-Joe_

1st July 2019: Taking Wim's advice 3 hours of RGB. I've also been reading up on gain/exposure for the camera and come across these tables: https://www.cloudynights.com/topic/573886-sub-exposure-tables-for-asi-1600-and-maybe-qhy163/ So change to 120x30s for each of RGB. Gain 139. Stacked in DSS with darks and flats, then processed in StarTools with the R as the luminance. Definitely an imporvement (feels a little overprocessed to me) Just set up for tonight - 3hrs of Ha, and lets see what that adds...

Yeah, that’s my plan this coming weekend. Install raspbian, check out what version of kstars/ekos is in the repo, and then probably try installing and compiling my own.

I find this page useful for figuring out the various adapters: https://astronomy-imaging-camera.com/tutorials/best-back-focus-length-solutions-55mm.html

Like Rick, I just use it on my mac. Comes as a download for kstars - everything included. Worked without any fiddling. There’s a link on the indilib downloads section. Got a raspi4 recently and going to have a play with that and see if I prefer it on a pi or just the laptop. I’m only in the backyard and it’s summer at the moment so no real need for a remote rig. That might change once it’s cold though ;o) and I also want to plan for getting the setup mobile so I can go out to darker skies and better views.

My pi4 arrived today -going to try raspbian and compiling kstars/ekos..

+1 for the ekos fan club. As a real beginner it was simples to sort this all out in ekos.

Thanks @wimvb, plan is tomorrow go for 3 hours RGB.. see wher that gets me, then next night do 3 hours of Ha.. then can compare all 3. Also want to redo my darks. Suspect I did them inside, and may be borked. Will reprocess and see if a better set of darks helps (The comment about black clipping got me thinking..) Have been planning what I call my “black box” so I can get a nice set of darks for reference.

So really enjoying the fun with my Sky-Watcher 72ED. And with a budget in the bank and brexit looming, plan on getting a second scope in the next month or so. I would like to look at smaller objects - planetary nebulas, smaller nebulas, etc. Things that a crop with the 72ED would be too much for. is the only option to get an longer focal length scope - will a Barlow at 3x or 2x just not provide enough light with a 72mm aperture? I also have a NexStar 6SE which can get to 3000mm with a Barlow, but has coma/collimating issues. I can see a few pictures on Astrobin, but not many. However I do have a few bits and pieces around the 1.25” form.. a nice baeder zoom, etc What would you do? Sell the 6SE and buy a refractor for both Astro and visual, keep the 6SE for visual and use the refractor for photos? Any other options? (worth considering Newtonian?) budget is about £1300 + Resale value of the nexstar - has to cover accessories as well. currently thinking skywatcher 120ed-dspro.... but is it worth spending more? Or wait it out and invest time in the 6Se? ideas welcome, cheers joe

Just checked, and zwo call it an m48-m42 adapter, came with my zwo asi1600...

Sorry, just like my astrophotography, those are slightly out of focus...

Here how I connected mine: Telescope -> 2” nosepiece -> 21 & 16mm extenders -> adapter thread -> oag took me a while to figure out the adapter thread - was attached to something else. here’s a photo, not sure if this is the optimal way...

Thanks. Yes unity gain (I think) at 139. Interesting info about the Ha and L frames.. I have a Ha filter on the way, so will give it a go. When you say “several tens per channel” are you talking about reducing the exposure and fitting more frames into the same time, or just increasing the number of 3 min frames? Of course I spent the majority of my time on the L frames, so next clear night might try just RGB frames to compare.

When you say “calibrate them with the dark flats”, do you mean using exactly the same settings apart from a lens cap, or something else?

No help, but, I had the same problem on Weds. same camera and using a white panel to get flats. I threw those flats away in the end. i suspected dew being reflected by the light panel, but far too much of a novice to be in any way certain...

I've spent the past few weeks assembling my astrophoto gear and working out what I need and how I might use it. After all the rubbish weather recently, we got 3 clear nights (if you can call them that this time of year). 25th June 2019: EQ6-Pro Mount, Celestron 6SE scope, ZWO ASI1600MM with L filter. Using Ekos/KStars to control everything from my macbook, I spent a good 3 hours getting a polar alignment. Time for a quick exposure of 30s, pointed at M13 and got, well, something a bit rubbish. But it was *my* rubbish. Processed to hell to at least get something i can look at (StarTools) 26th June 2019: My new SkyWatcher 72ED arrives (still waiting for the flattener). Add a filter wheel and RGB filters, then ZWO OAG and camera. Polar align now took about 30 mins - accurate to 50" according to ekos. Aimed at Brocchi's Cluster, 40x30s of each of LRGB, guided, with darks & dark flats (I'm amazed that worked so easy). Stacked DSS, then StarTools. 27th June 2019: Plan on North American Nebula. Same equipment but 2x binning on RGB this time. Polar alignment is done in 10mins now. 20x3min L, 8x3min each RGB, flats, dark, dark flats. A long way to go yet, but feel I'm actually getting something out of it now.. Criticisms/advice/insults more than welcome , as it's mostly thanks to reading all your discussions/advice that I've got this far.

I guess perspective also comes into it with ‘normal’ photography. As well as fov, how far away you are is a major artistic decision. Not one we can change much with astrophotography.

I would say it relates to the 35mm film. A 50mm lens provides a certain fov on a 35mm film frame (A full frame). Those numbers have ended where they are due to the size of the human eye. ”crop factor” is just a way of relating back to that when trying to sell digital cameras with smaller than 35mm sensors. What really matters is fov, what pixels you have in that fov, and how many photons are arriving. i may be wrong (normally am)...

Found one in stock, ordered, will report back...

Will probably pick one up and use it for kstars/ekos. Lack of USB3 was preventing me from using one of my raspi 3s. I did go to order one when they came out but the 4GB memory version was already sold out...

For mono cameras can LRGB be combined, as long as each is 30s or less?

Very nice colours on the two stars...

Thanks @daemon, EQ DIR cable arrived today and spent a few hours geting it working with KStars/Ekos. But looking good for the first clear night. The EQ Dir cable didnt like being plugged directly in my MacBookPro, but going through a USB3 Hub is just fine...

IIRC, planetary nebula can be viewed from any direction as they are near spherical objects. As the star goes through a later stage of life, expanding into a red giant, it blows off it’s outer layer in a spherical shell. We see this as a ring: Our view through the centre passes through much less gas than one through the edge. I think they are emission objects, with the gas being excited by the light from the star at the centre... but I may be wrong on that... M57 was the first object I saw with my own eyes when I first got a telescope, I still remember the excitement it caused in me, quite unexpectedly..

I did consider the AZ EQ6, but stabilised on the EQ6-R. Ordered from FLO and it arrived today... what a beast. Feels solid, easy to assemble, hard to move... Can't wait to get it into action... just the weather holding me up. Thanks for the advice!

Looks like the eq6-r it is then... Thanks! (the CEM60 looks to be outside my budget, especially after adding a tripod)