]

Abso_freaking_lutely

Originally Posted by oska

I vaguely remember a post from someone else on the same topic ending roughly: "...and after that rollercoaster ride I gave my old trusty refractor a warm hug on my way to bed". Oh man...

[Doogs38 (Alex)]

Thanks Dilshan … I reckon we can only get better from here, or so the theory goes I got the 0.7 focal reducer this week but haven’t had an opportunity to use it … dam La Niña grrrrr My SCT also needs collimation so that’s my next learning experience … using tri-Bahtinov mask to achieve good collimation. The combo of collimation and the reducer should help improve my images. Just … need … the … clouds … to … go … away …

Thanks Dave, and thanks for the advice too. I think I’ve now got the AA+ PA sorted. It was just new, very fussy when close to PA and gave a slightly different result to my Polemaster, more so than the difference between KStars/Ekos and my Polemaster. That said, the AA+ is doing something right as I had best guiding ever (mount = AZ-EQ6) after some tweaking of guide settings combined with a settled atmosphere. I’m using the same balancing method I’ve been using for my refrac; RA is slightly east-side heavy and DEC is slightly camera heavy. I’ve recently tried a few meridian flips without adjusting the balance and both Ekos and AA+ seem to have managed BUT guiding was worse after the flip. How do you manage (re)balancing after the flip? Pause the shoot and tweak balance?

I’m keen to know more about what you do for a ‘PEC routine ‘. Do you use PPEC and AA+ together? Something else? I haven’t trained my mount ... is it worth doing? A lot (but not all) of the advice in various forums suggest that using PPEC and auto-guiding together will produce erratic guiding as the inherent nature of what they do means they’ll clash. Sooooo I’ve not done anything with (P)PEC other than using the PEC settings in Ekos (which produces an excellent result). I couldn’t find similar settings in the AA+.

Btw, PI is awesome and I recommend downloading a trial version and having a go. It *will* do your head in until you’ve run through it a number of times and got used to its philosophy and tools. Even then it’ll still do your head in I’ve only just begun to use it in anger and still use PS, but I’m now spending most of my time in PI. I’ve also found that PI’s stacking is excellent too but it’s slow and hence I’m still using AAP for most stacking. My next PI learning hurdle is to integrate multiple sessions!
Alex

[Millsy (Andrew)]

Have a similar setup to you and found that a shorter exposure reduced the star size considerably. I got far more usable subs the second time around. Gain also played a hand. It's nice to see bright subs when taking them but when you get them to processing you really see the good from the bad..

[Doogs38 (Alex)]

Thanks for the advice, Andrew. That's exactly what I trialled recently, ie. shorter exposure and higher gain, and got excellent results. The number of subs I was losing dropped dramatically and I think I've found a goldilocks place for exposure vs gain from my Bortle 5 backyard.

Question: how do you collimate your SCT? Unfocused star? Tri-Bahtinov mask? Both? Something else? I'm using a tri-baht mask and now have all diffraction patterns/spikes centred at the focus point (after some tweaking of the secondary's three screws), I'm presuming that means it's collimated.

Originally Posted by Millsy

Have a similar setup to you and found that a shorter exposure reduced the star size considerably. I got far more usable subs the second time around. Gain also played a hand. It's nice to see bright subs when taking them but when you get them to processing you really see the good from the bad..

[Millsy (Andrew)]

I just use an unfocused star, Canopus is easy to get from my backyard. I havent had the Edge 8 for long and I bought a Hyperstar for it but to be honest I don't want to stuff up my Collimation. Looking for a cheaper C8 so I can have a play with it & introduce myself to some narrowband. The highspeed filters cost a heap.

[Doogs38 (Alex)]

Thanks for the feedback Andrew. The Hyperstar is on my list of things to get - I’ve read good things about them and seen some great results. But, yep, the fast imaging system will challenge the wallet for filters and a good camera too.

Originally Posted by Millsy

I just use an unfocused star, Canopus is easy to get from my backyard. I havent had the Edge 8 for long and I bought a Hyperstar for it but to be honest I don't want to stuff up my Collimation. Looking for a cheaper C8 so I can have a play with it & introduce myself to some narrowband. The highspeed filters cost a heap.

[Dave882 (David)]

Hyperstar is lots of fun- and opens the door to Scts for so many more targets. Guiding is much easier (some don’t even bother) but focus and collimation is extremely challenging. If you’re a pixel perfectionist it could well give you a mental breakdown lol

Andrew- note that changing your sct to Hyperstar does not change the collimation at the secondary mirror, so you don’t need to worry about messing that up. In theory you should be anble to swap back annd forth without needning to do adjustments. However, because collimation needs to be so precise it is prudent to recheck this at the position in the sky you are imaging. For my c14H I need to re collimate on every target if I want reasonable star shapes. At f7 this is rarely necessary. Also note that there is a different connection for the edge hyperstars so be careful if you purchase a new non-edge ota it may not fit.

[Millsy (Andrew)]

Thank you so much for the advice.. Very much appreciated. I would assume the Edge 8 would be a little more forgiving than a C14 ??

[AG Hybrid (Adrian)]

2000mm FL, guiding and 3h of data. This is a beginners picture? What?

This is a complement btw.

Also, some of your other works have over 6 hours of data in multiple wave lengths. Your results speak for themselves.

Where's the line drawn for beginners and the main deep sky images forum?

[Doogs38 (Alex)]

Thanks Adrian. There has been a lot of trial and error plus a very healthy dose of beginners luck me thinks. That said, while I’m very much an astrophotography newbie, I’m not new to photography per se nor image editing which I think has helped a bit Just wish I had more time to fully immerse myself in this magnificent hobby … bring on retirement I say Regards, Alex.

[AdamJL]

That's a first?! You have a hell of a future in this hobby if you're outputting stuff like that! Awesome work.